Question 1

An active site is the

Accepted Answer

A)  part of the substrate that binds with an enzyme. 
B)  site where enzymes are found in cells. 
C)  site where energy is added to an enzyme catalyst. 
D)  part of the enzyme that binds with a substrate. 
E)  part of the enzyme that binds with an allosteric activator or inhibitor. 
A)  part of the substrate that binds with an enzyme. 
B)  site where enzymes are found in cells. 
C)  site where energy is added to an enzyme catalyst. 
D)  part of the enzyme that binds with a substrate. 
E)  part of the enzyme that binds with an allosteric activator or inhibitor.

Question 2

The reaction below takes place in cells and is catalyzed by the enzyme phosphoglucoisomerase.   At equilibrium, the ratio of fructose 6-phosphate to glucose 6-phosphate is 0.30:1.What will happen if the concentration of glucose 6-phosphate reaches 0.5 nM and the concentration of fructose 6-phosphate reaches 0.8 nM at a particular instant in the cell?

Accepted Answer

A)  Only the forward reaction will occur. 
B)  Only the reverse reaction will occur. 
C)  The rate of the forward reaction will be greater than the rate of the reverse reaction. 
D)  The rate of the reverse reaction will be greater than the rate of the forward reaction. 
E)  The rate of the forward reaction will be the same as the rate of the reverse reaction. 
A)  Only the forward reaction will occur. 
B)  Only the reverse reaction will occur. 
C)  The rate of the forward reaction will be greater than the rate of the reverse reaction. 
D)  The rate of the reverse reaction will be greater than the rate of the forward reaction. 
E)  The rate of the forward reaction will be the same as the rate of the reverse reaction.

Question 3

A change in enzyme shape caused by substrate binding is called _______.

Accepted Answer

The answer of A change in enzyme shape caused by...

Question 4

During the metabolism of glucose, the conversion of glucose to glucose 6-phosphate cannot proceed without the hydrolysis of ATP.Which is a reason for this?

Accepted Answer

A)  Chemical energy can only be converted to chemical energy. 
B)  Glucose 6-phosphate has a lower free energy than glucose. 
C)  The reaction is spontaneous. 
D)  The reaction involves a large decrease in free energy. 
E)  The reaction is endergonic. 
A)  Chemical energy can only be converted to chemical energy. 
B)  Glucose 6-phosphate has a lower free energy than glucose. 
C)  The reaction is spontaneous. 
D)  The reaction involves a large decrease in free energy. 
E)  The reaction is endergonic.

Question 5

Transition-state intermediates have higher energies than the reactants and/or products because

Accepted Answer

A)  energy has been supplied to the system to increase the ground state of the products. 
B)  energy has been used to supply the enzyme to the reaction. 
C)  the chemical bonds of the reactants have been stretched and stressed to near breaking. 
D)  the transition state is further along the time course of the reaction. 
E)  the reactants have been completely used up to form products. 
A)  energy has been supplied to the system to increase the ground state of the products. 
B)  energy has been used to supply the enzyme to the reaction. 
C)  the chemical bonds of the reactants have been stretched and stressed to near breaking. 
D)  the transition state is further along the time course of the reaction. 
E)  the reactants have been completely used up to form products.

Question 6

Many vitamins are essential to human health because they are precursors for coenzymes.Many are also compounds that human cells cannot synthesize themselves and so must be obtained through diet.What would happen if a person could not obtain one of these vitamins from a food source?

Accepted Answer

A)  An enzyme would not fold properly, making it unable to catalyze a vital metabolic reaction. 
B)  An enzyme would lack a critical chemical component required as a participant in the enzyme's metabolic reaction. 
C)  An enzyme would lack a metal ion at its active site that enables the enzyme to carry out its catalytic mechanism. 
D)  An enzyme would lose its ability to bind substrates, making it unable to catalyze an essential chemical reaction. 
E)  An enzyme would lose its substrate specificity, causing it to catalyze many extra reactions that normally do not occur in a cell. 
A)  An enzyme would not fold properly, making it unable to catalyze a vital metabolic reaction. 
B)  An enzyme would lack a critical chemical component required as a participant in the enzyme's metabolic reaction. 
C)  An enzyme would lack a metal ion at its active site that enables the enzyme to carry out its catalytic mechanism. 
D)  An enzyme would lose its ability to bind substrates, making it unable to catalyze an essential chemical reaction. 
E)  An enzyme would lose its substrate specificity, causing it to catalyze many extra reactions that normally do not occur in a cell.

Exam 8: Energy, Enzymes, and Metabolism

An active site is the

A change in enzyme shape caused by substrate binding is called _______.

During the metabolism of glucose, the conversion of glucose to glucose 6-phosphate cannot proceed without the hydrolysis of ATP.Which is a reason for this?

Transition-state intermediates have higher energies than the reactants and/or products because

Many vitamins are essential to human health because they are precursors for coenzymes.Many are also compounds that human cells cannot synthesize themselves and so must be obtained through diet.What would happen if a person could not obtain one of these vitamins from a food source?

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinant Dna and Biotechnology

Mechanisms of Evolution

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons, Glia, and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Functions

Musculoskeletal Systems

Gas Exchange

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

Populations

Species Interactions

Communities

Ecosystems

A Changing Biosphere

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