Chapter 5 Mastering Microbiology

Anabolic reactions may be characterized as

forming large molecules from smaller molecules.
breaking large molecules into smaller molecules.
exergonic.
producing ATP.
breaking large molecules into smaller molecules to produce ATP.

forming large molecules from smaller molecules.

The (activation /inhibition/saturation) point of an enzyme is reached when all active sites have bound substrate molecules.

saturation

The molecule that an enzyme acts upon is known as its

apoenzyme.
catalyst.
substrate.
holoenzyme.
coenzyme.

substrate

How does a competitive inhibitor slow enzyme catalysis?

They produce products toxic to the enzymes.
They degrade the substrate.
They bind to the substrate.
They compete with the substrate for the enzyme’s active site.

They compete with the substrate for the enzyme’s active site.

What enables competitive inhibitors to bind to a specific enzyme?

Competitive inhibitors have structures that resemble the enzyme’s substrate.
Competitive inhibitors have unique sugars that are attracted to the enzyme.
Competitive inhibitors form unique covalent bonds with enzyme structures.
Competitive inhibitors cover the entire surface of an enzyme.

Competitive inhibitors have structures that resemble the enzyme’s substrate.

If high amounts of sulfanilamide are in the presence of an enzyme whose substrate is PABA, what outcome is expected?

PABA products will increase in concentration.
The substrate will destroy the inhibitor.
Sulfanilamide products will be in higher concentration.
The enzyme will stop functioning.

The enzyme will stop functioning.

Which of the following statements regarding competitive inhibitors is true?

The inhibitor will degrade the substrate.
The inhibitor will destroy the substrate.
The inhibitor will destroy the enzyme.
Competitive inhibitors decrease the rate of enzyme activity.

Competitive inhibitors decrease the rate of enzyme activity.

Why do all enzymatic reactions need activation energy?

Energy is required by an enzyme so that it can be reused.
Energy is required to disrupt a substrate’s stable electron configuration.
Energy allows only the substrate to bind.
Energy is needed for the enzyme to find its substrate.

Energy is required to disrupt a substrate’s stable electron configuration.

What is meant by the statement "Enzymes are biological catalysts"?

Enzymes produce products useful for biology.
Enzymes speed up the chemical reactions in living cells.
Enzymes are products of biological systems.
Enzymes produce biological organisms.

Enzymes speed up the chemical reactions in living cells.

Why are enzymes important to biological systems?

Enzymes increase the energy barrier required of chemical reactions.
Enzymes prevent unwanted chemical by-products from forming.
Enzymes are reuseable.
Enzymes decrease the amount of activation energy required for chemical reactions to occur.

Enzymes decrease the amount of activation energy required for chemical reactions to occur.

During glycolysis, glucose is converted to (pyruvic/acetic/lactic) acid, a molecule that can be used in either fermentation or respiration pathways.

pyruvic

Where is the majority of ATP generated in most eukaryotic cells?

in the cytosol
in the outer membrane of the mitochondria
in the mitochondrial matrix
on ribosomes
in the cytoplasmic membrane

in the mitochondrial matrix

Glycolysis begins with a(n) ________ stage(s).

lysis
energy-conservation
energy-investment
lysis and energy-conservation
energy-investment and conservation

energy-investment

Label the scheme of glucose catabolism.

…

Why is ATP required for glycolysis?

ATP is used to reduce NAD+ to NADH.
ATP is used to convert PEP into pyruvic acid.
ATP is used to convert DHAP into G3P.
ATP makes it easier to break apart glucose into two three-carbon molecules.

ATP makes it easier to break apart glucose into two three-carbon molecules.

Glycolysis literally means

energy producing.
sugar producing.
Embden-Meyerhof.
sugar splitting.

sugar splitting.

How many net ATPs can be made from one molecule of glucose in glycolysis?

Two
One
Six
Four

Two

What carbon molecules remain at the end of glycolysis?

Glucose
Dihydroxyacetone phosphate (DHAP)
Glyceraldehyde 3-phosphate (G3P)
Pyruvic acid

Pyruvic acid

Which of the following statements about glycolysis is true?

All cells perform glycolysis.
Glycolysis is also called the Embden-Meyerhof pathway.
Glycolysis is the main source of NADH in the cell.
Glycolysis produces glucose.

Glycolysis is also called the Embden-Meyerhof pathway.

The various types of chlorophyll differ in the

number of electrons they release.
amount of ATP they produce.
amount of oxygen they utilize.
wavelengths of light they absorb.
amount of light they can absorb.

wavelengths of light they absorb

Light energy is used to fuel the assembly of carbon dioxide and water into carbohydrates in the process known as

fermentation.
gluconeogenesis.
chemiosmosis.
oxidation.
photosynthesis.

photosynthesis

In metabolism, energy that is not used

is used to build up large compounds from smaller ones.
is used to break down large molecules into smaller ones.
is given off as heat.
is stored in the form of ATP.

is given off as heat

The reactions involved in producing larger compounds from smaller compounds is called

metabolism.
anabolism.
catabolism.

anabolism

Where does the energy required for anabolic reactions come from?

Catabolic reactions
Heat
Unused energy from metabolism

catabolic reactions

The use of amino acids to make proteins

is a completely efficient reaction.
is an example of anabolism.
involves the production of ATP.
is an example of catabolism.

is an example of anabolism

What is the role of light energy in photosynthesis?

To produce carbon dioxide
To make glucose in the Calvin-Benson cycle
To manufacture chloroplasts
To produce a proton gradient to make ATP

To produce a proton gradient to make ATP

Which of the following is used in photosynthesis by both plants and cyanobacteria?

Carbon dioxide
Water
Sunlight
Water, sunlight, and carbon dioxide

Water, sunlight, and carbon dioxide

What molecule is used to capture light energy?

ATP
Water
Carbon dioxide
NADPH
Chlorophyll

Chlorophyll

Photosynthesis Equation

Two stages of photosynthesis

Enzymes speed up the rate at which chemical reactions occur within a cell because the enzyme __________.

raises the activation energy of the reaction
lowers the activation energy of the reaction
removes the need for a cofactor
provides a heat source to supply energy to the reaction

lowers the activation energy of the reaction

The purpose of the light-dependent reactions of photosynthesis is to __________.

create ATP from NADPH
absorb light energy and use it for ATP and NADPH synthesis
create glucose from carbon dioxide and water
absorb light energy and use it to catabolize glucose

absorb light energy and use it for ATP and NADPH synthesis

Which of the following is NOT a possible end-product of a fermentation process?

ethanol
CO2
lactic acid
glucose

glucose

Cellular respiration equation