Friday, October 30, 2009
Fri-Day 1
Bio 3/6- we reviewed and discussed the three overall purposes of mitosis especially in complex, multi-cellular organisms. We then looked at the final part of our unit: asexual reproduction.
There are FIVE different types of asexual reproduction, ALL of which involve forming genetically identical new cells from the original cells. There is no such thing as male and female in asexual reproduction; there is just one parent cell that is NOT a sex cell.
We saw binary fission that occurs in bacteria, amebas, paramecia, and euglenas. Budding occurs in yeast and hydra. Sporulation in fungi. Regeneration in starfish and planaria. We also discussed THREE types of asexual vegetative propagation, which has the advantage of producing genetically identical offspring of very healthy or delicious plants/veggies/fruits: cutting (as in cutting out the "eyes" of potatoes and planting them), grafting (taking a branch from a seedless orange tree and attaching it firmly to a stem of a healthy orange tree produces more seedless oranges from that branch), and layering (planting part of a vine underground will cause that part of the vine to form a new independent genetically identical plant).
AP Chem- we discussed the requisite definitions to understand Hess's Law. We showed the meaning of enthalpy of formation and gave many examples of various elements in their "standard states" at 1atm and 298 K.
We then showed how and why Hess's Law works by looking at various pathways for a given reaction, seeing that the same NET reaction will always yield the same NET delta H of reaction.
We then applied Hess's Law to get the delta H of reaction from the heats/enthalpies of formation of the reactants and products and their mole coefficients from the BALANCED equation.
The rest of the solutions are in the notes. We will do additional examples next week, of course but you should get started on all of the practice tests, worksheets, and text problems!
See me on Monday about any questions that you cannot solve.
Monday afternoon, I'll give another timed practice test in thermochem and then we'll go over the exam for instant feedback.
There are FIVE different types of asexual reproduction, ALL of which involve forming genetically identical new cells from the original cells. There is no such thing as male and female in asexual reproduction; there is just one parent cell that is NOT a sex cell.
We saw binary fission that occurs in bacteria, amebas, paramecia, and euglenas. Budding occurs in yeast and hydra. Sporulation in fungi. Regeneration in starfish and planaria. We also discussed THREE types of asexual vegetative propagation, which has the advantage of producing genetically identical offspring of very healthy or delicious plants/veggies/fruits: cutting (as in cutting out the "eyes" of potatoes and planting them), grafting (taking a branch from a seedless orange tree and attaching it firmly to a stem of a healthy orange tree produces more seedless oranges from that branch), and layering (planting part of a vine underground will cause that part of the vine to form a new independent genetically identical plant).
AP Chem- we discussed the requisite definitions to understand Hess's Law. We showed the meaning of enthalpy of formation and gave many examples of various elements in their "standard states" at 1atm and 298 K.
We then showed how and why Hess's Law works by looking at various pathways for a given reaction, seeing that the same NET reaction will always yield the same NET delta H of reaction.
We then applied Hess's Law to get the delta H of reaction from the heats/enthalpies of formation of the reactants and products and their mole coefficients from the BALANCED equation.
The rest of the solutions are in the notes. We will do additional examples next week, of course but you should get started on all of the practice tests, worksheets, and text problems!
See me on Monday about any questions that you cannot solve.
Monday afternoon, I'll give another timed practice test in thermochem and then we'll go over the exam for instant feedback.
# posted by C @ 12:36 PM 
Thurs-Day 2
Bio 3/6- we discussed the important overall results of mitosis/cytokinesis. We noted that mitosis/cytokinesis is required for
1.) the GROWTH and/or development of any multicellular/complex organism
and
2.) the REPAIR of damaged cells/tissues/organs of any complex organism.
We then discussed cancer, which is uncontrolled cell division, and how cancer cells harm an organism by using up most of its needed nutrients thus depriving normal cells of nutrients/sources of energy.
AP Chem- We discussed the two types of calorimeters and the relationship between heat and internal energy in each case. For the "bomb" calorimeter, no gaseous P-V work can be done because there can be no change in volume in the sealed steel "bomb"; therefore, the heat absorbed or released is exactly the change in internal energy of the "system"/reactants.
We then did several example of calorimetry, noting whether we had to use "heat capacity" of the calorimeter or specific heat (capacity)of water or of an aqueous solution in the calculation.
We briefly discussed the longer version of Hess's Law; we will learn both versions of his law tomorrow.
1.) the GROWTH and/or development of any multicellular/complex organism
and
2.) the REPAIR of damaged cells/tissues/organs of any complex organism.
We then discussed cancer, which is uncontrolled cell division, and how cancer cells harm an organism by using up most of its needed nutrients thus depriving normal cells of nutrients/sources of energy.
AP Chem- We discussed the two types of calorimeters and the relationship between heat and internal energy in each case. For the "bomb" calorimeter, no gaseous P-V work can be done because there can be no change in volume in the sealed steel "bomb"; therefore, the heat absorbed or released is exactly the change in internal energy of the "system"/reactants.
We then did several example of calorimetry, noting whether we had to use "heat capacity" of the calorimeter or specific heat (capacity)of water or of an aqueous solution in the calculation.
We briefly discussed the longer version of Hess's Law; we will learn both versions of his law tomorrow.
# posted by C @ 12:22 PM
Wednesday, October 28, 2009
Wednes-Day 1
Bio 3/6- we saw an animation of a complete cell cycle including the details of the three parts of interphase, the four phases of mitosis, and the (usually) accompanying cytokinesis.
We drew out these details on a worksheet.
We then continued our discussion of the state osmosis/using indicators lab.
