Review Questions

1.

Energy can be taken in as glucose, then has to be converted to a form that can be easily used to perform work in cells. What is the name of the latter molecule?

1. anabolic molecules
2. cholesterol
3. electrolytes
4. adenosine triphosphate

2.

When cellular respiration occurs, what is the primary molecule used to store the energy that is released?

1. AMP
2. ATP
3. mRNA
4. phosphate

3.

Which of the following is not involved in DNA replication?

1. Breaking down complex molecules into simpler molecules with a release of energy.
2. Unwinding two strands of parent DNA.
3. Copying each DNA strand to synthesize complimentary strands.
4. Releasing two semi-conserved strands of DNA.

4.

Which of the following is a catabolic process?

1. digestion of sucrose
2. dissolving sugar in water
3. DNA replication
4. RNA translation

5.

What food molecule, used by animals for energy and obtained from plants, is most directly related to the use of sun energy?

1. glucose
2. protein
3. triglycerides
4. tRNA

6.

What reaction will release the largest amount of energy to help power another reaction?

1. AMP to ATP
2. ATP to ADP
3. DNA to proteins
4. glucose to starch

7.

Consider a pendulum swinging. Which type(s) of energy is/are associated with the pendulum in the following instances:

1. the moment at which it completes one cycle, just before it begins to fall back towards the other end
2. the moment that it is in the middle between the two ends
3. just before it reaches the end of one cycle (before step 1)

1. 1. potential and kinetic
   2. potential and kinetic
   3. kinetic
2. 1. potential
   2. potential and kinetic
   3. potential and kinetic
3. 1. potential
   2. kinetic
   3. potential and kinetic
4. 1. potential and kinetic
   2. kinetic
   3. kinetic

8.

Which of the following best describes energy?

1. the transfer of genetic information
2. the ability to assemble a large number of functional catalysts
3. the ability to store solar output
4. something that all living systems require an input of

9.

What is the ultimate source of energy on this planet?

1. glucose
2. plants
3. metabolic pathways
4. the sun

10.

Which of the following molecules is likely to have the most potential energy?

1. ATP
2. ADP
3. glucose
4. sucrose

11.

Which of the following is the best way to judge the relative activation energies between two given chemical reactions?

1. Compare the Δ⁢𝐺 values between the two reactions.
2. Compare their reaction rates.
3. Compare their ideal environmental conditions.
4. Compare the spontaneity between the two reactions.

12.

Which of the terms in the Gibbs free energy equation denotes enthalpy?

1. Δ⁢𝐺
2. Δ⁢𝐻
3. Δ⁢𝑆
4. Δ⁢𝑇

13.

Which chemical reaction is more likely to occur?

1. dehydration synthesis
2. endergonic
3. endothermic
4. exergonic

14.

Which of the following comparisons or contrasts between endergonic and exergonic reactions is false?

1. All endergonic and exergonic reactions require the same amount of energy to overcome an activation barrier.
2. Endergonic reactions have a positive Δ⁢𝐺 and exergonic reactions have a negative Δ⁢𝐺.
3. Endergonic reactions consume energy and exergonic reactions release energy.
4. Endergonic reactions are not spontaneous and exergonic reactions are spontaneous.

15.

Label each of the following systems as high or low entropy:

1. perfume the instant after it is sprayed into the air
2. an unmaintained 1950s car compared with a brand new car
3. a living cell compared with a dead cell

1. 1. low
   2. high
   3. low
2. 1. low
   2. high
   3. high
3. 1. high
   2. low
   3. high
4. 1. high
   2. low
   3. low

16.

What makes a system more stable?

1. energy release
2. endergonic reactions
3. input of energy
4. time

17.

Which of the following is the best example of the first law of thermodynamics?

1. a body getting warmer after exercise
2. a piece of fruit spoiling in the fridge
3. a power plant burning coal and producing electricity
4. an exothermic chemical reaction

18.

What is the difference between the first and second laws of thermodynamics?

1. The first law involves creating energy while the second law involves expending it.
2. The first law involves expending energy while the second involves creating it.
3. The first law involves conserving energy while the second law involves the inability to recapture energy.
4. The first law discusses creating energy while the second law discusses the energy requirement for reactions.

19.

Which best describes the effect of inputting energy into a living system?

1. Energy input must exceed energy loss to maintain order and to power cellular processes.
2. It fuels metabolism.
3. Inputting energy into a living system leads to death.
4. The energy is used to produce carbohydrates.

20.

Refer to [link]

.

Why is ATP considered the energy currency of the cell?

1. It accepts energy from chemical reactions.
2. It holds energy at the site of release from substrates.
3. It is a protein.
4. It can transport energy to locations within the cell.

21.

What is ATP made from?

1. adenosine + high energy electrons
2. ADP + phosphate
3. AMP + ADP
4. the conversion of guanine to adenosine

22.

What is true about the energy released by the hydrolosis of ATP?

1. It is equal to −57 kJ/mol.
2. The cell harnesses it as heat energy in order to perform work.
3. It is primarily stored between the alpha and beta phosphates.
4. It provides energy to coupled reactions.

23.

What part of ATP is broken to release energy for use in chemical reactions?

1. the adenosine molecule
2. the bond between the first and second phosphates
3. the bond between the first phosphate and the adenosine molecule
4. the bond between the second and third phosphates

24.

An allosteric inhibitor does which of the following?

1. binds to an enzyme away from the active site and changes the conformation of the active site, increasing its affinity for substrate binding
2. binds to an active site and blocks it from binding substrate
3. binds to an enzyme away from the active site and changes the conformation of the active site, decreasing its affinity for the substrate
4. binds directly to the active site and mimics the substrate

25.

What happens if an enzyme is not functioning in a chemical reaction in a living organism that needs it?

1. The reaction stops.
2. The reaction proceeds, but much more slowly.
3. The reaction proceeds faster without the interference.
4. There is no change in the reaction rate.

26.

Which of the following is not true about enzymes?

1. They are consumed by the reactions they catalyze.
2. They are usually made of amino acids.
3. They lower the activation energy of chemical reactions.
4. Each one is specific to the particular substrate, or substrates, to which it binds.

27.

Which of the following analogies best describe the induced-fit model of enzyme-substrate binding?

1. a hug between two people
2. a key fitting into a lock
3. a square peg fitting through the square hole and a round peg fitting through the round hole of a children’s toy
4. the fitting together of two jigsaw puzzle pieces

28.

What is the function of enzymes?

1. to increase the free energy of reactions
2. to increase the the sum of the heats of formation
3. to lower the randomness of the chemicals in the reaction
4. to lower the activation energy of a reaction