Deck 8: Carbohydrates II

Question 1

Which of the following correctly relates the order of intermediates during the synthesis of glycogen?

A) glucose $\rightarrow$ glucose-1-phosphate $\rightarrow$ glucose-6-phosphate $\rightarrow$ UDP-glucose $\rightarrow$ glycogen
B) glucose $\rightarrow$ glucose-6-phosphate $\rightarrow$ glucose-1-phosphate $\rightarrow$ UDP-glucose $\rightarrow$ glycogen
C) glucose $\rightarrow$ glucose-6-phosphate $\rightarrow$ UDP-glucose $\rightarrow$ glucose-1-phosphate $\rightarrow$ glycogen
D) glucose $\rightarrow$ UDP-glucose $\rightarrow$ glucose-1-phosphate $\rightarrow$ glucose-6-phosphate $\rightarrow$ glycogen
E) glucose $\rightarrow$ UDP-glucose $\rightarrow$ glucose-6-phosphate $\rightarrow$ glucose-1-phosphate $\rightarrow$ 0 glycogen

Answer 1

glucose $\rightarrow$ glucose-6-phosphate $\rightarrow$ glucose-1-phosphate $\rightarrow$ UDP-glucose $\rightarrow$ glycogen

Question 2

Which statement is true concerning the metabolic reaction shown below?

A) The enzyme that catalyzes this reaction is called a mutase.
B) The enzyme that catalyzes this reaction is called a kinase.
C) This reaction requires the free energy of ATP hydrolysis.
D) This reaction requires multiple steps catalyzed by a phosphorylase and a mutase.
E) The oxidation of glucose-1-phosphate is higher than that of glucose-6-phosphate.

Answer 2

The enzyme that catalyzes this reaction is called a mutase.

Question 3

The main enzyme of glycogen catabolism is _____, which catalyzes a _____ reaction.

A) glycogen hydrolase; hydrolysis
B) glycogen phosphorylase; phosphorolysis
C) glycogen mutase; mutarotation
D) debranching enzyme; hydrolysis
E) glycogen transferase; glucose residue transfer

Answer 3

glycogen phosphorylase; phosphorolysis

Question 4

The breakdown of glycogen is referred to as ______.

Question 5

The first step in the breakdown of glycogen is catalyzed by ______.

Question 6

______ activates glycogen breakdown.

Question 7

Both glycogen synthesis and glycogen breakdown share the metabolite ______.

Question 8

Which of the following requires large amounts of ribose-5-phosphate?

A) DNA synthesis
B) amino acid synthesis
C) lipid synthesis
D) glycogen synthesis
E) cholesterol synthesis

Question 9

For each molecule of glucose-6-phosphate that enters the oxidative phase of the pentose phosphate pathway, _____ NADPH and _____ CO₂ are produced.

A) 1; 0
B) 1; 1
C) 2; 1
D) 2; 2
E) 3; 2

Question 10

Which of the following enzymes catalyzes an oxidative decarboxylation reaction?

A) glucose-6-phosphate dehydrogenase
B) glyceraldehyde-3-phosphate dehydrogenase
C) glycogen dehydrogenase
D) 6-phosphogluconate dehydrogenase
E) none of the above

Question 11

In the conversion of ribulose-5-phosphate to glycolytic intermediates, which of the following enzymes is used?

A) phosphoglucomutase
B) transketolase
C) phosphoglycerate mutase
D) phosphofructoisomerase
E) none of the above

Question 12

NADPH used in lipid biosynthesis is produced by the ______ pathway.

Question 13

The initial addition of oligosaccharides of N-glycosylated proteins occurs in the _____.

A) lysosome
B) Golgi apparatus
C) endoplasmic reticulum
D) vacuole
E) cytoplasm

Question 14

In the ABO blood type system, how many monosaccharides are found in each of the oligosaccharides for the various blood types?

A) A: 3, B: 4, O: 3
B) A: 4, B: 5, O: 4
C) A: 6, B: 5, O: 5
D) A: 6, B: 6, O: 5
E) A: 5, B: 5, O: 4

Question 15

In a _____, the carbohydrate is responsible for most of the mass; in a _____, the protein is responsible for most of the mass.

A) glycoprotein; proteoglycan
B) proteoglycan; glycoprotein
C) N-linked glycoprotein; O-linked glycoprotein
D) O-linked glycoprotein; N-linked glycoprotein
E) N-linked proteoglycan; O-linked glycoprotein proteoglycan

Question 16

Which of the following describes glycosaminoglycans?

A) found in extracellular space
B) associated with the cytoskeleton
C) bound to other proteins to minimize interactions with water
D) homopolymer composed of only one type of monosaccharide
E) none of the above

Question 17

______ is a heteropolymer composed of D-glucoronate and N-acetyl-D-glucosamine that acts as shock absorber and lubricant.

Question 18

The active portion of the penicillin molecule is the _____ ring.

A) glucopyranose
B) fructofuranose
C) five-membered, sulfur-containing
D) $\beta$ -lactam
E) none of the above

Question 19

The main component of a bacterial cell wall is a ______.