FREE BACE Chemistry and Biochemistry Questions and Answers 2

Question 1

What is the chemical basis for enzyme catalysis?

Accepted Answer

Enzymes lower the activation energy of reactions increasing the reaction rate without being consumed

Answer

Enzymes lower the activation energy (Ea) of biochemical reactions by stabilizing the transition state, dramatically increasing the reaction rate without being permanently altered.

Question 2

What is the difference between an agonist and an antagonist in the context of receptor pharmacology?

Accepted Answer

An agonist binds and activates a receptor; an antagonist binds but blocks receptor activation

Answer

Agonists bind receptors and trigger their biological response; antagonists bind receptors but block the response, often competing with natural agonists.

Question 3

What is the Michaelis-Menten constant (Km) a measure of?

Accepted Answer

The substrate concentration at which the reaction rate is half of Vmax reflecting the affinity of the enzyme for its substrate

Answer

Km is the substrate concentration at which reaction rate = Vmax/2. A low Km indicates high affinity (enzyme is half-saturated at low substrate concentration); a high Km indicates low affinity.

Question 4

What type of chemical bond holds the two strands of the DNA double helix together?

Accepted Answer

Hydrogen bonds between complementary base pairs

Answer

The two DNA strands are held together by hydrogen bonds between complementary base pairs (A-T: 2 hydrogen bonds; G-C: 3 hydrogen bonds).

Question 5

What is the primary structure of a protein?

Accepted Answer

The linear sequence of amino acids linked by peptide bonds

Answer

Primary structure is the sequence of amino acids in the polypeptide chain, connected by peptide bonds — it is the most fundamental level of protein structure.

BACE - Biotechnician Assistant Credentialing Exam Practice Test

BACE - Biotechnician Assistant Credentialing Exam Practice Test

FREE BACE Chemistry and Biochemistry Questions and Answers 2