SciHawks

AP Chem- we reviewed (again) Coulomb's Law as it applies to ionic bonding.
We discussed the difference between a polar BOND and a polar MOLECULE, using CO2 as an example, due to its molecular geometry, of a molecule that has polar BONDS yet is a nonpolar molecule.
We then discussed various ways of collecting DATA that indicated the strength of ionic bonding in an ionic compound i.e. melting point, solubility in water, etc.
We saw that the Born-Haber multi-step process is a way that we can apply Hess's Law to also get a measure of the strength of ionic bonding in a salt or hydroxide base called "lattice energy".
Lattice energy is the energy RELEASED when a MOLE of a SOLID ionic compound forms from its IONS in the GAS phase.

Bio 6-8 - we finished our review of the digestive system by discussing the structure and function of the colon/large intestine. We then finished up the previous lab writeups, which were handed in and graded over the break. Upon our return, we will begin the second half of the unit: the endocrine system.

AP Chem- we elaborated on the causes of ionic bonds in salts and hydroxide bases, polar covalent bonds in molecules, and nonpolar covalent bonds in molecules.
UNLIKE in covalent bonds, the strength of ionic bonds is SOLELY and COMPLETELY determined by the CHARGE DENSITY (charge AND size) of the cations and anions; ionic bonding has NOTHING to do with electronegativity or even Zeff on electrons because electrons are NOT shared in these bonds!
In covalent bonding, the degree of polarity WITHIN/OF the BOND is SOLELY determined by the Zeff and OPEL's of the TWO atoms that SHARE the (bonding) electrons. If there is sufficient difference in Zeff, OPEL's, or both of these factors, the electrons will be unequally shared creating a bond DIPOLE i.e. a polar bond.
We then drew examples of each case.

Bio 6- we elaborated on the physical and chemical processes that occur in each part of the digestive system up to and including the small intestine.

Bio 7/8- we elaborated on the physical and chemical processes that occur in each part of the digestive system up to and including the small intestine.
We then finished up our perspiration lab writeup.

Putting icing on the cake of 2008, you all put in a stunningly good performance on one of the top 3 most significant exams in this course (because Bonding is the culmination of two important and sequential units: Atomic Structure and Periodicity- the how and why of Zeff, OPEL's, and Coulomb's Law!).

AP Chem- we had a major exam today on Bonding/Molecular Geometry; this topic is always covered on one or TWO part II questions on the AP exam in which you will be given a molecule or ion, asked to draw a Lewis structure, deduce the geometry and polarity (if it's a molecule), and discuss the bonding/hybridization of the central atom, and possibly, if there are "competing" resonance structures, the "formal"/fake charges on the atoms.
If you did well, we have yet another exam on molecular geometry as it applies to INTER-molecular forces of attraction (not bonding), so that bodes well for you.

Bio 6/7- we went into more detail about the digestive process, the structure and function of each organ, the enzymes, starting molecules and product molecules.
We handed in some past labs and almost finished up our discussion of the perspiration and antagonistic muscle groups labs.

Bio 8- we went into more detail about the digestive process, the structure and function of each organ, the enzymes, starting molecules and product molecules.

AP Chem- we discussed the strengths of bonds in terms of "average" bond enthalpies also known as "bond dissociation energies". We can use these values to estimate the change in enthalpy for a reaction between gaseous molecules.
We're not going to use any fancy formula for these problems; in THIS case, formulas lead to wrong algebraic signs and faulty calculation. We'll go this simple visual route by drawing out any and all reactant bonds that are broken (REQUIRING ENERGY (+)) and the draw out all product bonds that form (RELEASING ENERGY (-)). Just add up the values and you have the change in enthalpy for the reaction!
Note: do NOT count a double bond as two "single" bonds. Bond energies do NOT work that way obviously because sigma and pi bonds require DIFFERENT amounts of energy to break.
DO as many problems as possible for tomorrow's exam. That is really the only way to prepare for exams in general in this course. Fortunately, there are lots of problems to practice with and with which you can check your answers!

