Cellular Respiration

Free sample questions

Cellular Respiration — sample Biology questions with answers

1. Question 1

   What are the main products of aerobic respiration for one molecule of glucose?

   • A$2\text{ ATP}$, $2\text{ NADH}$, $2$ molecules of lactic acid
   • B$36\text{ ATP}$, $6{\text{ CO}}_2$, $6{\text{ H}}_2\text{O}$
   • C$2\text{ ATP}$, $2{\text{ CO}}_2$, $2$ molecules of ethanol
   • D$4\text{ ATP}$, $2\text{ NADH}$, $2$ molecules of pyruvate

   Answer: B. $36\text{ ATP}$, $6\text{ CO}_2$, $6\text{ H}_2\text{O}$

   Aerobic respiration produces $36\text{ ATP}$, $6{\text{ CO}}_2$, and $6{\text{ H}}_2\text{O}$ for each glucose molecule.

2. Question 2

   Where does glycolysis occur in the cell?

   • AMitochondrial matrix
   • BInner mitochondrial membrane
   • CCytoplasm
   • DNucleus

   Answer: C. Cytoplasm

   Glycolysis occurs in the cytoplasm (cytosol) of the cell.

3. Question 3

   The process of aerobic respiration that produces the most ATP is

   • AGlycolysis
   • BKrebs cycle
   • COxidative phosphorylation
   • DProduction of acetyl CoA

   Answer: C. Oxidative phosphorylation

   Oxidative phosphorylation (electron transport chain and chemiosmosis) produces approximately $34$ of the $36$ ATP.

4. Question 4

   In the absence of oxygen, human muscle cells will produce

   • AEthanol and ${\text{CO}}_2$
   • BLactic acid
   • CAcetyl CoA
   • DCitric acid

   Answer: B. Lactic acid

   During anaerobic respiration in human muscle, pyruvate is converted to lactic acid.

5. Question 5

   The simplified equation for aerobic respiration is

   • A${\text{C}}_6{\text{H}}_{12}{\text{O}}_6+6{\text{O}}_2\to 6{\text{CO}}_2+6{\text{H}}_2\text{O}+36\text{ ATP}$
   • B${\text{C}}_6{\text{H}}_{12}{\text{O}}_6\to 2{\text{C}}_2{\text{H}}_5\text{OH}+2{\text{CO}}_2+2\text{ ATP}$
   • C${\text{C}}_6{\text{H}}_{12}{\text{O}}_6+6{\text{CO}}_2\to 6{\text{O}}_2+6{\text{H}}_2\text{O}+36\text{ ATP}$
   • D${\text{C}}_6{\text{H}}_{12}{\text{O}}_6\to 2{\text{C}}_3{\text{H}}_6{\text{O}}_3+2\text{ ATP}$

   Answer: A. $\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + 36\text{ ATP}$

   The correct aerobic respiration equation is glucose + oxygen producing carbon dioxide, water, and ATP.