Download Microbiology - Problem Drill 05: Microbial Metabolism Question No

Microbiology - Problem Drill 05: Microbial Metabolism
Question No. 1 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 1. Anabolism is a metabolic process where ______ are turned into ____molecules.
(A)
(B)
(C)
(D)
Complex, simple
Simple, ATP
Simple, ATP
Simple, complex
Question
A. Incorrect!
This would be for catabolism the opposite of anabolism.
B. Incorrect!
Anabolism often requires energy to assemble the larger more complex molecules. Since ATP is a form of
generated energy this answer is incorrect.
C. Incorrect!
The process of anabolism is the process were simple molecules are metabolized into larger or complex
molecules. This process usually requires the input of energy.
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D. Correct!
Catabolism is the breakdown of complex molecules into smaller less complex molecules. The process
typically generates energy.
Anabolism can be thought of as synthesis of biomolecules. The synthesis of biomolecules comes from
precursor smaller molecules (many of which have been created through the complementary process of
catabolism) and requires energy input.
Catabolism is the breakdown of molecules such as glucose, proteins and lipids. This breakdown product
releases energy and creates precursors for use in the anabolic pathway.
Question
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Question No. 2 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 2. _____ is the breakdown of complex molecules into simpler molecules with the ______ of
energy. (Choose the best answers below to fill in the blanks.)
(A)
(B)
(C)
(D)
Anabolism, input
Anabolism, release
Catabolism, release
Catabolism, input
Question
A. Incorrect!
Anabolism is the assembly of complex molecules from simpler molecules. Anabolism usually requires
the input of energy.
B. Incorrect!
Anabolism is the assembly of complex molecules from simpler molecules. Anabolism usually requires
the input of energy.
C. Correct!
Catabolism is the breakdown of complex molecules into simpler molecules usually releasing energy.
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D. Incorrect!
Catabolism is the breakdown of complex molecules into simpler molecules usually releasing energy not
requiring it.
In the study of metabolism it is useful to determine if a molecule is becoming more or less complex, i.e.
the direction of the reaction.
If the direction is toward lower complexity, as a generalization you can make an educated guess that
energy will be released.
The process of catabolism is associated with the breakdown of complex molecules.
Question
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Question No. 3 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 3. Nutrient molecules with high energy electrons are _______ by catabolic reactions and the
energy is stored in “high energy” bonds like ________.
Question
(A)
(B)
(C)
(D)
Hydrolyzed and DNA
Oxidized and RNA
Deaminated and amino acids
Oxidized and ATP
A. Incorrect!
Hydrolysis is a chemical reaction when a molecule reacts with water. One reactant gets a hydroxyl –OH
and the other a proton +H (not an election).
B. Incorrect!
This answer is partially correct, catabolic reactions do involve oxidation. However RNA is a stable
molecule. In order to be a participant in the storage and or transfer of genetic information the bonds of
RNA must be relatively stable so not high energy.
C. Incorrect!
Deamination is the removal of an amine group from an amino acid. This is a step in breaking down
proteins to ultimately be used in Krebs cycle. However amino acids are not high energy molecules.
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D. Correct!
Catabolism is the process of oxidation of nutrient or complex molecules leading to the creation and
storage of energy in the form of high energy bonds. The most common high energy bond where energy
is stored in the cell is in ATP.
Catabolism is the process of oxidation of nutrient or complex molecules leading to the creation and
storage of energy in the form of high energy bonds. The most common high energy bond where energy
is stored in the cell is in ATP.
Question
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Question No. 4 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 4. The breakdown of glucose to produce large amount of energy in the form of ATP is known as
______.
(A)
(B)
(C)
(D)
Catabolism
Redox
Substrate level phosphorylation
Respiration
Question
A. Incorrect!
Catabolism is the breakdown of complex biomolecules to simple molecules. This is frequently
accompanied by energy being produced. However the over all process is not referred to as catabolism.
B. Incorrect!
REDOX referees to the reduction and oxidation of a sample. Oxidation refers to the loss of an electron
by a molecule. Reduction describes the gain of an electron by a molecule.
C. Incorrect!
Substrate level phosphorylation is the direct transfer of a phosphate from an organic molecule to ADP.
