Cell Structure & Organelles MCQs with Answers

Which of the following is a five-carbon compound in the Kreb's cycle?

• A.Citrate
• B.Succinate
• C.Oxaloacetate
• D.Alpha-ketoglutarate

When the rate of an enzymatic reaction cannot be increased by adding more substrate, the enzyme is said to be ?

• A.Denatured
• B.Inhibited
• C.Saturated
• D.Hydrolyzed

What occurs in metaphase of mitosis?

• A.Nuclear membrane breaks down
• B.Chromosomes move toward opposite poles
• C.Chromosomes line up on the equator of the cell
• D.Cytoplasm divides into two daughter cells

Induced fit model of enzyme activity suggests that an enzyme ?

• A.Has a rigid active site that fits only one substrate
• B.Works only at high temperatures
• C.Is consumed during the reaction
• D.Can catalyze related reactions

How many carbon atoms are present in pyruvic acid?

• A.2
• B.3
• C.4
• D.5

How many NADH are produced when one Acetyl co-A is oxidized during Krebs's cycle?

• A.2
• B.6
• C.4
• D.3

Presence of enzyme does not affect the nature or properties of ?

• A.Substrate
• B.End products
• C.Activation energy
• D.Reaction rate

Which metabolic pathway is common to both fermentation and cellular respiration?

• A.Krebs cycle
• B.Electron transport chain
• C.Glycolysis
• D.Oxidative phosphorylation

Enzyme activity decreased by ?

• A.Activator
• B.Inhibitor
• C.Coenzyme
• D.Substrate

The helical structure of a protein is kept by formation of hydrogen bond between amino acid molecules which are ?

• A.In successive turns of spiral
• B.In the same turn of spiral
• C.Between adjacent polypeptide chains
• D.Between amino acids and water molecules