AP Chem- we discussed HOW thermochemical measurements are made: commonly, two different types of calorimeters are used, one is a "coffee cup" calorimeter in which constant pressure conditions are maintained, usually for mixed solutions; the other is a "bomb" calorimeter in which pressure can vary greatly due to the sealed, constant volume condition- this calorimeter is used to combust small samples of a reactant with oxygen.
We tried to invent thermodynamics in the sense that we needed a system by which to define and measure energy changes in a system. We needed something called "specific heat capacity" as well as , for a given particular object, just "heat capacity".
We described the qualitative meaning of substances that have high or low specific heat capacities.
We saw how specific heat is measured for a given substance.
We drew out these details on a worksheet.
We then continued our discussion of the state osmosis/using indicators lab.
AP Chem- we discussed HOW thermochemical measurements are made: commonly, two different types of calorimeters are used, one is a "coffee cup" calorimeter in which constant pressure conditions are maintained, usually for mixed solutions; the other is a "bomb" calorimeter in which pressure can vary greatly due to the sealed, constant volume condition- this calorimeter is used to combust small samples of a reactant with oxygen.
We tried to invent thermodynamics in the sense that we needed a system by which to define and measure energy changes in a system. We needed something called "specific heat capacity" as well as , for a given particular object, just "heat capacity".
We described the qualitative meaning of substances that have high or low specific heat capacities.
We saw how specific heat is measured for a given substance.
# posted by C @ 4:33 PM
Tuesday, October 27, 2009
Tues-Day 2
Bio3/6- using a simplified picture that just focused on the complementary base pairs, we reviewed the DNA replication that takes place during the S part of interphase. We related our picture to what is occurring on the chromosome: the DNA replication LITERALLY forms a second identical "sister chromatid" making the chromosome go from a single-chromatid chromosome to a double-chromatid chromosome. Without this important formation of identical sister chromatids, mitosis could NOT occur because the daughter cells would not have the same number and types of chromosomes as the original cell due to the lack of DNA; thus not all of the required proteins and enzymes necessary for metabolism/homeostasis would be coded for and synthesized i.e. the new cells could not live.
We then discussed the importance of the Watson-Crick model/picture of DNA, showing how it explained/accounted for the ability of cells to reproduce identical cells with the same genetic information and also how DNA could code information that is translated into the specific amino acid sequence of all of the proteins that give an organism its specific traits and characteristics.
AP Chem- we reviewed the 0-th and 1st Laws of Thermodynamics, emphasizing the importance of understanding the SIGNS of heat and work with respect to the system. Once those signs are understood/felt, the math version of the 1st Law dE = q + w has to work and make sense. For example, if a system ABSORBS heat ( q is positive ), then the change in internal energy of the system MUST be positive due to the energy absorbed. If a system DOES WORK i.e. pushes a piston (w is negative), then that system LOSES energy (in order to do the work, it uses up some of its energy!) so the change in internal energy is negative. If both work and heat are involved, there may be a NET gain or loss of internal system energy depending on which value is greater and the sign of those values.
We then discussed ENTHALPY, which is a measure of the potential energy of the system's particles. The more stable the particles, due to MORE and STRONGER bonds, the LOWER the ENTHALPY of the system's particles. We can't measure absolute enthalpies (though we do DEFINE certain values, as you will see), we CAN via calorimetry, measure CHANGES in enthalpy, delta H, which we sometimes call the "heat of reaction" or "heat of some process".
We noted that change in enthalpy MUST BE measured ONLY under CONSTANT PRESSURE conditions and the ONLY type of work that can occur is gaseous pressure-volume work.
We discussed thermochemical equations and did stoichiometric examples involving the heat/energy absorbed or released from various quantities of reactants or products.
DO NOT FORGET that the delta H value given for a reaction is PER MOLE of "reaction"; that is, for the reaction 2A + B --> 3C + D ; delta H = -255 kJ , one MOLE of reaction means that TWO moles of "A" reacted, ONE mole of "B" reacted, THREE moles of "C" formed, and ONE mole of "D" formed AND that 255 kJ of energy were released to the surroundings.
We then did some stoichiometry with the thermochemical equations, focusing on the proper placement of the energy term and noting that the quantities are treated in the exact same way as they are treated in any stoichiometry problem (especially be careful to look for limiting reactants that limit the energy absorbed or released!).
We then discussed the importance of the Watson-Crick model/picture of DNA, showing how it explained/accounted for the ability of cells to reproduce identical cells with the same genetic information and also how DNA could code information that is translated into the specific amino acid sequence of all of the proteins that give an organism its specific traits and characteristics.
AP Chem- we reviewed the 0-th and 1st Laws of Thermodynamics, emphasizing the importance of understanding the SIGNS of heat and work with respect to the system. Once those signs are understood/felt, the math version of the 1st Law dE = q + w has to work and make sense. For example, if a system ABSORBS heat ( q is positive ), then the change in internal energy of the system MUST be positive due to the energy absorbed. If a system DOES WORK i.e. pushes a piston (w is negative), then that system LOSES energy (in order to do the work, it uses up some of its energy!) so the change in internal energy is negative. If both work and heat are involved, there may be a NET gain or loss of internal system energy depending on which value is greater and the sign of those values.
We then discussed ENTHALPY, which is a measure of the potential energy of the system's particles. The more stable the particles, due to MORE and STRONGER bonds, the LOWER the ENTHALPY of the system's particles. We can't measure absolute enthalpies (though we do DEFINE certain values, as you will see), we CAN via calorimetry, measure CHANGES in enthalpy, delta H, which we sometimes call the "heat of reaction" or "heat of some process".