Bio 6- we introduced the unit on nutrition/the digestive system by going step-by-step through a video to look at the various structures and functions involved in the digestive system; this system is essential for you to break down the complex molecules in food so that they can be absorbed (mostly via diffusion) into your body's cells.

Bio 7/8 -we introduced the unit on nutrition/the digestive system by going step-by-step through a video to look at the various structures and functions involved in the digestive system; this system is essential for you to break down the complex molecules in food so that they can be absorbed (mostly via diffusion) into your body's cells.
We then did a simulated perspiration lab to see the faster cooling effect caused by sweating.

AP Chem- we reviewed the comprehensive Lewis--General Formula--Orbital Hybridization--Electron Geometry--Molecular Geometry--Molecular Polarity chart and saw the overall connections that we can make between each pair of columns in order to affirm our answer to a given problem.
We then discussed the polarity of covalent bonds in terms of Zeff, OPEL's, and/or electronegativity differences. We then introduced the trivial concept of "CHARACTER", that is, the lower the electronegativity difference between two bonded elements, the more covalent the "character" of the bond whether it is ionic or covalent by definition. The greater the electronegativity difference between the two bonded elements, the more ionic the "character" of the bond.

We briefly discussed average bond enthalpy, which we will finish tomorrow before some review (come to class with questions ready- do some of the online practice tests/worksheets FIRST).
I will not be covering ionic compound lattice energy tomorrow so I will not be testing that in this class on Friday's exam. Lattice energy will be discussed before the next exam, though.

Bio- we had our Muscle/Bones/Skin exam today; for the double period, we discussed the perspiration lab.

AP Chem- Note: the following hw questions were not yet covered in class and thus will not be graded tomorrow- 40a, 40d, 40f, 42, and 47.
Also, we will have a 5 to 10 minute descriptive chemistry quiz in which you will write and balance the NET IONIC equation (though you may first write the formula equation as I did in the practice worksheet) and name each of four different reactions that we have covered over the past three months: a gas-forming reaction, a double-replacement with precipitation, an acid-base neutralization, and either a redox combustion or a redox single replacement (anionic or cationic).
An EASY way to practice is for you to make up your own reactions; if you truly take to heart the fact that most members of a given group chemically react/behave the same, all acids and bases react to form a salt and water, all metals will be oxidized to their most stable cations by aqueous solutions of copper II ions, silver ions, or gold ions then you can write out many different reactions already. If you know your solubility rules, you can think up hundreds of double-replacement reactions. Try it and ask me if you're not sure about what you've made up.

Today, we (finally) finished our extensive Lewis Structure/Electron Geometry/Central Atom Hybridization/Molecular Geometry/Molecular Polarity Chart!
I posted a METRIC TON of practice worksheets with which you can apply your new-found talent. Do them and check your answers so that you can ace Friday's exam with EASE (it's been done consistently in recent times though this test is no joke)!

We stepped back to our review of the types of bonding WITHIN a molecule or WITHIN a polyatomic ion and also the bonding BETWEEN/AMONG IONS in a LATTICE of an ionic compound (salt or hydroxide base). We also discussed the unnecessarily confusing concept of ionic CHARACTER and covalent CHARACTER of a given bond; we will elaborate further.

Bio 6- HW Objective Answers are posted; check them vs. your answers as part of your study for tomorrow's exam. I also posted information from our two lab discussions.

Today we finished the unit by summarizing the types of diseases of the integumentary and skeleto-muscular systems. We then discussed/reviewed proper scientific method/experimental design to test a hypothesis regarding muscle groups and muscle fatigue as well as our perspiration simulation lab.

Bio 7/8- HW Objective Answers are posted; check them vs. your answers as part of your study for tomorrow's exam. I also posted information from our two lab discussions.

Today we finished the unit by discussing skin functions, connective tissue and by summarizing the types of diseases of the integumentary and skeleto-muscular systems. We then discussed/reviewed proper scientific method/experimental design to test a hypothesis regarding muscle groups and muscle fatigue. We briefly discussed a perspiration lab; the graph and sample data from that lab are posted.

