ACS CP ACS CP Biochemistry & Polymer Chemistry 2

Question 1

Glass transition temperature (Tg) in polymers represents:

Accepted Answer

The temperature below which amorphous polymer segments become rigid and glassy

Answer

Tg is the temperature below which amorphous polymer chains lose segmental mobility and the material becomes hard and brittle (glassy state).

Question 2

Which coenzyme is essential for oxidation-reduction reactions and acts as an electron carrier in cellular respiration?

Accepted Answer

NAD+/NADH

Answer

NAD+ (nicotinamide adenine dinucleotide) is the primary electron carrier in cellular respiration, accepting electrons (becoming NADH) in glycolysis, the TCA cycle, and beta-oxidation.

Question 3

Free radical chain polymerization consists of which three fundamental steps?

Accepted Answer

Initiation, propagation, termination

Answer

Free radical chain polymerization proceeds through initiation (radical generation), propagation (chain growth), and termination (radical combination or disproportionation).

Question 4

DNA replication is described as semi-conservative, meaning:

Accepted Answer

Each new double helix contains one original strand and one newly synthesized strand

Answer

Semi-conservative replication, confirmed by the Meselson-Stahl experiment, means each daughter DNA molecule contains one parental strand and one newly synthesized complementary strand.

Question 5

Which type of polymer exhibits both viscous and elastic behavior, behaving like a liquid at long time scales and a solid at short time scales?

Accepted Answer

Viscoelastic polymer

Answer

Viscoelastic polymers exhibit both viscous (liquid-like, time-dependent) and elastic (solid-like, recoverable) deformation depending on the rate and duration of applied stress.

(ACS CP) American Chemical Society (ACS) Certified Professional Practice Test

(ACS CP) American Chemical Society (ACS) Certified Professional Practice Test

ACS CP ACS CP Biochemistry & Polymer Chemistry 2