We noted that change in enthalpy MUST BE measured ONLY under CONSTANT PRESSURE conditions and the ONLY type of work that can occur is gaseous pressure-volume work.
We discussed thermochemical equations and did stoichiometric examples involving the heat/energy absorbed or released from various quantities of reactants or products.
DO NOT FORGET that the delta H value given for a reaction is PER MOLE of "reaction"; that is, for the reaction 2A + B --> 3C + D ; delta H = -255 kJ , one MOLE of reaction means that TWO moles of "A" reacted, ONE mole of "B" reacted, THREE moles of "C" formed, and ONE mole of "D" formed AND that 255 kJ of energy were released to the surroundings.
We then did some stoichiometry with the thermochemical equations, focusing on the proper placement of the energy term and noting that the quantities are treated in the exact same way as they are treated in any stoichiometry problem (especially be careful to look for limiting reactants that limit the energy absorbed or released!).
# posted by C @ 11:59 PM
Monday, October 26, 2009
Mon-Day 1
Bio 3/6- I'll upload today's notes when I get home to my tablet pc :)
We discussed the "S" phase of interphase and showed how the DNA that makes up a chromosome can exactly replicate itself. Each double-helix DNA molecule "unzips" with the help of an enzyme that quickly "breaks" the "hydrogen bonds" that keep the two chains of complementary nucleotides attracted to each other. Then, the free-floating nucleotide building blocks in the nucleus that are randomly moving around eventually are attracted to and paired with their exposed complementary base partners on each of the two unzipped strands.
The result is a "double-chromatid" chromosome that will eventually pulled apart into TWO identical chromosomes when the cell undergoes mitosis and cytokinesis.
AP Chem- we reviewed some earlier definitions and then did a couple of First Law of Thermo problems, noting the meaning, value, and signs of q and w. We also associated ENTHALPY, H, with the heat gained or lost by the system at CONSTANT pressure.
We further associated H with potential energy as the result of the stability (number and strength of bonds or attractions) of the system.
The result is a "double-chromatid" chromosome that will eventually pulled apart into TWO identical chromosomes when the cell undergoes mitosis and cytokinesis.
AP Chem- we reviewed some earlier definitions and then did a couple of First Law of Thermo problems, noting the meaning, value, and signs of q and w. We also associated ENTHALPY, H, with the heat gained or lost by the system at CONSTANT pressure.
We further associated H with potential energy as the result of the stability (number and strength of bonds or attractions) of the system.
# posted by C @ 1:16 PM
Friday, October 23, 2009
Fri-Day 2
Bio 3/6 - we started our new unit on DNA, the Cell Cycle, and Asexual Reproduction with a look at the life cycle of cells. Cells spend most of their time growing, carrying out the various life functions, and then, as they are getting to big to sustain a sufficient rate of metabolic reactions, synthesize/duplicate their genetic material/DNA to prepare to divide. Once the cell divides into two identical, yet smaller cells, the new life cycle of each of the two cells begins.
We discussed the two reasons that cells must divide or die.
We then began our discussion on DNA replication. We reviewed the structure of DNA: TWO strands of chains of nucleotides that are COMPLEMENTARY to each other and are held together by weak hydrogen "bonds" (which are NOT bonds, can you believe that!? Wait until I am in power...), which I will call "attractions".
AP Chem- we continued our discussion of state functions; we then showed how gases can do work by exerting force against container walls i.e. pressure-volume work. We converted L-atm work units to Joules and emphasized the SIGNS that a gas doing work is LOSING internal energy so the sign of work will be NEGATIVE (Joules), whereas work being done ON a gas via COMPRESSION is the same as giving energy TO the gas, thus increasing its internal energy so the sign will be POSITIVE.
We then started our redox titration lab by calculating the proper quantities needed to make a liter of approximately .100 M sodium thiosulfate.
We discussed the two reasons that cells must divide or die.
We then began our discussion on DNA replication. We reviewed the structure of DNA: TWO strands of chains of nucleotides that are COMPLEMENTARY to each other and are held together by weak hydrogen "bonds" (which are NOT bonds, can you believe that!? Wait until I am in power...), which I will call "attractions".
AP Chem- we continued our discussion of state functions; we then showed how gases can do work by exerting force against container walls i.e. pressure-volume work. We converted L-atm work units to Joules and emphasized the SIGNS that a gas doing work is LOSING internal energy so the sign of work will be NEGATIVE (Joules), whereas work being done ON a gas via COMPRESSION is the same as giving energy TO the gas, thus increasing its internal energy so the sign will be POSITIVE.
We then started our redox titration lab by calculating the proper quantities needed to make a liter of approximately .100 M sodium thiosulfate.
# posted by C @ 11:21 PM
Thursday, October 22, 2009
Thurs-Day 1
Bio 3/6- took the unit exam on Cells and Cell Processes, especially active and passive transport.
We finished our discussion of the Plant vs. Animal Cell Lab.
AP Chemistry- began our new unit on Thermochemistry by discussing the meaning of the term "state function" (independent of the path/method of getting to a particular "state"). We defined energy, and the state function, E, "internal energy", which is the sum total of all of the types of energy that a system possesses.
We finished our discussion of the Plant vs. Animal Cell Lab.
AP Chemistry- began our new unit on Thermochemistry by discussing the meaning of the term "state function" (independent of the path/method of getting to a particular "state"). We defined energy, and the state function, E, "internal energy", which is the sum total of all of the types of energy that a system possesses.