AP Chem- CHECK OUT the two descriptive chem sets (with answers) on Blackboard...very good practice for Wednesday's "replacement" quiz...double entendre intended!

We clarified previous general molecule/ion structures: AX2, AX3, and AX2E by showing that the proper Lewis structure SHOWS you the number of "electron DOMAINS/REGIONS" around the CENTRAL ATOM.
That, BY ITSELF, tells you BOTH the number of hybrid orbitals required AND the electronic geometry around the central atom. So getting the Lewis structure (starting with the valence electron counting, etc.) right is KEY to all subsequent steps.

We covered AX4, AX3E, AX2E2, AX5, AX4E, AX3E2, AX2E3, and AX6. We then did a lab simulation to help you visualize in 3-D the bond angles and the electronic and molecular geometries. Only the FIVE-electron-domain cases have more than one bond angle that is significantly different from the others (120 and 90 degrees for equatorial - equatorial and equatorial - axial, respectively).
We also saw that lone pairs of electrons repel bonding pairs of electrons farther away than do other bonding pairs of electrons.

Bio 6/7- it's official: the unit test is this Wednesday, DECEMBER 17th. Sorry that I didn't have the correct date before this weekend.
I'll collect the objectives tomorrow anyway (you may want to make a copy for yourself) and I'll post my answers on Blackboard tomorrow, also.
Bring in your photo/respiration test tomorrow so that we can go over some test skills that you can apply to the upcoming test.
We discussed the various functions of skin, specifically the structures of each of the three layers that comprise/make up skin and the function of each structure. Regulation of temperature, immune regulation, general protection against environmental chemicals and heat are some of the functions that we discussed.
We discussed a "negative BIOFEEDBACK" loop in which a person is caused to sweat when s/he is too hot, which then triggers cooling and a negative signal so that sweating stops when temperature homeostasis is reached (otherwise you would get too cold).
We did a lab that that tested the effect of sweating/water on the "skin" of the test tube (INDEPENDENT VARIABLE) on the rate of temperature decrease/cooling (the DEPENDENT VARIABLE i.e. what was being measured!).
We will do an antagonistic muscle pair lab tomorrow.

Bio 8- it's official: the unit test is this Wednesday, DECEMBER 17th. Sorry that I didn't have the correct date before this weekend.
I'll collect the objectives tomorrow anyway (you may want to make a copy for yourself) and I'll post my answers on Blackboard tomorrow, also.
Bring in your photo/respiration test tomorrow so that we can go over some test skills that you can apply to the upcoming test.
We discussed the various functions of skin, specifically the structures of each of the three layers that comprise/make up skin and the function of each structure. Regulation of temperature, immune regulation, general protection against environmental chemicals and heat are some of the functions that we discussed.
We did a lab that that tested the effect of sweating/water on the "skin" of the test tube (INDEPENDENT VARIABLE) on the rate of temperature decrease/cooling (the DEPENDENT VARIABLE i.e. what was being measured!).
We will do an antagonistic muscle pair lab tomorrow.

AP Chem- I will post the specific HW problems that you can handle so far; do not attempt the others yet. If we do not cover certain questions by test time, those questions will not be tested/graded on the hw. I will also post some videos/tutorials/solved problems. Check them.

We reviewed the basis and details of our electronic and molecular geometry chart, noting that the Lewis Structure will determine what general formula (AX2 or AX2E or AX4 etc.) to use.

We then covered the case of AX2E, which generally will involve resonance structures. Resonance structures in Lewis representations are more accurately seen as DELOCALIZED PI bonding in our orbital diagrams and pictures. In SO2, there are two p/pi electrons shared evenly among the three nuclei, which creates some extra stabilization (more than in just a single LOCAL pi bond).

DO NOT WORRY ABOUT THE HYBRIDIZATION OR lack of hybridization of the TERMINAL ATOMS! You cannot/will not be asked for such information because it cannot consistently be determined or is not even necessary in order to explain the experimental evidence on molecular geometry.

