Monday, September 26, 2011
Mon-Day 1
AP Chem - here is a list of questions by topic that will be covered on your moles and stoichiometry I exam:
1. Determining the percent abundance of two known isotopes of an element, given their isotope masses, and the atomic mass of the element (or getting the atomic mass of an element from the given isotope masses and their percent abundances).
2. Converting any size sample of any substance from grams to moles to number of particles or, for an ideally behaving gas, converting from volume to moles or vice-versa at a given temperature and pressure (the value of R is in the reference tables) ...i.e. using the AP Magic Triangle.
3. Determining the percent composition by mass of the elements in any compound or of water in a hydrate.
4. Using the information in 3. to determine the mass of a given element in a given size/mass of a sample of a compound or to determine the remaining mass of an anhydrate or the mass of water that would be lost from a given mass sample of a hydrate.
5. Determining the empirical formula of a compound or the formula of a hydrate from percent composition data or from raw mass data.
6. Determining the atomic mass of an unknown element in a compound via gravimetric analysis.
7. Determining the empirical formula of a compound via combustion analysis.
8. Determining the molecular formula of a compound given it molar mass , and its previously determined empirical formula.
9. Balancing a chemical equation, and using that equation and given masses of reactants to determine the limiting reactant, and masses of each product, and the mass of excess reactant that remains after the reaction has gone to completion.
10. Given an actual product yield, using the information in 9. to determine the percent yield of the product.
For this exam, I will leave off equation writing i.e. double replacement with precipitation predictions, as well as law of multiple proportion calculations.
STUDY WELL - that means doing MANY problems without EVER leaving out a UNIT or the SUBSTANCE to which the UNIT refers!!! Do not miss this test on Wednesday.
Bio - we reviewed the four major organic biological molecules: carbohydrates, lipids, proteins, and nucleic acids. We then focused on proteins, which have the greatest variety of structures and "jobs"/functions due to the fact that they are made up of up to 20 different amino acids in specific sequences that are between 50 to over 1000 amino acids long!We focused on the effect of temperature on an enzyme: at low temperatures, the enzyme retains its natural 3-D shape so that it can speed up the reaction of the substrate molecule(s) when it collides with and binds them; at low temperatures, though, this collision rate is low so the overall enzyme activity rate is low.
We saw the similarities and differences among the 20 amino acids and noted that the "side chains" of the amino acids cause the protein to "fold" or morph into a particular shape. A protein's specific shape gives it a specific function.
we discussed the various functions of proteins: enzymes speed up the rate of reactions by positioning substrate molecules properly for bond breakage (hydrolysis) or formation (synthesis),
transport proteins carry needed molecules or even wastes to other parts of the body, hormones help signal "target cells" to regulate the various other life functions in the body, antibodies are the main proteins of the immune/defense response of the body; antibodies bind to foreign organisms' surface proteins and immobilize/mark for death the pathogen, motor proteins are capable of sliding over each other causing muscle contraction and other motions.
We then focused on enzymes, showing that they work to hydrolyze or synthesize particular substrates based on the specific complementary shape of the substrate and enzyme.
We then noted that proteins can only maintain their ideal shape in environments of a particular acidity; otherwise, the amino acid chain unravels/"denatures" and the protein loses its shape and can no longer function.
As temperature increases, both enzyme and substrate molecules move faster and collide more frequently so the rate of enzyme activity increases.
However, beyond a given enzyme's optimum/optimal temperature, the enzyme moves too fast and collides with even greater forces causing it to unravel/denature and lose its shape and its active site.
1. Determining the percent abundance of two known isotopes of an element, given their isotope masses, and the atomic mass of the element (or getting the atomic mass of an element from the given isotope masses and their percent abundances).
2. Converting any size sample of any substance from grams to moles to number of particles or, for an ideally behaving gas, converting from volume to moles or vice-versa at a given temperature and pressure (the value of R is in the reference tables) ...i.e. using the AP Magic Triangle.
3. Determining the percent composition by mass of the elements in any compound or of water in a hydrate.
4. Using the information in 3. to determine the mass of a given element in a given size/mass of a sample of a compound or to determine the remaining mass of an anhydrate or the mass of water that would be lost from a given mass sample of a hydrate.
5. Determining the empirical formula of a compound or the formula of a hydrate from percent composition data or from raw mass data.
6. Determining the atomic mass of an unknown element in a compound via gravimetric analysis.
7. Determining the empirical formula of a compound via combustion analysis.
8. Determining the molecular formula of a compound given it molar mass , and its previously determined empirical formula.
9. Balancing a chemical equation, and using that equation and given masses of reactants to determine the limiting reactant, and masses of each product, and the mass of excess reactant that remains after the reaction has gone to completion.
10. Given an actual product yield, using the information in 9. to determine the percent yield of the product.
For this exam, I will leave off equation writing i.e. double replacement with precipitation predictions, as well as law of multiple proportion calculations.
STUDY WELL - that means doing MANY problems without EVER leaving out a UNIT or the SUBSTANCE to which the UNIT refers!!! Do not miss this test on Wednesday.
Bio - we reviewed the four major organic biological molecules: carbohydrates, lipids, proteins, and nucleic acids. We then focused on proteins, which have the greatest variety of structures and "jobs"/functions due to the fact that they are made up of up to 20 different amino acids in specific sequences that are between 50 to over 1000 amino acids long!We focused on the effect of temperature on an enzyme: at low temperatures, the enzyme retains its natural 3-D shape so that it can speed up the reaction of the substrate molecule(s) when it collides with and binds them; at low temperatures, though, this collision rate is low so the overall enzyme activity rate is low.
We saw the similarities and differences among the 20 amino acids and noted that the "side chains" of the amino acids cause the protein to "fold" or morph into a particular shape. A protein's specific shape gives it a specific function.
we discussed the various functions of proteins: enzymes speed up the rate of reactions by positioning substrate molecules properly for bond breakage (hydrolysis) or formation (synthesis),
transport proteins carry needed molecules or even wastes to other parts of the body, hormones help signal "target cells" to regulate the various other life functions in the body, antibodies are the main proteins of the immune/defense response of the body; antibodies bind to foreign organisms' surface proteins and immobilize/mark for death the pathogen, motor proteins are capable of sliding over each other causing muscle contraction and other motions.
We then focused on enzymes, showing that they work to hydrolyze or synthesize particular substrates based on the specific complementary shape of the substrate and enzyme.
We then noted that proteins can only maintain their ideal shape in environments of a particular acidity; otherwise, the amino acid chain unravels/"denatures" and the protein loses its shape and can no longer function.
As temperature increases, both enzyme and substrate molecules move faster and collide more frequently so the rate of enzyme activity increases.
However, beyond a given enzyme's optimum/optimal temperature, the enzyme moves too fast and collides with even greater forces causing it to unravel/denature and lose its shape and its active site.
# posted by C @ 2:55 PM 