# posted by C @ 9:50 PM
Wednesday, October 21, 2009
Wednes-Day 2
Bio 3/6- Don't forget to take advantage of extra help in Room 301 tomorrow morning at 8:15 AM! Tomorrow, we take the unit 3 exam on Cells and Cell Processes (with an emphasis on types of active and passive transport).
I put up more review worksheets on Blackboard, which you can use to help reinforce concepts and information and to prepare your "cheatsheet" (that you put away just before the test) for tomorrow.
Check out the videos and powerpoints because, as is the case on many tests, you will see pictures and diagrams in which you will have to know the shapes/structures of the parts or organelles.
AP Chem- took our comprehensive Gas Unit exam.
We start Thermochemistry tomorrow.
I put up more review worksheets on Blackboard, which you can use to help reinforce concepts and information and to prepare your "cheatsheet" (that you put away just before the test) for tomorrow.
Check out the videos and powerpoints because, as is the case on many tests, you will see pictures and diagrams in which you will have to know the shapes/structures of the parts or organelles.
AP Chem- took our comprehensive Gas Unit exam.
We start Thermochemistry tomorrow.
# posted by C @ 11:03 AM
Tuesday, October 20, 2009
Tues-Day 1
Bio 3/6 -we showed how chemical indicators can be used to show evidence of diffusion of various substances such as glucose and starch.
We then did a lab using easily visible plant cells (red onion cells) to see osmosis under hypertonic and hypotonic solution conditions.
AP Chem- we started a marathon gas unit problem covering most of the quantitative aspects of the unit.
Momentarily, I will post the question types that will be on tomorrow's exam.
The test covers
1. Gas stoichiometry with emphasis on applying the gas laws to determine moles and masses of reactants and products. There will be a repeat of the question part involving the determination of all aqueous ion concentrations after a reaction has gone to completion.
2. Descriptive chemistry of the four "gas-forming reactions".
3. Explanation, in terms of (a) molecular collision frequency and (b) molecular collision force/kinetic energy, of any permutation of the ideal gas law.
4. Graham's Law of Effusion in terms of relative rates OR times for different gases.
5. Average (rms) speed of a gaseous molecule of a substance at a given temperature.
6. Dalton's Law questions involving partial pressure, mole fraction, and total pressure.
7. Van der Waal's gas equation and the explanation of the magnitude of the "a" and "b" correction factors of a given substance.
8. the postulates of kinetic-molecular theory relating to the how and why a real gas will behave ideally or will deviate from ideal behavior.
We then did a lab using easily visible plant cells (red onion cells) to see osmosis under hypertonic and hypotonic solution conditions.
AP Chem- we started a marathon gas unit problem covering most of the quantitative aspects of the unit.
Momentarily, I will post the question types that will be on tomorrow's exam.
The test covers
1. Gas stoichiometry with emphasis on applying the gas laws to determine moles and masses of reactants and products. There will be a repeat of the question part involving the determination of all aqueous ion concentrations after a reaction has gone to completion.
2. Descriptive chemistry of the four "gas-forming reactions".
3. Explanation, in terms of (a) molecular collision frequency and (b) molecular collision force/kinetic energy, of any permutation of the ideal gas law.
4. Graham's Law of Effusion in terms of relative rates OR times for different gases.
5. Average (rms) speed of a gaseous molecule of a substance at a given temperature.
6. Dalton's Law questions involving partial pressure, mole fraction, and total pressure.
7. Van der Waal's gas equation and the explanation of the magnitude of the "a" and "b" correction factors of a given substance.
8. the postulates of kinetic-molecular theory relating to the how and why a real gas will behave ideally or will deviate from ideal behavior.
# posted by C @ 5:40 PM
Monday, October 19, 2009
Mon-Day 2
Bio 3/6- the following hw objectives will NOT be due tomorrow:
17. What is the function of a transport protein and how does it perform its
function? Give a specific example of a transport protein performing its
function.
18. What phenomena with respect to diffusion were observed during the NY
State Regents lab on the “onion cell”?
Today, we discussed the two general types of transport of substances into or out of cells: active transport ( e.g. lower to higher concentration NET movement of a substance; also, phagocytosis, pinocytosis, endocytosis, and exocytosis) AND passive transport (e.g. higher to lower concentration NET movement of a substance; diffusion, diffusion-of-water=osmosis, and facilitated diffusion.
We also looked at three examples of osmosis in HYPOtonic (too little solute, HIGHER WATER concentration/percentage) solution, ISOtonic solution, and HYPERtonic (too much solute, LOWER WATER concentration/percentage). We showed that differences in water concentration CAUSED different RATES of water flow into the cell than out of the cell causing the cell to either swell with water (and possible lysis, for animal cells), stay the same, or shrink due to water loss.
The SOLUTE particles/salt ions are NOT generally permeable (CANNOT PASS THROUGH) cell membranes (phospholipids) other than by ACTIVE TRANSPORT through a specialized TRANSPORT PROTEIN; this is why we had to focus ONLY on the net WATER movement.
Tomorrow, we will do a lab showing this type of phenomenon.
AP Chem- we did another Graham's Law problem in which we determined the molar mass of an unknown gas based on its time to diffuse from a balloon. We then derived the formula for average speed of a gas phase molecule at a particular temperature. We had to do unit analysis and tweak the "3" to a "3000" in the formula so that we could still use the NORMAL measurement of molar mass in "grams per mole".
We discussed kinetic molecular theory that explains and predicts the behavior of gases and also can explain how and why gases deviate from ideal behavior.
We then discussed Vanderwaal's modified gas equation that uses experimentally determined correction factors for real gases so that ideal gas law calculations can be accurately applied.