Now that we have delocalized pi bonding done, the rest of the chart can be completed much more quickly.

Bio 6- we discussed the three general types of muscle tissue: compared and contrasted them in terms of voluntary or involuntary, striated/striped vs. non-striated, and noted the main location(s) of each type of muscle tissue.
We then began to look at the integumentary system/the skin. We will further discuss the structure and function of each layer of tissue that makes up the skin organ.

Bio 7/8- we discussed the various diseases/injuries of joints and tendons: arthritis, tendonitis, and gout; then we talked about the three general types of muscle tissue: compared and contrasted them in terms of voluntary or involuntary, striated/striped vs. non-striated, and noted the main location(s) of each type of muscle tissue.
We then began to look at the integumentary system/the skin. We will further discuss the structure and function of each layer of tissue that makes up the skin organ.

AP Chem- we began the massive undertaking of learning all of the possible classic molecular (and polyatomic ion) geometries along with the "orbital hybridization" of the CENTRAL ATOM in each case. Though we also looked at the terminal atom orbitals involved in the bonds, generally it will suffice to know the CENTRAL ATOM hybridization so, good times.
Before we started the great chart, we looked at further exceptions to the octet rule in "electron deficient" compounds of H, B, and Be, which are stable with 2, 4, and 6 valence electrons in their molecules. You will see that Boron, in its compounds, is generally a good electron pair acceptor (because it still CAN, but doesn't HAVE TO, form another covalent bond), which makes it a good "Lewis acid".

Bio 6/7- We discussed the three functions of cartilage and then we discussed that muscle groups come in antagonistic pairs of flexors and extensors. We looked at the difference between ligaments (bone to bone, elastic) and tendons (muscle to bone, not elastic). We discussed tendonitis and arthritis, two diseases/injuries to the skeleto-muscular system.
We finished up our respiration/photosynthesis labs.

Bio 8- We discussed the three functions of cartilage and then we discussed that muscle groups come in antagonistic pairs of flexors and extensors. We looked at the difference between ligaments (bone to bone, elastic) and tendons (muscle to bone, not elastic).

AP Chem -we covered Lewis Structures of molecules that have "expanded octets" due to their available (hybridized) "d" orbitals enabling bonding of more than 8 electrons.
We also covered "odd-electron" molecules and saw that the central atom typically gets CLOSE to an octet: 7 valence electrons.
We discussed the relatively high reactivity of odd-electron "radical" molecules and saw an example of that: smog. On cool days, equilibrium favors the bonding of brown nitrogen dioxide molecules to form colorless dinitrogen tetroxide molecules.

Bio 6- We began our new unit on regulation via LOCOMOTION. We discussed the adaptive purposes of locomotion and the structures that simple and complex organisms have for that process. We discussed the various functions of bones/skeletons and then looked at various bone joints.

Bio 7/8- We began our new unit on regulation via LOCOMOTION. We discussed the adaptive purposes of locomotion and the structures that simple and complex organisms have for that process. We discussed the various functions of bones/skeletons and then looked at various bone joints.
We then almost finished the discussion of our past two labs, which will be finished and collected on Thursday.

AP Chem- we drew several Lewis structures involving resonance structures. ONLY the double bond or triple bond locations vary among resonance structures, NEVER the placement of atoms.

We discussed the relative lengths and strengths of single, double, and triple bonds seeing that the greater the number/order of the bond, the greater its strength and the SHORTER its length because, when there are more pairs of shared electrons between TWO positive nuclei, there is BY FAR much more net attraction.
We saw that actual bond order of a molecule that has resonance structures is a weighted average of all of its resonance structures i.e. the average bond order in nitrate ion is 4/3 because there are 4 pairs of electrons shared among 3 pairs of positive nuclei. A 4/3 bond is stronger and shorter than a single bond but weaker and longer than a double bond.

