Question 1

Which organelle is primarily responsible for the aerobic steps of cellular respiration, including the Krebs cycle and electron transport chain?

Accepted Answer

Mitochondrion

Question 2

What is the overall balanced chemical equation for aerobic cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} \rightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + \sim 38\ \mathrm{ATP}$$

Question 3

During glycolysis, which molecule is produced as a result of glucose breakdown?

Accepted Answer

Pyruvate

Question 4

Which process directly transfers a phosphate group from a substrate molecule to ADP to form ATP?

Accepted Answer

Substrate-level phosphorylation

Question 5

In cellular respiration, what is the primary function of NADH and FADH2?

Accepted Answer

They transport electrons to the electron transport chain.

Question 6

Which of the following best describes a redox reaction in cellular respiration?

Accepted Answer

A reaction where electrons are transferred from one molecule to another.

Question 7

What is the mnemonic 'LEO the lion goes GER' used to remember?

Accepted Answer

Oxidation is loss of electrons, reduction is gain of electrons

Question 8

Which enzyme is responsible for rearranging glucose into fructose during glycolysis?

Accepted Answer

Isomerase

Question 9

What is the result of decarboxylation during cellular respiration?

Accepted Answer

Removal of a carbon atom, forming CO2

Question 10

Which reaction is represented by the equation $$\mathrm{ADP} + \mathrm{P} + 	ext{energy} ightarrow \mathrm{ATP}$$?

Accepted Answer

Phosphorylation

Question 11

Why are the phosphate bonds in ATP considered 'high-energy'?

Accepted Answer

They are unstable and breaking them releases a large amount of energy.

Question 12

Which step of cellular respiration produces the most ATP?

Accepted Answer

Electron transport chain

Question 13

What is the main difference between substrate-level phosphorylation and oxidative phosphorylation?

Accepted Answer

Substrate-level phosphorylation directly transfers a phosphate group, while oxidative phosphorylation uses energy from electrons.

Question 14

Which molecule acts as the most common electron carrier in cellular respiration?

Accepted Answer

NADH

Question 15

During the conversion of pyruvate to acetyl CoA, which molecule is reduced?

Accepted Answer

NAD+

Question 16

Which process is carried out by kinases and results in the addition of a phosphate group to a molecule?

Accepted Answer

Phosphorylation

Question 17

In the electron transport chain, what is the final electron acceptor?

Accepted Answer

Oxygen

Question 18

Which molecule is less energetic than NADH and also acts as an electron carrier?

Accepted Answer

FADH2

Question 19

What is the main purpose of controlled stepwise oxidation of sugar in cellular respiration compared to direct combustion?

Accepted Answer

To capture energy in activated carrier molecules for ATP synthesis

Question 20

Which of the following best describes the role of ATP synthase in cellular respiration?

Accepted Answer

It synthesizes ATP from ADP and inorganic phosphate using energy from a proton gradient.

Cellular Respiration: Mechanisms of Energy Production in Cells

Study Guide - Practice Questions