We discussed the meaning of each of the correction factors and their place in the equation.
17. What is the function of a transport protein and how does it perform its
function? Give a specific example of a transport protein performing its
function.
18. What phenomena with respect to diffusion were observed during the NY
State Regents lab on the “onion cell”?
Today, we discussed the two general types of transport of substances into or out of cells: active transport ( e.g. lower to higher concentration NET movement of a substance; also, phagocytosis, pinocytosis, endocytosis, and exocytosis) AND passive transport (e.g. higher to lower concentration NET movement of a substance; diffusion, diffusion-of-water=osmosis, and facilitated diffusion.
We also looked at three examples of osmosis in HYPOtonic (too little solute, HIGHER WATER concentration/percentage) solution, ISOtonic solution, and HYPERtonic (too much solute, LOWER WATER concentration/percentage). We showed that differences in water concentration CAUSED different RATES of water flow into the cell than out of the cell causing the cell to either swell with water (and possible lysis, for animal cells), stay the same, or shrink due to water loss.
The SOLUTE particles/salt ions are NOT generally permeable (CANNOT PASS THROUGH) cell membranes (phospholipids) other than by ACTIVE TRANSPORT through a specialized TRANSPORT PROTEIN; this is why we had to focus ONLY on the net WATER movement.
Tomorrow, we will do a lab showing this type of phenomenon.
AP Chem- we did another Graham's Law problem in which we determined the molar mass of an unknown gas based on its time to diffuse from a balloon. We then derived the formula for average speed of a gas phase molecule at a particular temperature. We had to do unit analysis and tweak the "3" to a "3000" in the formula so that we could still use the NORMAL measurement of molar mass in "grams per mole".
We discussed kinetic molecular theory that explains and predicts the behavior of gases and also can explain how and why gases deviate from ideal behavior.
We then discussed Vanderwaal's modified gas equation that uses experimentally determined correction factors for real gases so that ideal gas law calculations can be accurately applied.
We discussed the meaning of each of the correction factors and their place in the equation.
# posted by C @ 1:43 PM
Saturday, October 17, 2009
Fri-Day 1
Bio 3/6 - we did another example of organelles working together to maintain cellular or an organism's homeostasis. We then discussed the various levels of organization of cells required to keep complex, multi-celled organisms alive; specialized cells in organized collections called tissues, then more complex organs, and even more complex organ systems are needed because different parts of the body are in very different chemical and physical environments. A single-celled organism has only a single local environment, because the cell is so small.
We then began one of the most important parts of this unit: cell transport.
Check out the videos posted on Blackboard that show diffusion, diffusion-of-water=osmosis, "facilitated"=assisted diffusion, and active transport (requires ATP).
AP Chem- we finished the discussion of the gas laws by explaining that adding another gas to a container will increase total pressure but will NOT affect the collision frequency and force (i.e. partial PRESSURE) of the OTHER gas or gases already in there.
We then derived Graham's Law of Effusion/Diffusion by considering the mathematical formula for KINETIC ENERGY. At a given temperature/average kinetic energy, the greater the molecular mass of a molecule, the slower its average velocity, thus the lower its rate of effusion/diffusion. We then applied the formula to compare the relative rates of effusion of two different gases.
We then began one of the most important parts of this unit: cell transport.
Check out the videos posted on Blackboard that show diffusion, diffusion-of-water=osmosis, "facilitated"=assisted diffusion, and active transport (requires ATP).
AP Chem- we finished the discussion of the gas laws by explaining that adding another gas to a container will increase total pressure but will NOT affect the collision frequency and force (i.e. partial PRESSURE) of the OTHER gas or gases already in there.
We then derived Graham's Law of Effusion/Diffusion by considering the mathematical formula for KINETIC ENERGY. At a given temperature/average kinetic energy, the greater the molecular mass of a molecule, the slower its average velocity, thus the lower its rate of effusion/diffusion. We then applied the formula to compare the relative rates of effusion of two different gases.
# posted by C @ 6:32 AM
Thursday, October 15, 2009
Thurs-Day 2
Bio 3/6- we discussed the need for organelles in a cell to work together in order to maintain homeostasis/keep the cell alive: no single organelle can perform all of the required life functions that keep the cell alive.
We then discussed a couple of prime examples of HOW two or more organelles work together in order help maintain homeostasis. Often pairs of organelles will mutually help each other perform their functions by having one organelle make components or supply energy that is required by the other organelle and vice-versa.
Tomorrow, we will discuss levels of organization in complex organisms and also focus on the modes of transport of substances into and out of the "selective" cell membrane.
AP Chem- we had a detailed discussion of what CAUSES pressure in a container of a sample of gas. By focusing on the 1. pressure causing collision frequency of the gas particles with the container wall and 2. the pressure causing kinetic energy/force of the collisions, we can explain/reason any of the gas laws. Check out the animation of the gas laws on Blackboard (remind me to show them in class, thanks).
The percent composition of a hydrate lab writeup is due in class tomorrow.
We still have Graham's Law of Effusion and the Van der Waal's "corrected" real gas equation to finish up this unit. The unit exam will be given next Wednesday and an after school TIMED practice will be given on Monday.
We then discussed a couple of prime examples of HOW two or more organelles work together in order help maintain homeostasis. Often pairs of organelles will mutually help each other perform their functions by having one organelle make components or supply energy that is required by the other organelle and vice-versa.
Tomorrow, we will discuss levels of organization in complex organisms and also focus on the modes of transport of substances into and out of the "selective" cell membrane.