We discussed the "game" of formal charge, which is in no way, shape, or form real Coulombic charge. It is just a game invented by some chemists (and the game usually "works") to help decide the more and the less significant resonance structures in molecules that have several possible resonance structures.

We learned the Kaplan shortcut (saves SO much time and annoyance) for getting the formal charge of an atom in a resonance structure simply by drawing a circle around the atom and halfway through any bonds that it forms.

We applied the formal charge game and , most importantly, used it with REAL spectroscopic data to rationalize the best Lewis structure according to bond length and bond order.

We discussed our precipitation lab a bit more... we will continue that by writing out the net ionic equations that occurred during the analytical procedure.

Bio 6-8: we had the Cellular Respiration, Photosynthesis, and Plant Structures exam. Those who carefully followed the test-taking/test skills advice scored big-time again. Those who continue to not bother with these simple techniques lost many points due to careless errors and answered questions that were not there or used pronouns that referred to nothing or wrote incorrect information where a labelled picture would have sufficed.

Please, sir, may I have some more?
Oh all right ...just posted another photosynthesis and respiration practice test with "scientific method" application questions. The answer key is included, of course.
Reminder: there is extra help on Monday morning at 8AM in Room 308.

Answers to the Lewis Structure worksheet are now posted; check your work before class on Monday.

AP Chem- we've entered the glorious Bonding and IMFA Unit, the culmination of the Atomic Structure and Periodicity units. Now, we'll actually be able to logically DO/infer something with all of that Zeff and OPEL knowledge (without which, this unit is a bunch of random, arbitrary coincidences...good luck with all that).
:)
Today, we learned the concrete skill of drawing PROPER/CORRECT Lewis Structures for molecules and ions. This fundamental skill will allow us to see and then predict molecular structures/geometry, molecular polarity, and the types of intermolecular attractions for any given molecule. Suffice is to say that knowing how to draw these structures quickly EVERY time is crucial to success in understanding this unit.
I will post some Lewis structure problems with answers and, if I have time, a video podcast (I'm thinking of adding some cool intro music to these podcasts (don't we have a guitar player amongst us?).

Bio 6- we saw and discussed the results of yesterday's photosynthesis and alcoholic fermentation lab. For those who made hw mistakes, download the notes from Blackboard and seriously read or copy them until you find all of the hw answers.
Here are the answers to the objectives that were not graded:
19. Carbon "fixation" is the photosynthesis process in which Carbon in carbon dioxide, via a series of enzyme-controlled reactions, is BONDED/FIXED to other carbon, hydrogen, and oxygen atoms to form molecules of GLUCOSE, C6H12O6.

21. The pH (do not EVER use capital "p" or small "h" for pH!!! That is so wrong.) of water that contains aerobic organisms will DECREASE/become more ACIDIC because aerobic organisms always produce CARBON DIOXIDE from the respiration. SOME of the carbon dioxide dissolves and reacts with water to form CARBONIC ACID, which lowers the pH of the solution! (Notice that the BTB indicator turned YELLOW when YOU (an aerobic organism) breathed your CO2 into the BTB-containing water due to the carbonic acid that formed!

22. Elodea use the CARBON DIOXIDE that you breathed into the water (some CO2 is always dissolved in pond water where Elodea grow). The Elodea, when exposed to LIGHT, will then perform photosynthesis, using up the CARBON DIOXIDE and producing OXYGEN gas when it uses the light (and its enzymes) to SPLIT water into hydrogen and oxygen!


I've also posted the several practice tests with answer keys so you can prepare until you are super-confident about Monday's exam; do not wait until Monday's extra help session-
HOW and WHY questions get first priority at all review sessions because they are most important in understanding biology.


Bio 7/8- we saw and discussed the results of yesterday's photosynthesis lab. We then did the alcoholic fermentation lab and briefly discussed the final results at the end of class (see Blackboard for the notes).
For those who made hw mistakes, download the notes from Blackboard and seriously read or copy them until you find all of the hw answers.
Here are the answers to the objectives that were not graded:
19. Carbon "fixation" is the photosynthesis process in which Carbon in carbon dioxide, via a series of enzyme-controlled reactions, is BONDED/FIXED to other carbon, hydrogen, and oxygen atoms to form molecules of GLUCOSE, C6H12O6.

