*The Less Stable You Are, the Higher Free Energy You Have (More Energy to Do Work)

BY 123 SI Session 10/05/15

*The less stable you are, the higher free energy you have (more energy to do work)!!

Chapter 8 Questions

1. Which of the following metabolic processes can occur without a net influx of energy from some other process?

A) ADP + Pi → ATP + H2O

B) C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

C) 6 CO2 + 6 H2O → C6H12O6 + 6 O2

D) amino acids → protein

E) glucose + fructose → sucrose

2. According to the first law of thermodynamics,

A) matter can be neither created nor destroyed.

B) energy is conserved in all processes.

C) all processes increase the disorder of the universe.

D) systems rich in energy are intrinsically stable.

E) the universe constantly loses energy because of friction.

3. Choose the pair of terms that correctly completes this sentence:

Catabolism is to anabolism as ______is to ______.

A) exergonic; spontaneous

B) exergonic; endergonic

C) free energy; entropy

D) work; energy

E) entropy; enthalpy

4. Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

A) Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time.

B) Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is balanced by an increase in the entropy of the universe.

C) Living organisms do not follow the laws of thermodynamics.

D) As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth.

E) Living organisms are able to transform energy into entropy.

Relate concept of entropy to sugar dissolving in a cup of water then reappearing later when water evaporates.

5. Which of the following reactions is most likely to be coupled to the reaction ATP + H2O →ADP + Pi (ΔG = -7.3 kcal/mol)?

A) A + Pi → AP (ΔG = +10 kcal/mol)

B) B + Pi → BP (ΔG = +8 kcal/mol)

C) CP → C + Pi (ΔG = -4 kcal/mol)

D) DP → D + Pi (ΔG = -10 kcal/mol)

E) E + Pi → EP (ΔG = +5 kcal/mol)

Key thing to note: thermal energy (heat) cannot really be harnessed to do cellular work.

6. What would decrease the entropy?

A) dehydration reaction

B) respiration

C) working out in the gym

D) catabolism

E) cutting the grass

7. What is an enzyme? Is it consumed in the reaction? How does it quicken a reaction? Why do we still need enzymes for catabolic or exergonic reactions if they are spontaneous?

8. What’s the activation energy of a reaction?

9. Why is addition of heat inappropriate for biological systems?

T/F Enzymes occasionally change the free energy of reactions.

10. What’s the structure called when an enzyme binds to its substrate?

11. What accounts for enzymes’ high specificities?

12. Where does the substrate bind?

13. Can the enzyme change shapes?

14. Know the ways the active site can speed up a reaction.

15. Discuss effects of temperature and pH on these enzymes.

16. What are cofactors? Coenzymes? Which ones should you know?

What are inactive enzymes called?

17. Compare and contrast competitive and noncompetitive inhibitors.