AP Chem- we had a detailed discussion of what CAUSES pressure in a container of a sample of gas. By focusing on the 1. pressure causing collision frequency of the gas particles with the container wall and 2. the pressure causing kinetic energy/force of the collisions, we can explain/reason any of the gas laws. Check out the animation of the gas laws on Blackboard (remind me to show them in class, thanks).
The percent composition of a hydrate lab writeup is due in class tomorrow.
We still have Graham's Law of Effusion and the Van der Waal's "corrected" real gas equation to finish up this unit. The unit exam will be given next Wednesday and an after school TIMED practice will be given on Monday.
# posted by C @ 1:51 PM
Wednesday, October 14, 2009
Wednes-Day 1
Bio 3/6- we compared and contrasted: prokaryotic vs. eukaryotic cells and also plant vs. animal cells. We saw videos that showed the various cell organelles and their functions.
We performed a microscopy procedure on human cheek epithelial cells and Elodea plant cells, practicing our staining techniques to better see the nuclei and membranes of the cells.
AP Chem- The Percent Composition of a Hydrate Lab WRITEUP is due on Friday, in class.
We finished the Dalton's Law stoichiometry problem. We then derived each of the gas laws from the ideal gas law by holding certain pairs of variables constant. We also explained what was occurring at the molecular level in terms of collision frequency and kinetic energy/force of collisions. We also showed, graphically, the relationship between each pair of variables.
I expect to see at extra help those of you who are making many errors on the unit exams; you clearly need to prepare more before each exam and you have not done so.
We performed a microscopy procedure on human cheek epithelial cells and Elodea plant cells, practicing our staining techniques to better see the nuclei and membranes of the cells.
AP Chem- The Percent Composition of a Hydrate Lab WRITEUP is due on Friday, in class.
We finished the Dalton's Law stoichiometry problem. We then derived each of the gas laws from the ideal gas law by holding certain pairs of variables constant. We also explained what was occurring at the molecular level in terms of collision frequency and kinetic energy/force of collisions. We also showed, graphically, the relationship between each pair of variables.
I expect to see at extra help those of you who are making many errors on the unit exams; you clearly need to prepare more before each exam and you have not done so.
# posted by C @ 11:25 PM
Tuesday, October 13, 2009
Tues-Day 2
Bio 3/6- we reviewed the structure and function of 10 cell organelles and then added 4 more to our list: chloroplasts, cilia/flagella, centrioles, and Golgi bodies.
We began to review/compare and contrast prokaryotic and eukaryotic cells.
AP Chem- we did a Dalton's Law of Partial Pressure/Ideal Gas Law problem involving a gas collected over water, a process that automatically introduces water vapor as one of the gases contributing to the total pressure.
We then did a gas stoichiometry problem involving a conventional "two-bulb" setup in which the gases are initially separated, each with unique conditions, and then combined and (usually) reacted.
I will post MANY review problems with fully detailed solutions.
We began to review/compare and contrast prokaryotic and eukaryotic cells.
AP Chem- we did a Dalton's Law of Partial Pressure/Ideal Gas Law problem involving a gas collected over water, a process that automatically introduces water vapor as one of the gases contributing to the total pressure.
We then did a gas stoichiometry problem involving a conventional "two-bulb" setup in which the gases are initially separated, each with unique conditions, and then combined and (usually) reacted.
I will post MANY review problems with fully detailed solutions.
# posted by C @ 3:15 PM
Saturday, October 10, 2009
Fri-Day 1
Bio 3/6- we discussed the tenets of Cell Theory and their exceptions. We then discussed the two main types of cells: prokaryotic (NO nucleus) and eukaryotic (eu=true); we discussed several differences between these cell types.
We then took a tour of the structure and function of several organelles common to eukaryotic cells: the nucleus, the rough and smooth ER, the mitochondria, the Golgi apparatus/bodies, lysosomes, and vacuoles.
We did some test review showing that, to give a sufficient answer to any question (especially an explanation question), you must use/address the SPECIFIC key terms in the question and you must show how and why these terms relate to what is asked for.
Graphing skills were generally very good and improving. Identifying key terms and drawing out what is asked for could still be improved in order to keep you focused on what suffices for a correct answer.
AP Chem- we continued the gas laws solving for the molar mass of a substance given its temperature, pressure, volume, and mass (while it is in the gas phase).
We then discussed two versions of Dalton's Law that show pressure and mole relationships in a mixture of gases.
See Blackboard for more practice with this.
We then took a tour of the structure and function of several organelles common to eukaryotic cells: the nucleus, the rough and smooth ER, the mitochondria, the Golgi apparatus/bodies, lysosomes, and vacuoles.
We did some test review showing that, to give a sufficient answer to any question (especially an explanation question), you must use/address the SPECIFIC key terms in the question and you must show how and why these terms relate to what is asked for.
Graphing skills were generally very good and improving. Identifying key terms and drawing out what is asked for could still be improved in order to keep you focused on what suffices for a correct answer.
AP Chem- we continued the gas laws solving for the molar mass of a substance given its temperature, pressure, volume, and mass (while it is in the gas phase).
We then discussed two versions of Dalton's Law that show pressure and mole relationships in a mixture of gases.
See Blackboard for more practice with this.
# posted by C @ 9:59 AM
Thursday, October 8, 2009
Thurs-Day 2
Bio 3/6- we began our unit on cells by discussing the unity of all living things: all organisms, large or small, simple or complex, consist of one or more basic living units called cells.
We discussed the relationship between advances in technology, especially in microscopy techniques and equipment, that enabled discoveries of cells and organelles within cells.
