Question 1

In alcohol fermentation from glucose, the two oxidation-reduction reactions are catalyzed by:

Accepted Answer

A)  glyceraldehyde-3-phosphate dehydrogenase and alcohol dehydrogenase 
B)  glyceraldehyde-3-phosphate dehydrogenase and pyruvate decarboxylase 
C)  alcohol dehydrogenase and pyruvate decarboxylase 
D)  lactate dehydrogenase and pyruvate decarboxylase 
E)  glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase 
A)  glyceraldehyde-3-phosphate dehydrogenase and alcohol dehydrogenase 
B)  glyceraldehyde-3-phosphate dehydrogenase and pyruvate decarboxylase 
C)  alcohol dehydrogenase and pyruvate decarboxylase 
D)  lactate dehydrogenase and pyruvate decarboxylase 
E)  glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase

Question 2

For phosphofructokinase-1:

Accepted Answer

A)  Low ATP stimulates the enzyme, but fructose-2,6-bisphosphate inhibits 
B)  High ATP stimulates the enzyme, and fructose-2,6-bisphosphate activates 
C)  High ATP stimulates the enzyme, but fructose-2,6-bisphosphate inhibits 
D)  Low ATP stimulates the enzyme, and fructose-2,6-bisphosphate activates 
E)  ATP and fructose-2,6-bisphosphate both inhibit the enzyme 
A)  Low ATP stimulates the enzyme, but fructose-2,6-bisphosphate inhibits 
B)  High ATP stimulates the enzyme, and fructose-2,6-bisphosphate activates 
C)  High ATP stimulates the enzyme, but fructose-2,6-bisphosphate inhibits 
D)  Low ATP stimulates the enzyme, and fructose-2,6-bisphosphate activates 
E)  ATP and fructose-2,6-bisphosphate both inhibit the enzyme

Question 3

Addition of water across a double bond, or removal of water to form a double bond, is catalyzed by a subclass of the lyase class of enzymes. Which of these enzymes would be a lyase?

Accepted Answer

A)  glyceraldehyde-3-phosphate dehydrogenase 
B)  triose phosphate isomerase (TPI) 
C)  phosphoglycerate mutase 
D)  hexokinase 
E)  enolase 
A)  glyceraldehyde-3-phosphate dehydrogenase 
B)  triose phosphate isomerase (TPI) 
C)  phosphoglycerate mutase 
D)  hexokinase 
E)  enolase

Question 4

Dihydroxyacetone phosphate is:

Accepted Answer

A)  an aldotriose. 
B)  an enantiomer of glyceraldehyde-3-phosphate. 
C)  derived from C4-C6 of fructose-1,6-bisphosphate. 
D)  isomerized to glyceraldehyde-3-phosphate by triose phosphate isomerase (TPI). 
E)  the least abundant component of the TPI reaction at equilibrium. 
A)  an aldotriose. 
B)  an enantiomer of glyceraldehyde-3-phosphate. 
C)  derived from C4-C6 of fructose-1,6-bisphosphate. 
D)  isomerized to glyceraldehyde-3-phosphate by triose phosphate isomerase (TPI). 
E)  the least abundant component of the TPI reaction at equilibrium.

Question 5

Glucokinase has a Km value of 10.0 mM, whereas hexokinase has a Km value of 0.1 mM. This is consistent with which of the following?

Accepted Answer

A)  glucokinase acts on glucose at low concentrations. 
B)  glucokinase acts on glucose only at high glucose concentrations. 
C)  glucokinase phosphorylates most of the glucose at low glucose levels. 
D)  hexokinase acts on glucose only at high levels of glucose. 
E)  hexokinase acts at about half-maximal velocity at glucose concentrations of 4-5 mM. 
A)  glucokinase acts on glucose at low concentrations. 
B)  glucokinase acts on glucose only at high glucose concentrations. 
C)  glucokinase phosphorylates most of the glucose at low glucose levels. 
D)  hexokinase acts on glucose only at high levels of glucose. 
E)  hexokinase acts at about half-maximal velocity at glucose concentrations of 4-5 mM.

