Biology

Cellular Respiration and Enzymes

1,551 Questions

Explore key concepts of cellular respiration, including glycolysis, the Krebs cycle, and the electron transport chain. These questions also cover ATP production, anaerobic respiration, and essential metabolic pathways. This topic forms a core part of the biology syllabus for many competitive examinations.

Glycolysis and metabolic pathwaysKrebs cycle processesElectron transport chainATP production countAnaerobic respiration products

Cellular Respiration and Enzymes Questions

Multiple choice

Where does the process of glycolysis occur?

  1. outer membrane of the mitochondria

  2. inner membrane of the mitochondria

  3. matrix of the mitochondria

  4. cytosol
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Glycolysis takes place in the cytosol (cytoplasm) of the cell, outside of the mitochondria.

Multiple choice

Aerobic respiration produces:

  1. A large yield of ATP (34-36 ATP) from glucose

  2. A variable yield of ATP depending on light intensity

  3. A small yield of ATP (2 ATP) from glucose

  4. No ATP - all ATP is produced during anerobic respiration
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Aerobic respiration is highly efficient, utilizing oxygen to break down glucose completely, resulting in a high yield of ATP (typically 34-36 molecules).

Multiple choice

Aerobic respiration in humans produces:

  1. Carbon dioxide and water

  2. Lactate

  3. Ethanol and carbon dioxide

  4. Oxygen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In human aerobic respiration, glucose reacts with oxygen to produce carbon dioxide, water, and energy (ATP).

Multiple choice

Aerobic respiration takes place in the:

  1. Cytoplasm and Mitochondria

  2. Cytoplasm only

  3. Nucleus and cytoplasm

  4. Nucleus and Golgi apparatus
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Aerobic respiration begins in the cytoplasm (glycolysis) and is completed in the mitochondria (Krebs cycle and electron transport chain).

Multiple choice

Anaerobic respiration produces:

  1. A large yield of ATP (34-36 ATP) from glucose

  2. A variable yield of ATP depending on light intensity

  3. A small yield of ATP (2 ATP) from glucose

  4. No ATP - all ATP is produced during aerobic respiration
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Anaerobic respiration is much less efficient than aerobic respiration, yielding only 2 ATP per glucose molecule.

Multiple choice

ATP is used as ...

  1. A component of glucose

  2. A source of energy in the cell after ADP is formed.

  3. A monomer for protein synthesis

  4. An immediate source of energy in the cell
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

ATP (Adenosine triphosphate) acts as the primary energy currency of the cell, providing immediate energy for cellular work.

Multiple choice

ATP stands for:

  1. Adenosine diphosphate

  2. Adenosine triphosphate

  3. Adenotine triphosphate

  4. Adenotine diphosphate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

ATP is the abbreviation for Adenosine triphosphate, which consists of an adenosine molecule bonded to three phosphate groups.

Multiple choice

Cell respiration is defined as the controlled release of....

  1. Energy from organic compounds to produce ATP

  2. ATP from organic compounds to produce glucose

  3. Glucose from organic compounds to produce ATP

  4. Energy from organic compounds to produce glucose
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cellular respiration is the metabolic process by which cells break down organic molecules like glucose to release energy, which is then stored in the form of ATP.

Multiple choice

Energy is released when mitochondria break down glucose or sugar in a process known as _______.

  1. osmosis

  2. cellular respiration

  3. cellular regeneration

  4. tissue
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cellular respiration is the metabolic process where mitochondria break down glucose in the presence of oxygen to produce ATP, releasing energy for the cell. Osmosis is the passive movement of water across a membrane, and cellular regeneration refers to tissue repair. Therefore, cellular respiration is the correct term.

Multiple choice

Nitogenase having

  1. 6 unit

  2. 7 unit

  3. 10 unit

  4. 9unit
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The nitrogenase enzyme complex is composed of two proteins: the Fe protein (a homodimer with 2 subunits) and the MoFe protein (a heterotetramer with 4 subunits). Together, they form a functional complex consisting of 6 subunits.