We explained the evidence and three tenets of Cell Theory and exceptions to this Theory.
AP Chem- took our second stoichiometry exam: solutions and redox.
The new unit study guide and objectives are posted on Blackboard.
We discussed the relationship between advances in technology, especially in microscopy techniques and equipment, that enabled discoveries of cells and organelles within cells.
We explained the evidence and three tenets of Cell Theory and exceptions to this Theory.
AP Chem- took our second stoichiometry exam: solutions and redox.
The new unit study guide and objectives are posted on Blackboard.
# posted by C @ 12:49 PM
Wednesday, October 7, 2009
Wednes-Day 1
Bio 3/6 - we finished up our discussions of the pH indicator and catalase enzyme activity labs.
We will begin the unit on the Cell and Cell Processes tomorrow.
AP Chem- there will be no "gas forming reaction" descriptive chemistry questions on tomorrow's exam. You are still responsible, though, for knowing the solubility rules and double replacement with precipitation equations (formula and net ionic).
Tomorrow's exam will have redox balancing, stoichiometry, molarity calculations, dilutions, limiting reactant, and mixture analysis questions, the same types of questions that you saw in the class notes and in the practice files (and the "ordinary" hw questions).
Today, we finished yet another redox solution stoichiometry problem in which we identified the limiting reactant as well as the final concentrations of any aqueous ions that remained.
Note: all of these calculations assume no significant REVERSE reaction. This assumption is practically true for certain reactions (gas formation, precipitate formation, neutralization) but will not hold for the reactions that we study later this year in the "equilibrium" unit.
We also discussed some of the hydrate lab questions by showing how to quantitatively (use sample calcs) and qualitatively explain unintentional and random experimental "error".
We will begin the unit on the Cell and Cell Processes tomorrow.
AP Chem- there will be no "gas forming reaction" descriptive chemistry questions on tomorrow's exam. You are still responsible, though, for knowing the solubility rules and double replacement with precipitation equations (formula and net ionic).
Tomorrow's exam will have redox balancing, stoichiometry, molarity calculations, dilutions, limiting reactant, and mixture analysis questions, the same types of questions that you saw in the class notes and in the practice files (and the "ordinary" hw questions).
Today, we finished yet another redox solution stoichiometry problem in which we identified the limiting reactant as well as the final concentrations of any aqueous ions that remained.
Note: all of these calculations assume no significant REVERSE reaction. This assumption is practically true for certain reactions (gas formation, precipitate formation, neutralization) but will not hold for the reactions that we study later this year in the "equilibrium" unit.
We also discussed some of the hydrate lab questions by showing how to quantitatively (use sample calcs) and qualitatively explain unintentional and random experimental "error".
# posted by C @ 1:50 PM
Tuesday, October 6, 2009
Tues-Day 2
Bio 3/6- we took our unit exam on Biochemistry.
AP Chem- we discussed the behavior of gases at the particle level and why any ideally behaving substance will follow the gas laws. All gas phase substances have particles that collide with each other and the walls of the container with a particular force and frequency causing pressure in the container. We reasoned the relationship between moles of a gas and pressure (direct), temperature of a gas and pressure (direct) all in terms of collision frequency and average force of collisions.
We then wrote out the ideal gas law, examined the units and conversions, derived a similar version of the ideal gas law that solves from molar mass of the gaseous substance, and used the law in a stoichiometry problem.
We did a comprehensive review redox solution stoichiometry problem that we will continue tomorrow.
AP Chem- we discussed the behavior of gases at the particle level and why any ideally behaving substance will follow the gas laws. All gas phase substances have particles that collide with each other and the walls of the container with a particular force and frequency causing pressure in the container. We reasoned the relationship between moles of a gas and pressure (direct), temperature of a gas and pressure (direct) all in terms of collision frequency and average force of collisions.
We then wrote out the ideal gas law, examined the units and conversions, derived a similar version of the ideal gas law that solves from molar mass of the gaseous substance, and used the law in a stoichiometry problem.
We did a comprehensive review redox solution stoichiometry problem that we will continue tomorrow.
# posted by C @ 11:55 AM
Monday, October 5, 2009
Mon-Day 1
Bio 3/6- we reviewed for tomorrow's Biochemistry unit exam.
We went over the most common hw errors. USE the Blackboard videos/animations FIRST to study for tomorrow's exam. Then go over your hw and notes and do any practice quizzes on Blackboard, if you have not already done so.
You should go over the LAST exam's corrections to remind yourself about test-taking skills, graph skills, and scientific method skills.
We almost finished our discussion of the pH lab, which we will complete on Wednesday.
AP Chem- we finished the four main/common gas forming reactions in descriptive chemistry and balanced their net ionic equations.
We then began our unit on gases and gas stoichiometry (NOT on Thursday's exam).
A practice exam without answers has been posted to accompany the hundred or so questions (that can make up a lot of practice exams) WITH fully detailed answers that have been posted.
We went over the most common hw errors. USE the Blackboard videos/animations FIRST to study for tomorrow's exam. Then go over your hw and notes and do any practice quizzes on Blackboard, if you have not already done so.
You should go over the LAST exam's corrections to remind yourself about test-taking skills, graph skills, and scientific method skills.
We almost finished our discussion of the pH lab, which we will complete on Wednesday.
AP Chem- we finished the four main/common gas forming reactions in descriptive chemistry and balanced their net ionic equations.
We then began our unit on gases and gas stoichiometry (NOT on Thursday's exam).
A practice exam without answers has been posted to accompany the hundred or so questions (that can make up a lot of practice exams) WITH fully detailed answers that have been posted.