21. The pH (do not EVER use capital "p" or small "h" for pH!!! That is so wrong.) of water that contains aerobic organisms will DECREASE/become more ACIDIC because aerobic organisms always produce CARBON DIOXIDE from the respiration. SOME of the carbon dioxide dissolves and reacts with water to form CARBONIC ACID, which lowers the pH of the solution! (Notice that the BTB indicator turned YELLOW when YOU (an aerobic organism) breathed your CO2 into the BTB-containing water due to the carbonic acid that formed!

22. Elodea use the CARBON DIOXIDE that you breathed into the water (some CO2 is always dissolved in pond water where Elodea grow). The Elodea, when exposed to LIGHT, will then perform photosynthesis, using up the CARBON DIOXIDE and producing OXYGEN gas when it uses the light (and its enzymes) to SPLIT water into hydrogen and oxygen!


I've also posted the several practice tests with answer keys so you can prepare until you are super-confident about Monday's exam; do not wait until Monday's extra help session-
HOW and WHY questions get first priority at all review sessions because they are most important in understanding biology.

AP Chem- took the Thermochemistry Unit Exam, which also included a descriptive chemistry set. We will finish the rest of Thermodynamics i.e. Entropy and Gibbs Free Energy when we do the penultimate unit in our course (in April!).
All units from here on in are more challenging and more heavily tested on the AP exam.
Tomorrow, we begin the Bonding Unit, the second-longest unit in the course and the MOST important unit in qualitatively understanding chemistry. The bonding unit is the logical extension of the two units on atomic/electronic structure and periodicity. Now that you know Zeff and OPEL's, you will be applying that knowledge to every single conceivable bonding or intermolecular attraction phenomenon.
Understanding of the bonding and intermolecular attraction unit, per se, means that you truly understand chemistry.

Bio 6/7- we started two experiments today: one was on photosynthesis and noting changes that occur in a carbon dioxide saturated solution when plants are placed in light; the other experiment involved observing changes in solution due to the anaerobic/alcoholic fermentation of sugar by yeast cells. We will view and explain the results of the experiment, tomorrow.

Bio 8-we started one of two experiments today: one was on photosynthesis and noting changes that occur in a carbon dioxide saturated solution when plants are placed in light; the other experiment, which we will do tomorrow, involved observing changes in solution due to the anaerobic/alcoholic fermentation of sugar by yeast cells. We will view and explain the results of the experiment, tomorrow.

AP Chem- we covered (and you really should use them) Thermo test-taking tips: make sure that you carefully IDENTIFY and LABEL, directly in the question, all data and relate/LABEL those values so that you can directly plug them into the thermo formula. Draw a picture so that you can SEE where the energy (heat) is flowing AND whether any WORK is being done by GASES.

We then reviewed some of descriptive chem reactions and started to expand our repertoire by considering cationic and anionic single replacement redox reactions.

There are an insane number of practice problems online for tomorrow's test. You will see very similar problems, naturally, on tomorrow's exam so try to do as many practice problems as you can; be very meticulous/fastidious and check your work.

Bio 6- We are done with the unit objectives except for #'s 19, 21, and 22 (so those will not be graded on your HW) that involve lab work; therefore, we will be doingmostly lab work for the next THREE class periods. Get ready for labs that WORK.
We discussed the connection between the potential SIZE of an organism and its ability to extract energy from glucose aerobically or anaerobically.
We then did a BIG PICTURE connection between photosynthesis and cellular respiration, showing the relationship between the products of photosynthesis (glucose and oxygen) and the reactants of aerobic respiration (glucose and oxygen!) and vice versa.

