introduction Flashcards
What is the substance acted upon by an enzyme called?
A. Product
B. Holoenzyme
C. Substrate
D. Isoenzyme
Answer: C
Explanation: The substrate is the substance acted upon by an enzyme.
What happens to enzymes with a small molecular weight when exposed to varying conditions?
A. They become more active
B. They are faster to denature
C. They synthesize in an inactive state
D. They do not require cofactors
Answer: B
Explanation: Enzymes with small molecular weight denature faster.
Which of the following best describes the term ‘amphoteric’ in relation to enzymes?
A. Able to react both as an acid or base
B. Easily denatured with high molecular weight
C. Found only in specific tissues
D. Always requiring a cofactor to function
Answer: A
Explanation: Amphoteric substances can react both as an acid and a base.
Which site on an enzyme is other than the active site and may lead to inhibition of substrate attachment?
A. Active site
B. Allosteric site
C. Substrate site
D. Product site
Answer: B
Explanation: Allosteric sites are locations other than the active site that can affect enzyme activity.
Which of the following is a non-protein organic biochemical that takes part in enzyme reactions?
A. Activators
B. Coenzymes
C. Holoenzyme
D. Apoenzyme
Answer: B
Explanation: Coenzymes are non-protein organic molecules essential for enzyme activity.
In which structure of enzymes are the interactions among side chains/groups significant?
A. Primary Structure
B. Secondary Structure
C. Tertiary Structure
D. Quaternary Structure
Answer: C
Explanation: The tertiary structure involves interactions among side chains of the polypeptide chain.
What term refers to the combined enzyme and coenzyme?
A. Apoenzyme
B. Holoenzyme
C. Isoenzyme
D. Isoform
Answer: B
Explanation: Holoenzyme is the term for the combination of an enzyme and its coenzyme.
Which of the following is an example of an inorganic ionic cofactor?
A. NAD
B. Pyridoxal phosphate
C. Mg++
D. Peptide bond
Answer: C
Explanation: Mg++ is an example of an inorganic ionic cofactor, specifically a metal ion.
Which structure of an enzyme consists of helical or beta pleated sheets maintained by hydrogen bonds?
A. Primary Structure
B. Secondary Structure
C. Tertiary Structure
D. Quaternary Structure
Answer: B
Explanation: The secondary structure consists of helical or beta pleated sheets maintained by hydrogen bonds.
What is the term for different forms of an enzyme with different genetic origins but catalyze the same reaction?
A. Isoenzymes
B. Isoforms
C. Holoenzymes
D. Apoenzymes
Answer: A
Explanation: Isoenzymes are different forms of an enzyme with different genetic origins that catalyze the same reaction.
What is the simplest enzyme structure consisting of a sequence of amino acids?
A. Primary Structure
B. Secondary Structure
C. Tertiary Structure
D. Quaternary Structure
Answer: A
Explanation: The primary structure is the simplest enzyme structure, consisting of a sequence of amino acids.
What is the function of a prosthetic group in an enzyme reaction?
A. It can be removed easily by dialysis
B. It is an inorganic ionic cofactor
C. It cannot be removed from its attachment to an enzyme
D. It is always a metal ion
Answer: C
Explanation: A prosthetic group cannot be removed from its attachment to an enzyme using dialysis.
Which of the following increases the catalytic activity of an enzyme when it binds to a specific site?
A. Coenzymes
B. Activators
C. Substrates
D. Products
Answer: B
Explanation: Activators increase the catalytic activity of an enzyme when they bind to specific sites.
Which structure of an enzyme involves more than one polypeptide chain forming a functional unit?
A. Primary Structure
B. Secondary Structure
C. Tertiary Structure
D. Quaternary Structure
Answer: D
Explanation: The quaternary structure involves more than one polypeptide chain forming a functional unit.
What is the term for an enzyme without its cofactor?
A. Apoenzyme
B. Holoenzyme
C. Isoenzyme
D. Prosthetic group
Answer: A
Explanation: An apoenzyme is an enzyme without its cofactor.
