Download SI Worksheet 10 1. What does coupling reactions mean? The

SI Worksheet 10
1. What does coupling reactions mean?
The process of coupling reactions that are unfavorable with reactions that are favorable in order to
make them “go.”
2. What components make up an ATP molecule, what kind of molecule is ATP?
5-ring sugar
Adenine nucleotide
3 Phosphate Groups
Nucleic Acid
3. What does the Hydrolysis of ATP result in?
Water breaks ATP into ADP and Pi (inorganic phosphate)
4. What is the difference between anabolism and catabolism?
Anabolism is the building of something
Catabolism is the breaking down of something
5. All the chemistry going on in the human body is referred to as ______________.
Metabolism
6. In order to speed up reactions in cells in the human body, we use heat. T or F
False – Enzymes
7. What is an enzyme?
An enzyme is a biological catalyst. They usually end in the suffix “-ase.”
8. Enzymes speed up reactions by lowering the ∆G of a reaction. T or F
False – they lower the Activation Energy
9. Can you draw an endergonic or exergonic reaction graph? Can you draw a RXn graph in the
presence of enzymes compared to the absence of enzymes?
Exergonic = ∆G < 0
Endergonic Reaction = ∆G> 0
An enzymes presence would cause the EA to be lower.
10. Explain the mechanisms that underlie enzymes regarding the enzyme substrate theory? Is it
known as ”Lock and Key” or “Induced Fit Hypothesis”?
Substrates bind to an enzyme at a place known as the active site. Once the substrates have
bound to the active site the enzyme changes shape and caudles up to the substrates putting pressure
on the bonds. The enzyme releases the product after it has been formed. The lock and key is no
longer accepted, we now refer to enzymes as using the induced fit hypothesis.
11. What is saturation and how does it relate to enzymes and substrates?
Saturation is the point at which every enzyme is occupied with substrate. Remember the key is
to understand that at saturation adding more substrate will NOT increase the rate of the reaction….
Only adding more enzymes will increase the reaction rate.
12. Enzymes can facilitate both the dismantlement and assembly sugars. T or F
True – Enzymes can do reactions in BOTH directions
13. What are the 3 factors that can affect enzyme activity?
Temperature – denaturing of protein
pH – pepsin, trypsin
Salt Concentration – ions can alter the activity of enzymes
14. Another word for a non-protein organic molecule is ______________. What is an example of one?
Coenzymes, NAD+) “nicotinamide adenine dinucleotide”, they help enzymes do their thing
15. What is an important example of a cofactor in the body?
Mg 2+, most of the cofactors are metal ions that are important in transferring phosphates
16. Pepsinogen is the active form of Pepsin, what is the importance and the mechanism that
activates it from its inactive form to its active form?
HCl cleaves off 42 amino acids, thus, revealing the active site… now it is no longer a zymogen and
allowed to break down proteins in the stomach
17. Compare and contrast competitive and noncompetive inhibition.
Both inhibit the binding of substrates to enzymes.
Competitive inhibitors bind directly to the active site of enzymes therefore directly competing for
the active site
Noncompetitive inhibitors do not bind to the active sit but to somewhere else that ultimately
changes the shape of the active site which in turn does not allow the substrate to fit in the active site
18. Explain enzyme cooperativity.
Cooperativity is the process in which it is VERY hard for an enzyme to bind the first substrate,
however, after the first substrate has bound to the enzyme, the process of binding becomes much
easier for the next substrate that attempts to bind to the enzyme.
19. Redox reactions are key reactions in Cellular respiration. Explain oxidation and reduction.
OIL – oxidation is loss of electrons
RIG – reduction is gain of electrons