$$\text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2 \rightarrow 6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{energy}$$

Question 1

Which of the following best describes the difference between kinetic and potential energy in a biological system?

Accepted Answer

Kinetic energy is the energy of motion, while potential energy is stored energy, such as in chemical bonds.

Question 2

During cellular respiration, which molecule acts as the final electron acceptor in the electron transport chain (ETC)?

Accepted Answer

O$$_2$$

Question 3

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes speed up reactions by lowering the activation energy, but do not affect the overall change in free energy ($$\Delta G).$$

Question 4

Which of the following best describes the process of substrate-level phosphorylation?

Accepted Answer

ATP is produced directly by transferring a phosphate group from a substrate to ADP.

Question 5

A mutation causes a cell to produce a nonfunctional phosphatase enzyme. Which of the following is a likely consequence?

Accepted Answer

Proteins will remain phosphorylated longer, potentially altering their activity.

Question 6

Which of the following equations correctly represents the overall reaction for aerobic cellular respiration?

Accepted Answer

$$	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6 	ext{O}_2 ightarrow 6 	ext{CO}_2 + 6 	ext{H}_2	ext{O} + 	ext{energy}$$

Question 7

Which of the following best explains why oxygen is required for aerobic respiration?

Accepted Answer

Oxygen acts as the final electron acceptor in the electron transport chain, allowing the chain to continue functioning.

Question 8

Which of the following statements about the light-dependent reactions of photosynthesis is correct?

Accepted Answer

They use water as an electron donor and produce O$$_2$$, ATP, and NADPH.

Question 9

A plant is exposed to light that is primarily green in wavelength. What is the most likely effect on the rate of photosynthesis, and why?

Accepted Answer

The rate will decrease because chlorophyll reflects green light, absorbing less energy for photosynthesis.

Question 10

Which of the following best describes the difference between C$$_3$$ and CAM plants in terms of carbon fixation?

Accepted Answer

CAM plants separate carbon fixation and the Calvin cycle by time, while C$$_3$$ plants do not separate them.

Question 11

Which of the following is true regarding the structure of DNA?

Accepted Answer

The two strands are antiparallel and held together by hydrogen bonds between complementary bases.

Question 12

Which of the following best explains the significance of Chargaff's rules for DNA structure?

Accepted Answer

They show that the amount of purines always equals the amount of pyrimidines, supporting base pairing.

Question 13

During DNA replication, which enzyme is responsible for synthesizing the new DNA strand by adding nucleotides to the 3' end?

Accepted Answer

DNA polymerase

Question 14

Which of the following best describes the role of NAD$$^+ in $$cellular respiration?

Accepted Answer

It acts as an electron carrier, accepting electrons during glycolysis and the Krebs cycle.

Question 15

A competitive inhibitor of an enzyme would most likely:

Accepted Answer

Bind to the active site, preventing the substrate from binding.

Question 16

Which of the following statements about feedback inhibition is correct?

Accepted Answer

The end product of a metabolic pathway inhibits the first enzyme in the pathway.

Question 17

Which of the following best explains why fermentation is less efficient than aerobic respiration?

Accepted Answer

Fermentation does not use the electron transport chain, so less ATP is produced per glucose.

Question 18

Which of the following is a correct summary of the energy yield from one molecule of glucose during aerobic respiration in eukaryotes?

Accepted Answer

2 ATP from glycolysis, 2 ATP from Krebs cycle, and about 28 ATP from oxidative phosphorylation, totaling about 32 ATP.

Question 19

Which of the following best describes the function of ATP synthase in the mitochondria?

Accepted Answer

It uses the flow of protons down their electrochemical gradient to synthesize ATP from ADP and $$P_i.$$

Question 20

Which of the following is true about the Calvin cycle in photosynthesis?

Accepted Answer

It fixes CO$$_2$$ into organic molecules using ATP and NADPH from the light-dependent reactions.

General Biology: Cellular Energy, Photosynthesis, and DNA Structure Study Notes

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