Q: Which of the following equations correctly represents the overall process of photosynthesis?

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

Question 1

Which of the following statements best describes the role of oxygen in cellular respiration?

Accepted Answer

Oxygen acts as the final electron acceptor in the electron transport chain, allowing for the formation of water.

Question 2

During glycolysis, what is the net gain of ATP and NADH molecules per molecule of glucose?

Accepted Answer

$$2$$ ATP and $$2$$ NADH

Question 3

A patient’s muscle cells are deprived of oxygen during intense exercise. Which process allows these cells to continue producing ATP, and what is the main byproduct?

Accepted Answer

Lactic acid fermentation; lactic acid

Question 4

Which of the following best explains why fats yield more ATP per gram than carbohydrates during cellular respiration?

Accepted Answer

Fats have more hydrogen atoms, providing more high-energy electrons for the electron transport chain.

Question 5

Which of the following equations correctly represents the overall process of photosynthesis?

Accepted Answer

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

Question 6

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

Accepted Answer

Photosynthesis will decrease because chlorophyll reflects green light rather than absorbing it.

Question 7

Which of the following best describes the function of the enzyme rubisco in the Calvin cycle?

Accepted Answer

It catalyzes the fixation of CO$$_2 to $$ribulose bisphosphate (RuBP).

Question 8

Which adaptation allows CAM plants to minimize water loss in arid environments?

Accepted Answer

They open their stomata at night to fix CO$$_2$$ into organic acids.

Question 9

In the light reactions of photosynthesis, what is the primary function of the electron transport chain between Photosystem II and Photosystem I?

Accepted Answer

To create a proton gradient that drives ATP synthesis via chemiosmosis.

Question 10

A scientist adds a chemical that inhibits ATP synthase in mitochondria. Which process will be directly affected, and what is the expected result?

Accepted Answer

Oxidative phosphorylation; ATP production will decrease significantly.

Question 11

Which of the following is a correct comparison between chemiosmosis in mitochondria and chloroplasts?

Accepted Answer

Both use a proton gradient across a membrane to drive ATP synthesis, but mitochondria use energy from food molecules while chloroplasts use energy from light.

Question 12

Which of the following best describes the role of second messengers in cell signaling?

Accepted Answer

They relay signals from membrane receptors to target molecules inside the cell, amplifying the response.

Question 13

A mutation causes a G protein-coupled receptor (GPCR) to remain active even in the absence of its ligand. What is the most likely cellular consequence?

Accepted Answer

Continuous activation of downstream signaling pathways, potentially leading to abnormal cell behavior.

Question 14

Which of the following scenarios best illustrates the concept of feedback inhibition in cellular respiration?

Accepted Answer

High levels of ATP inhibit phosphofructokinase, slowing glycolysis.

Question 15

Which of the following is a direct result of photorespiration in C$$_3$$ plants?

Accepted Answer

Decreased photosynthetic efficiency due to the fixation of O$$_2$$ instead of CO$$_2 by $$rubisco.

Question 16

Which of the following best explains why C$$_4$$ plants are more efficient than C$$_3$$ plants in hot, dry environments?

Accepted Answer

C$$_4$$ plants spatially separate carbon fixation and the Calvin cycle, reducing photorespiration.

Question 17

Which of the following is an example of paracrine signaling?

Accepted Answer

A growth factor released by one cell stimulates nearby cells to divide.

Question 18

Which of the following best describes the function of protein kinases in a phosphorylation cascade?

Accepted Answer

They sequentially add phosphate groups to specific proteins, amplifying the signal.

Question 19

A researcher discovers a new hormone that is hydrophobic and can cross the plasma membrane. Which type of receptor is it most likely to bind, and what is a likely cellular response?

Accepted Answer

An intracellular receptor; activation of gene transcription.

Question 20

Which of the following best describes the process of apoptosis?

Accepted Answer

Programmed cell death that packages cellular components into vesicles for digestion, preventing damage to neighboring cells.

Cellular Respiration, Photosynthesis, and Cell Communication: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard