Biochem 384 Exam 1 Questions and Answers Fully Solved Latest Update 2025-2026
Red blood cells are placed into a solution of unknown solute concentration. After an hour they
have all burst open. The best explanation is that the solution
A) had a very high concentration of solvent
B) none of these answers are correct
C) had no solutes
D) had a very high concentration of solutes
E) was at equilibrium - AnswersC
How do plants, fungi, and bacteria avoid the damaging effects of a hypotonic environment?
A) semipermeable cell walls
B) photosynthesis
C) flexible cells walls
D) none of these answers are correct
E) they lack cell walls - AnswersD
Limonene is a nonpolar molecule. The water molecules around it forms
A) none of the above
B) covalent bonds with limonene and entropy increases
C) ionic bonds with itself and the entropy decreases
D) hydrogen bonds with itself and entropy decreases
E) hydrogen bonds with limonene and the entropy increases - AnswersD
A solution of which of the following would be a good buffer system?
A) CH3COOH and NaCH3COO
,B) HCl and H2O
C) NaOH and KOH
D) none of the above
E) HCl and NaOH - AnswersA
Pyruvate decarboxylase converts pyruvate into
A) Carbon dioxide and acetaldehyde
B) Ethanol and carbon dioxide
C) none of these answers are correct
D) water and glucose
E) carbon monoxide and acetaldehyde - AnswersA
How are polar molecules like glucose transported across a membrane?
A) polar molecules diffuse across the hydrophobic barrier
B) There are proteins that allow the transportation of polar molecules across the membrane
C) none of the above
D) polar molecules cannot ever enter the cell
E) there are holes in the membrane - AnswersB
Calculate the pH of a solution containing 0.105 M HA and 0.146 M A-. The Ka for the weak acid
is 1.8x10^-5
A) 7
B) 4.88
C) 9.11
D) 2.44
E) 4.74 - AnswersB
, If the concentration of aspartate in the cell decreased, what would be the predicted outcome?
A) decreased concentration of fumarate
B) increased concentration of arginine
C) increased concentration of argininosuccinate
D) decreased concentration of citrulline
E) none of the above - AnswersA
Which of the following is the correct solar energy reaction that take place on the sun?
A) 4He-->^4He
B) 4H-->^4He - AnswersB
Which two functional groups are involved in producing a peptide bond?
A) none of these answers are correct
B) alcohol and amino
C) amino and carboxyl
D) amino and thiol
E) methyl and amino - AnswersC
The fluidity of a membrane depends on
A) osmotic pressure
B) the size of the polar head group
C) the number of phospholipids in the membrane
D) the protein composition
E) the degree of saturation of the phospholipids - AnswersE
Red blood cells are placed into a solution of unknown solute concentration. After an hour they
have all burst open. The best explanation is that the solution
A) had a very high concentration of solvent
B) none of these answers are correct
C) had no solutes
D) had a very high concentration of solutes
E) was at equilibrium - AnswersC
How do plants, fungi, and bacteria avoid the damaging effects of a hypotonic environment?
A) semipermeable cell walls
B) photosynthesis
C) flexible cells walls
D) none of these answers are correct
E) they lack cell walls - AnswersD
Limonene is a nonpolar molecule. The water molecules around it forms
A) none of the above
B) covalent bonds with limonene and entropy increases
C) ionic bonds with itself and the entropy decreases
D) hydrogen bonds with itself and entropy decreases
E) hydrogen bonds with limonene and the entropy increases - AnswersD
A solution of which of the following would be a good buffer system?
A) CH3COOH and NaCH3COO
,B) HCl and H2O
C) NaOH and KOH
D) none of the above
E) HCl and NaOH - AnswersA
Pyruvate decarboxylase converts pyruvate into
A) Carbon dioxide and acetaldehyde
B) Ethanol and carbon dioxide
C) none of these answers are correct
D) water and glucose
E) carbon monoxide and acetaldehyde - AnswersA
How are polar molecules like glucose transported across a membrane?
A) polar molecules diffuse across the hydrophobic barrier
B) There are proteins that allow the transportation of polar molecules across the membrane
C) none of the above
D) polar molecules cannot ever enter the cell
E) there are holes in the membrane - AnswersB
Calculate the pH of a solution containing 0.105 M HA and 0.146 M A-. The Ka for the weak acid
is 1.8x10^-5
A) 7
B) 4.88
C) 9.11
D) 2.44
E) 4.74 - AnswersB
, If the concentration of aspartate in the cell decreased, what would be the predicted outcome?
A) decreased concentration of fumarate
B) increased concentration of arginine
C) increased concentration of argininosuccinate
D) decreased concentration of citrulline
E) none of the above - AnswersA
Which of the following is the correct solar energy reaction that take place on the sun?
A) 4He-->^4He
B) 4H-->^4He - AnswersB
Which two functional groups are involved in producing a peptide bond?
A) none of these answers are correct
B) alcohol and amino
C) amino and carboxyl
D) amino and thiol
E) methyl and amino - AnswersC
The fluidity of a membrane depends on
A) osmotic pressure
B) the size of the polar head group
C) the number of phospholipids in the membrane
D) the protein composition
E) the degree of saturation of the phospholipids - AnswersE