Question 6

PEP and 2-PG have similar amounts of potential metabolic energy with respect to decomposition to Pi, CO2 and H2O, but the enolase reaction:

Accepted Answer

A)  creates a much more unstable reactive intermediate. 
B)  rearranges 2-PG into a form from which more potential energy can be released by hydrolysis. 
C)  rearranges 2-PG to a form with greater binding potential to the enzyme. 
D)  changes the ΔG of the reaction to increase the potential energy. 
E)  none are true. 
A)  creates a much more unstable reactive intermediate. 
B)  rearranges 2-PG into a form from which more potential energy can be released by hydrolysis. 
C)  rearranges 2-PG to a form with greater binding potential to the enzyme. 
D)  changes the ΔG of the reaction to increase the potential energy. 
E)  none are true.

Question 7

NADH, ____ and ____ are products of glycolysis, and the NADH must be recycled to ____ before it becomes limiting in glycolysis.

Accepted Answer

A)  ATP; pyruvate; NAD+ 
B)  NAD+; ATP; pyruvate 
C)  ATP; NAD+; ATP 
D)  ATP; pyruvate; lactate 
E)  None are true 
A)  ATP; pyruvate; NAD+ 
B)  NAD+; ATP; pyruvate 
C)  ATP; NAD+; ATP 
D)  ATP; pyruvate; lactate 
E)  None are true

In alcohol fermentation from glucose, the two oxidation-reduction reactions are catalyzed by:

For phosphofructokinase-1:

Addition of water across a double bond, or removal of water to form a double bond, is catalyzed by a subclass of the lyase class of enzymes. Which of these enzymes would be a lyase?

Dihydroxyacetone phosphate is:

Glucokinase has a K_m value of 10.0 mM, whereas hexokinase has a K_m value of 0.1 mM. This is consistent with which of the following?

PEP and 2-PG have similar amounts of potential metabolic energy with respect to decomposition to P_i, CO₂ and H₂O, but the enolase reaction:

NADH, and are products of glycolysis, and the NADH must be recycled to before it becomes limiting in glycolysis.

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, Tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Membranes and Membrane Transport

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Enzymeskinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Metabolism: an Overview

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Lipid Biosynthesis

Nitrogen Acquisition and Amino Acid Metabolism

Synthesis and Degradation of Nucleotides

Metabolic Integration and Organ Specialization

Dna Metabolism: Replication, Recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

Completing the Protein Life Cycle: Folding, Processing, and Degradation

The Reception and Transmission of Extracellular Information

Filters

Exam 18: Glycolysis

In alcohol fermentation from glucose, the two oxidation-reduction reactions are catalyzed by:

For phosphofructokinase-1:

Addition of water across a double bond, or removal of water to form a double bond, is catalyzed by a subclass of the lyase class of enzymes. Which of these enzymes would be a lyase?

Dihydroxyacetone phosphate is:

Glucokinase has a Km value of 10.0 mM, whereas hexokinase has a Km value of 0.1 mM. This is consistent with which of the following?

PEP and 2-PG have similar amounts of potential metabolic energy with respect to decomposition to Pi, CO2 and H2O, but the enolase reaction:

NADH, ____ and ____ are products of glycolysis, and the NADH must be recycled to ____ before it becomes limiting in glycolysis.

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, Tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Membranes and Membrane Transport

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Enzymeskinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Metabolism: an Overview

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Lipid Biosynthesis

Nitrogen Acquisition and Amino Acid Metabolism

Synthesis and Degradation of Nucleotides

Metabolic Integration and Organ Specialization

Dna Metabolism: Replication, Recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

Completing the Protein Life Cycle: Folding, Processing, and Degradation

The Reception and Transmission of Extracellular Information

Filters

Glucokinase has a K_m value of 10.0 mM, whereas hexokinase has a K_m value of 0.1 mM. This is consistent with which of the following?

PEP and 2-PG have similar amounts of potential metabolic energy with respect to decomposition to P_i, CO₂ and H₂O, but the enolase reaction:

NADH, and are products of glycolysis, and the NADH must be recycled to before it becomes limiting in glycolysis.