# posted by C @ 3:51 PM
Sunday, October 4, 2009
AP Chem help
Just posted, on Blackboard, files containing dozens and dozens of solution stoichiometry questions with complete/detailed answers. Use these examples for extra practice before Thursday's unit exam and as a guide to help you with your homework, which is due Tuesday.
Also, to help you hone your compound naming/ formula writing skills, I posted a review sheet containing 200 practice questions (with answers) on that topic.
Also, to help you hone your compound naming/ formula writing skills, I posted a review sheet containing 200 practice questions (with answers) on that topic.
# posted by C @ 3:34 PM
Friday, October 2, 2009
Fri-Day 2
Bio 3/6- we finished our description of the structure and function of nucleic acids, DNA and RNA. We saw that nucleic acids are chains of nucleotides that are bound together (with the help of nucle-ases) forming a double-helix of two complementary chains (DNA) or a single-helix (RNA).
The sugar-phosphate "rungs" of the DNA or RNA ladder do not vary at all but the NITROGENOUS BASE sequence enables nucleic acid molecules to code information that directs the making of the specific proteins that characterize a given organism.
We then started our test review.
On Monday, we will review and complete our unit labs (though I will postpone the Alamain discussion until after our test).
AP Chem- see Blackboard for more solved solution stoichiometry problems as well as the FIVE homework questions, Chapter 4 in your text, questions 76, 88, 92, 94, 96 that will be collected next Tuesday in class. Show ALL work including units and their cancellation, substances, phases, attention to sig figs in the FINAL answer, drawings, balancing steps, etc.
We did two more solution stoichiometry problems: one in which we determined the empirical formula of an acid by titrating it with a known base and the other in which we dissolved and analyzed the mass percent of iron in an iron ore via redox titration.
The sugar-phosphate "rungs" of the DNA or RNA ladder do not vary at all but the NITROGENOUS BASE sequence enables nucleic acid molecules to code information that directs the making of the specific proteins that characterize a given organism.
We then started our test review.
On Monday, we will review and complete our unit labs (though I will postpone the Alamain discussion until after our test).
AP Chem- see Blackboard for more solved solution stoichiometry problems as well as the FIVE homework questions, Chapter 4 in your text, questions 76, 88, 92, 94, 96 that will be collected next Tuesday in class. Show ALL work including units and their cancellation, substances, phases, attention to sig figs in the FINAL answer, drawings, balancing steps, etc.
We did two more solution stoichiometry problems: one in which we determined the empirical formula of an acid by titrating it with a known base and the other in which we dissolved and analyzed the mass percent of iron in an iron ore via redox titration.
# posted by C @ 11:00 AM
Thursday, October 1, 2009
Thurs-Day 1
Bio 3/6- we explained and illustrated the effect of increasing enzyme concentration on the rate of enzyme activity/reaction given a set/constant concentration of its (complementary shaped) substrate; we showed that the reaction would increase with increasing enzyme concentration but would eventually reach a maximum rate and remain constant at that maximum even at higher enzyme concentration because there is only a limited quantity of substrate that can be catalyzed by a certain number of enzymes at once; any excess enzyme molecules would have no substrate to crash into and catalyze/help to hydrolyze.
We saw the same type of relationship when the concentration of enzyme is held constant and the concentration of substrate is increased. Eventually, all of the enzymes are "occupied"/saturated/temporarily bound to the substrate molecules so that any excess substrate will not be catalyzed; thus, at that point, the reaction rate remains constant at a maximum.
We then discussed the necessity and function of coenzymes that must bind to their inactive partner enzymes in order to "complete" the enzyme and make its "active site" the complementary shape of its substrate.
We made it to the last major important organic biomolecule type: nucleic acids.
DNA and RNA are the two main types of nucleic acids; there are small but significant differences between DNA and RNA: DNA is a double helix shaped polymer of nucleotides, RNA is a single helix shaped polymer of nucleotides; DNA contains the nitrogenous bases A,T,G, and C whereas RNA contains only A, U, G, and C.
Nucleic acids are made up of building blocks called nucleotides; each nucleotide has three components bonded together: a phosphate group, a 5-membered ring sugar, and a nitrogenous base. DNA has the Deoxyribose sugar, RNA has the Ribose sugar.
AP Chem- we finished our alkane combustion mixture problem and then did a mixture of two sulfide salts problem.
We saw the same type of relationship when the concentration of enzyme is held constant and the concentration of substrate is increased. Eventually, all of the enzymes are "occupied"/saturated/temporarily bound to the substrate molecules so that any excess substrate will not be catalyzed; thus, at that point, the reaction rate remains constant at a maximum.
We then discussed the necessity and function of coenzymes that must bind to their inactive partner enzymes in order to "complete" the enzyme and make its "active site" the complementary shape of its substrate.
We made it to the last major important organic biomolecule type: nucleic acids.
DNA and RNA are the two main types of nucleic acids; there are small but significant differences between DNA and RNA: DNA is a double helix shaped polymer of nucleotides, RNA is a single helix shaped polymer of nucleotides; DNA contains the nitrogenous bases A,T,G, and C whereas RNA contains only A, U, G, and C.
Nucleic acids are made up of building blocks called nucleotides; each nucleotide has three components bonded together: a phosphate group, a 5-membered ring sugar, and a nitrogenous base. DNA has the Deoxyribose sugar, RNA has the Ribose sugar.
AP Chem- we finished our alkane combustion mixture problem and then did a mixture of two sulfide salts problem.
# posted by C @ 12:03 PM