Bio 7/8- We are done with the unit objectives except for #'s 19, 21, and 22 (so those will not be graded on your HW) that involve lab work; therefore, we will be doing mostly lab work for the next THREE class periods. Get ready for labs that WORK.
We discussed the connection between the potential SIZE of an organism and its ability to extract energy from glucose aerobically or anaerobically.
We then did a BIG PICTURE connection between photosynthesis and cellular respiration, showing the relationship between the products of photosynthesis (glucose and oxygen) and the reactants of aerobic respiration (glucose and oxygen!) and vice versa.

We discussed the "rate of photosynthesis" lab in which we measured the rate of photolysis, which is the first step of photosynthesis in which light energy is absorbed by the chlorophylls in the chloroplast and some of that energy is used to "split" water into hydrogen and oxygen. The oxygen gas then diffuses from the plant cell and out of the plant, which we saw bubbling through the water in the test tube. We saw that, as we increased the light intensity (decreased distance between plant and light source!) and also as we increased the concentration of CO2 in the plant's surroundings (by adding sodium CARBONate), we increased the rate of photolysis and photosynthesis!

AP Chem- I just posted a MASSIVE thermochem practice exam that also has a detailed answer key. You can't go wrong if you take this test and correct your errors before Thursday. In addition, I posted a file that contains 5 Thermochem practice worksheets with a basic answer key.

Today, we did a Hess Law question using both methods of solution. We then enhanced the problem with a limiting reactant stoichiometry part as well as a calorimetry and a change in internal energy part.
We will move on to our new unit tomorrow and have our Thermo unit exam on Thursday. MAKE SURE that you know AND understand all thermochemistry units, definitions, algebraic SIGNS, etc.; the ONLY way to be sure that you understand and can apply these items is to DO/SOLVE problems involving them.

Bio 6/7- UNIT EXAM IS ON MONDAY. HW OBJECTIVES ARE DUE ON THURSDAY.
We FURTHER reviewed and clarified the steps involved in ANaerobic respiration/fermentation (both alcoholic and lactic acid types); the first step of breaking bonds in glucose REQUIRES 2 ATP for energy but that reaction, which forms two pyruvic acid molecules, generates 4 ATP molecules for a net GAIN of 2 ATP! For both fermentation types, there is a required SECOND step involving different enzymes that convert pyruvic acid into either alcohol and carbon dioxide OR into lactic acid but NO more ATP (as we discussed just FYI, this last step is necessary to regenerate the NAD+ that is needed for more glucose molecules to be broken down).
We then looked at the three-part process of AEROBIC respiration. The first step, in the cytosol/cytoplasm, is just regular glycolysis, which NETS 2 ATP and 2 pyruvic acid molecules from 1 glucose. The pyruvic acid molecules are Actively TransPorted INTO the mitochondria, where they will be partially broken down into carbon dioxide (which diffuses from the cell and is eventually transported to the lungs via your blood and then breathed out); then the resulting molecules are further broken down in the ELECTRON TRANSPORT CHAIN by reacting with OXYGEN to form water and carbon dioxide. These two processes NET 34 more ATP for a total of 36 ATP per one molecule of glucose aerobically respired! That is a much more complete/efficient energy extraction from glucose than is done via fermentation!

We then almost finished our rate of photosynthesis discussion; we will finish that before our respiration lab on Thursday.

Bio 8- UNIT EXAM IS ON MONDAY. HW OBJECTIVES ARE DUE ON THURSDAY.
We FURTHER reviewed and clarified the steps involved in ANaerobic respiration/fermentation (both alcoholic and lactic acid types); the first step of breaking bonds in glucose REQUIRES 2 ATP for energy but that reaction, which forms two pyruvic acid molecules, generates 4 ATP molecules for a net GAIN of 2 ATP! For both fermentation types, there is a required SECOND step involving different enzymes that convert pyruvic acid into either alcohol and carbon dioxide OR into lactic acid but NO more ATP (as we discussed just FYI, this last step is necessary to regenerate the NAD+ that is needed for more glucose molecules to be broken down).
We then looked at the three-part process of AEROBIC respiration. The first step, in the cytosol/cytoplasm, is just regular glycolysis, which NETS 2 ATP and 2 pyruvic acid molecules from 1 glucose. The pyruvic acid molecules are Actively TransPorted INTO the mitochondria, where they will be partially broken down into carbon dioxide (which diffuses from the cell and is eventually transported to the lungs via your blood and then breathed out); then the resulting molecules are further broken down in the ELECTRON TRANSPORT CHAIN by reacting with OXYGEN to form water and carbon dioxide. These two processes NET 34 more ATP for a total of 36 ATP per one molecule of glucose aerobically respired! That is a much more complete/efficient energy extraction from glucose than is done via fermentation!

