Quiz 6 Study Questions

For the reaction described in the figure shown below, which of the following represents the difference between the free energy content of the reactants and the free energy content of the products?

Arrow D

For the reaction described in the figure shown below, which of the following would be the same in an enzyme-catalyzed or noncatalyzed reaction?

Arrow D

When you have a severe fever, what may be a grave consequence if this is not controlled?

Changes in the folding of enzymes

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?

Competitive inhibition

If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

Nothing; the reaction will stay at equilibrium.

What kinds of molecules can pass through a cell membrane most easily?

Small and hydrophobic

Carbohydrates include what?

Sugars and polysaccharides

Entropy

A measure of disorder or randomness.

How many molecules of glycerol would be present in 1 L of a 1 M glycerol solution?

6.02 x 10^23

Which of the following statements about ATP and ADP is TRUE?

ATP acts as an allosteric inhibitor of many enzymes in catabolic pathways while ADP acts as an allosteric activator of many enzymes in catabolic pathways.

If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

Add more enzyme

What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways?

Energy Coupling

Which of the following statements about enzymes is TRUE?

Enzymes alter the activation energy barrier for a reaction.

Which of the following statements regarding enzymes is FALSE?

Enzymes alter the free energy change (ΔG) of the reactions which they catalyze.

Which of the following is the best explanation for how enzymes speed up the rates of reactions?

Enzymes lower the energy required for reactant molecules to reach their transition state. Enzymes do not alter the free or total energies of the reactant or product molecules.

A solution of protein at room temperature does not readily decompose to form a solution of amino acids because

The activation energy barrier cannot be surmounted.

A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because

The activation energy barrier cannot be surmounted.

For the reaction described in the figure shown below, arrow "C" represents (Different of C is bigger than B)

The activation energy for the noncatalyzed reaction

For the reaction described in the figure shown below, which of the following best describes the reaction?

The amount of free energy released as a result of the catalyzed reaction is indicated by arrow "D".

The oxidation of glucose to CO2 and H2O is highly exergonic: ∆G = -636 kcal/mol. Why doesn't glucose spontaneously combust?

The glucose molecules lack the activation energy at room temperature.

If ATP levels decrease and ADP levels increase

The rates of many catabolic reactions will increase due to increased allosteric activation by ADP, The rates of many anabolic reactions will decrease due to decreased allosteric activation by ATP, The rates of many catabolic reactions will increase due to decreased allosteric inhibition by ATP.

Which of the following are TRUE for anabolic pathways?

They consume energy to build up polymers from monomers

Which of the following is (are) TRUE for anabolic pathways?

They consume energy to build up polymers from monomers.

When two amino acids are joined to form a dipeptide

a dehydration reaction leads to the formation of a peptide bond between the two amino acids

A series of enzymes catalyzes the series of reactions shown below. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. What is substance X?

a substrate

The enzyme phosphofructokinase catalyzes the conversion of fructose-6-phosphate and adenosine triphosphate (ATP) to fructose 1,6-bisphosphate and adenosine diphosphate (ADP). Adenosine monophosphate (AMP) activates the enzyme phosphofructokinase (PFK) by binding at a site distinct from the substrate-binding site. This is an example of

allosteric activation

Which of the following is likely to lead to an increase in the concentration of ATP in a cell?

an increase in a cell's catabolic activity and a decrease in a cell's anabolic activity

How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?

by changing the shape of the enzyme

Kinases are enzymes that catalyze phosphorylation (the addition of a phosphate group) whereas phosphatases are enzymes that catalyze the removal of phosphate groups. A cell can use these enzymes like on-off switches for the activities of various proteins. Which of the following is probably involved?

changes in a protein's charge leading to conformational changes

Spontaneous reactions

do not require an energy input to occur

The active site of an enzyme is the region that

is involved in the catalytic reaction of the enzyme

For the reaction described in the figure shown below, which of the following best describes the reaction?

negative ∆G, spontaneous

In an isolated system

neither energy nor matter can leave the system.

Amines

organic compounds with an amino group

Different enzymes may lower energy activation barriers by

providing a basic environment for the reaction forming a covalent bond with a substrate molecule providing an acidic environment for the reaction

You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule enters the cell?

similarity of the drug molecule to other molecules transported by the target cells.

If the power of the eyepiece of a microscope is 10 and the power of the objective lens for that microscope is 50

the microscope will magnify images 5 times

In a particular reversible reaction, "A" and "B" may be converted to "C" and "D", or "C" and "D" may be converted to "A" and "B". The direction of this reversible reaction will be determined by

the relative concentrations of "A" and "B" versus "C" and "D"

An allosteric regulator

usually acts on multi-subunit enzymes, may decrease the activity level of the enzymes it regulates, may increase the activity level of the enzymes it regulates