Cells can do this in glycolysis and a small amount of ATP made in the Kreb's cycle is made this way.
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D. Correct!
A series of metabolic processes that the living cell uses to produce energy. This is done through
oxidation of organic molecules.
Cellular respiration, weather prokaryote or eukaryote is a oxidative process. The chemical energy of
organic molecules is releases in a series of organized steps. The steps are frequently accompanied by
use of oxygen (in aerobic respiration) and the release of CO2 and H2O.
Question
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Question No. 5 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 5. Carbohydrates are the primary energy source for microbial metabolism typically in the form
of glucose. Glucose is metabolized further via fermentation or cellular respiration. Before fermentation
or cellular respiration occurs glucose first goes through the ____________.
Question
(A)
(B)
(C)
(D)
TCA cycle
Glycolysis
Kreb’s cycle
Electron transport
A. Incorrect!
TCA cycle is also known as the Kreb’s cycle. It is a series of reactions involving he oxidative metabolism
of biomolecules with the concurrent production of ATP. ATP serves as the main source of cellular
energy.
B. Correct!
Glycolysis the metabolic pathway that occurs in almost all living cells. Glucose is changed in a series of
steps to pyruvic acid which releases energy in the process. Glycolysis precedes the other pathways and
is therefore the primary pathway.
C. Incorrect!
TCA cycle is also known as the Kreb’s cycle. It is a series of reactions involving he oxidative metabolism
of biomolecules with the concurrent production of ATP. ATP serves as the main source of cellular
energy.
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D. Incorrect!
Electron transport chain or system is a series of oxidation-reduction reactions that result in an
electron(s) creating the energy that is used in oxidative phosphorylation. The oxidative phosphorylation
is used to make ATP.
Energy carrying molecules of NADH and FADH2 give their electrons to coenzymes. The enzymes used in
electron transport and oxidative phosphorylation are on the inner membrane of the bacteria. However
the ETC of bacteria is high variable between species. Membrane invaginations form structures called:
mesosomes , respiratory vesicles or lamellar vesicles.
Question
Note in the schematic the metabolic processes available including Krebs, TCA etc. all begin after
glycolysis.
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Question No. 6 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 6. In the preparatory stage of glycolysis glucose is energized by adding _____ phosphate
groups. Two molecules of ATP are _____ in this step resulting in two molecules of glyceraldehyde 3
phosphate. compounds.
Question
(A)
(B)
(C)
(D)
4
2
4
2
and
and
and
and
produced
produced
used
used
A. Incorrect!
Clue is in the question. It states that “Two molecules of ATP” are involved. The most likely scenario
then is that two phosphates are added.
B. Incorrect!
The question does state that two molecules of ATP are used in the preparatory step so the first half of
this answer is correct. However remember that in the preparatory step ATP is used not produced.
C. Incorrect!
Clue is in the question. The question states that “Two molecules of ATP” are involved. The most likely
scenario then is that two phosphates are added. In the preparatory step ATP is used not produced.
Production of ATP will occur in the following steps
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D. Correct!
The question does state that two molecules of ATP are used in the preparatory step so the answer 2 is
correct. In the preparatory step ATP is used not produced. Production of ATP will occur in the following
steps.
Glycolysis has four main steps (although it has 10 distinct chemical reactions).
These key events occur during glycolysis:
1. Preparatory stage, glucose is energized by adding two phosphate groups. Two molecules of ATP are
used in this step and results in two, three-carbon compounds.
2. Substrate level phosphorylation makes 2 molecules of ATP from ADP. During the formation of the two
phosphorylated 3-carbon molecules 4 molecules of ATP are made. This results in a net gain of 2 ATP per
glucose.
3. For every glyceraldehyde 3-phosphate molecule a molecule of NAD+ is reduced to NADH. NADH can
enter the electron transport system generating more ATP by oxidative phosphorylation.
4. Two molecules of pyruvate are made. Pyruvate may be fermented or enter the Krebs cycle depending
on the bacterium.
Question
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Question No. 7 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 7. The end product of glycolysis includes: 2 ATP, 2 NADH and 2_______.
