CELS-6-revision1

Which two major cellular processes require ATP as their primary energy source?

DNA replication and simple diffusion

Osmosis and passive transport

Active transport and mechanical work by motor proteins

Glycolysis and protein synthesis

None

What is the primary reason why FADH2 produces less ATP than NADH in oxidative phosphorylation?

FADH2 donates electrons to the Electron Transport Chain at Complex I, skipping ATP-generating steps

FADH2 carries lower-energy electrons, which bypass Complex I and enter at Complex II

FADH2 is less stable than NADH and breaks down before ATP can be generated

FADH2 electrons enter at a lower energy level than NADH, resulting in fewer protons being pumped across the membrane

None

Which of the following best describes the relationship between cellular respiration and photosynthesis?

Both processes produce glucose as their final product through enzymatic pathways

Cellular respiration breaks down organic molecules to release ATP, while photosynthesis builds them using energy from light

The products of photosynthesis serve as reactants in cellular respiration to maintain energy flow

Cellular respiration stores energy in chemical bonds, whereas photosynthesis releases it into the environment

None

The enzyme ATP synthase generates ATP by allowing protons (H+) to move __________.

From the cytoplasm into the mitochondrion

From the intermembrane space into the mitochondrial matrix

From the intermembrane space into the cytoplasm

From the mitochondrial matrix into the intermembrane space

None

During anaerobic respiration in human cells, pyruvate is converted into __________ in order to regenerate NAD+ for glycolysis.

Oxygen

Ethanol

Acetyl CoA

Lactate

None

Which of the following statements about oxidative phosphorylation is false?

It occurs in the cytosol and does not require mitochondria

It requires an intact mitochondrial membrane to maintain the proton gradient

It involves the transfer of electrons from NADH and FADH2 to oxygen

It generates water as a final product

None

What happens to the energy stored in high-energy electrons after they are transferred through the Electron Transport Chain?

It is used to produce glucose from pyruvate

It is used to pump protons (H+) into the intermembrane space, creating an electrochemical gradient

It is lost as heat and cannot be used by the cell

It is stored in FADH2 for future ATP production

None

The mitochondrial intermembrane space plays a critical role in ATP synthesis because __________.

It prevents protons from being pumped across the inner membrane

It serves as a temporary reservoir for protons before they flow back into the matrix through ATP synthase

It is the site of glycolysis, which generates ATP molecules

It contains enzymes that break down glucose directly into ATP

None

Which feature of the mitochondrion is critical for the formation of the proton gradient required for ATP synthesis?

The smooth structure of the inner mitochondrial membrane

The highly folded inner membrane

The presence of mitochondrial ribosomes

The ability of the outer membrane to freely allow all molecules to pass

None

10.

Which of the following statements about ATP production is true?

Substrate-level phosphorylation occurs only in oxidative phosphorylation

The majority of ATP is generated through substrate-level phosphorylation in glycolysis

ATP synthase functions by directly using NADH to phosphorylate ADP

Oxidative phosphorylation is responsible for producing the majority of ATP in cellular respiration

None