Welcome back from Thanksgiving Vacation! Thanks for getting right back into action.

AP Chem- we discussed general strategies for the two permutations of Hess Law problems and then we applied a strategy to a sample problem.
We reviewed the meaning of a "heat of formation" reaction in which you MUST form only ONE mole of the desired product from ITS elements in their MOST stable form under standard conditions.
We then used the energy change calculated from the earlier part of the question to determine what temperature change that would be expected in a calorimeter containing a given quantity of water.
Remember, sometimes the calorimeter heat capacity will be given separate from its contents (usually water is the energy absorbing material) so you will have to ADD the energy absorbed by the calorimeter ( C x delta T ) TO the energy absorbed by the water in the calorimeter
( m x c x delta T) and set that sum equal to (but opposite in sign) the energy released by the (reacting) system.

Bio 6- we continued with our second half of the unit: Cellular Respiration.
We discussed the two general types of respiration, aerobic (uses oxygen) and anaerobic (no oxygen used).
We then looked at the TWO types of ANaerobic respiration: alcoholic fermentation and lactic acid fermentation. Both of these types of anaerobic respiration only produce/yield/net/form 2 ATP molecules per molecule of glucose that is fermented.
We saw that each of these enzyme-mediated processes starts with glucose being broken/hydrolyzed into two three-carbon pyruvic acid molecules; it is during this step that a net of 2 ATP (energy-containing) molecules are formed.
In alcoholic fermentation, the pyruvic acid is further broken down (with the aid of specific enzymes) to ethanol and carbon dioxide without the production of any more ATP- we saw that the purpose of this step: to regenerate NAD+ so that the next glucose molecule can undergo glycolysis.
In lactic acid fermentation, the pyruvic acid is converted to a different 3-carbon molecule (lactic acid) without the production of any more ATP. Again, this step is necessary in order toregenerate NAD+ so that the next glucose molecule can undergo glycolysis.

Tomorrow, we will focus on AEROBIC cellular respiration.

Bio 7/8- we continued with our second half of the unit: Cellular Respiration.
We discussed the two general types of respiration, aerobic (uses oxygen) and anaerobic (no oxygen used).
We then looked at the TWO types of ANaerobic respiration: alcoholic fermentation and lactic acid fermentation. Both of these types of anaerobic respiration only produce/yield/net/form 2 ATP molecules per molecule of glucose that is fermented.
We saw that each of these enzyme-mediated processes starts with glucose being broken/hydrolyzed into two three-carbon pyruvic acid molecules; it is during this step that a net of 2 ATP (energy-containing) molecules are formed.
In alcoholic fermentation, the pyruvic acid is further broken down (with the aid of specific enzymes) to ethanol and carbon dioxide without the production of any more ATP- we saw that the purpose of this step: to regenerate NAD+ so that the next glucose molecule can undergo glycolysis.
In lactic acid fermentation, the pyruvic acid is converted to a different 3-carbon molecule (lactic acid) without the production of any more ATP. Again, this step is necessary in order to regenerate NAD+ so that the next glucose molecule can undergo glycolysis.

We began our discussion of AEROBIC cellular respiration, which we will continue with tomorrow.

We then tried to complete our (troublesome) factors that affect the rate of photosynthesis lab.
We will discuss this and wrap it up on Wednesday before we do a different lab.