(A)
(B)
(C)
(D)
Urea
Lactic acid
Galactose
Pyruvate
Question
A. Incorrect!
Urea is a product of the urea cycle which is involved in protein breakdown.
B. Incorrect!
Lactate or lactic acid is formed under aerobic conditions. Pyruvate is reduced to lactate.
pyruvate + NADH + H+ → lactate + NAD+
C. Incorrect!
Galactose is a carbohydrate that is used as a metabolite not a product.
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D. Correct!
A single molecule of glucose gives rise to 2 molecules of pyruvate.
Step by step complete solution (the long version). This can be any format, whatever you can type in
Word.
Question
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Question No. 8 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 8. In REDOX reactions molecules are either oxidized or reduced. Which of the following
statements is true of oxidation reduction processes? Reduction reactions trap chemical energy. In
reduction the substrate gains electrons and hydrogens.
Question
(A)
(B)
(C)
(D)
A molecule that has undergone reduction is energy rich.
Reduction reactions release chemical energy.
A molecule that has undergone oxidation is energy rich.
Reduction is the releasing of electrons by a molecule.
A. Correct!
REDOX reactions are involved in the energy release or generation (storage) of chemical energy. As a
rule of thumb it should be remembered that when a molecule is reduced it has acquired an electron and
hydrogens and traps energy.
B. Incorrect!
Reduction reactions trap chemical energy. In reduction the substrate gains electrons and hydrogens. A
molecule that has undergone reduction is energy rich.
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C. Incorrect!
Oxidation reactions release energy. In biological systems, oxidation involves the loss of hydrogen atoms
from a substrate, electrons are usually lost with hydrogen atoms. An oxidized molecule has given up
energy.
D. Incorrect!
Reduction is the acquisition of electrons.
The basics of oxidation and reduction are presented. It is in oxidation reduction that high energy
molecules are created and utilized.
Oxidation reactions release energy. In biological systems, oxidation involves the loss of hydrogen atoms
from a substrate, electrons are usually lost with hydrogen atoms. An oxidized molecule has given up
energy.
Reduction reactions trap chemical energy. In reduction the substrate gains electrons and hydrogens. A
molecule that has undergone reduction is energy rich.
Question
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Question No. 9 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 9. The breakdown products of glucose to glucose-6 phosphate and fructose-6-phospate enter
the anabolic pathway to make glycogen and peptidoglycan, both of which are polysaccharides. This is
an example of _________.
Question
(A)
(B)
(C)
(D)
Catabolism
Anabolism
Fermentation
Electron Transport Chain
A. Incorrect!
Catabolism is the breakdown of molecules into simpler one usually releasing energy. The pathway
described is making the molecule more complex and uses energy.
B. Correct!
This is anabolism because a simple starting molecule is assembled into more complex molecules.
C. Incorrect!
Fermentation is the production of energy under anaerobic conditions.
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D. Incorrect!
Electron transport is the process where the greatest amount of energy in the form of ATP is created.
To answer this question consider the complexity of the starting molecules, glucose and glucose-6phosphate and fructose-6-phospate and then look at the products. The starting molecules are simple
carbohydrates and the end products are more complex. This is therefore and example of anabolism.
Question
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Question No. 10 of 10
Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as needed (3)
Pick the answer (4) Go back to review the core concept tutorial as needed.
Question 10. NAD is used in glycolysis and the Kreb’s cycle during cellular respiration and is converted to
NADH. The _____ potential of NADH can be used to convert ADP to ATP in the electron transport chain.
(A)
(B)
(C)
(D)
Oxidizing
Hydrolyzing
Reducing
Fermenting
Question
A. Incorrect!
The H (hydrogen) is a clue that the NADH is not an oxidizing molecule.
B. Incorrect!
Hydrolyzing is the addition of an OH.
C. Correct!
The hydrogen from NADH is released as a reducing agent. This is used in the electron transport chain to
make ATP.
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D. Incorrect!
Fermentation is the process of energy creation without oxygen and in the absence of the ETC.
The mechanism for oxidative phosphorylation is the gradient of H+ across the cell membrane. This is
called chemiosmotic coupling. NADH enters the ETS chain at the beginning and yields 3 ATP per NADH.
Question
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