Deck 1: Eukaryotic Cell Structure

Question 1

Which of the following statements regarding pH is not true?

A) pH = log[H+]
B) a ten fold change in [H+] alters the pH by 1 unit
C) the pH of pure water is 7
D) many physiological reactions are sensitive to pH
E) in a buffer the pH changes little with addition of small amounts of strong acid or base

Answer 1

pH = log[H+]

Question 2

What is the ratio of protonated to unprotonated lactic acid in a 0.1 M solution of lactic acid at pH 5.86? (pKa of lactic acid is 3.86)

A) 1:100
B) 1:10
C) 1:1
D) 10:1
E) (1:1)

Answer 2

1:100

Question 3

Which of the following is not true regarding water as a solvent?

A) involves covalent interactions with the solute
B) water can dissolve uncharged polar molecules
C) hydrophilic substances readily dissolve in water
D) amphipathic substances have conflicting tendencies in water
E) water can dissolve ionic species

Answer 3

involves covalent interactions with the solute

Question 4

What is required for the formation of a hydrogen bond?

A) A carboxyl group as acceptor
B) A hydrogen attached to an electronegative atom
C) A hydrogen in the proximity of a nitrogen atom
D) A hydrogen that is a part of a double bond
E) A hydrogen that is part of an aliphatic compound

Question 5

Peroxisomes produce much hydrogen peroxide. How are they protected from damage by this reactive oxygen species precursor?

A) Catalase
B) Glutathione peroxidase
C) Rapid export from the peroxisome
D) Rapid synthesis of new peroxisomes
E) Superoxide dismutase

Question 6

Beta-glucuronidase is found in which subcellular fraction of the liver?

A) Total microsomes
B) Lysosomes
C) Golgi apparatus
D) Mitochondria
E) Cytosol

Question 7

What is the pH of a solution in which [H+] = 10x10-9 M?

A) 6
B) 7
C) 8
D) 9
E) 1

Question 8

Which of the following membrane systems are responsible for the bulk of cellular protein and lipid synthesis?

A) Plasma membrane
B) Microbodies
C) Lysosomes
D) Endoplasmic reticulum
E) Golgi complex

Question 9

Which type of organelle is most likely to contain a set of enzymes devoted mainly to catabolism?

A) rough endoplasmic reticulum
B) smooth endoplasmic reticulum
C) storage granule
D) lysosome
E) Golgi apparatus

Question 10

To make an acetate buffer at pH 3.7, what is the required ratio of sodium acetate to acetic acid? (pKa of acetic acid is 4.7)

A) 100:1
B) 10:1
C) 1:1
D) 1:10
E) (1:1)

Question 11

The enzymes responsible for the degradation of sphingolipids are localized in which subcellular structure?

A) Peroxisomes
B) Mitochondria
C) Lysosomes
D) Smooth endoplasmic reticulum
E) Rough endoplasmic reticulum

Question 12

What is the pH of a solution of 0.01M acetic acid, 1M Na acetate? (pKa of acetic acid = 4.75)

A) 4.75
B) 5.75
C) 3.75
D) 6.75
E) 2.75

Question 13

What is the cause of I cell disease?

A) Failure of targeting of enzymes to lysosomes
B) Impermeability of lysosomal membranes
C) Import of extracellular hydrolytic enzymes
D) Lack of primary lysosomes
E) Products of lysosomal hydrolysis accumulate in lysosomes

Question 14

The principal type of reaction carried out by lysosomal enzymes is

A) phosphorolysis.
B) dehydration.
C) dehydrogenation.
D) hydroxylation.
E) hydrolysis.