1
.
What is the most important energy currency used by cells?
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ATP
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ADP
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AMP
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adenosine
2
.
What happens when a chemical is reduced during a reaction?
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The compound is reduced to a simpler form.
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An electron is added to the chemical.
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A hydrogen atom is removed from the substrate.
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It acts as part of a catabolic reaction.
3
.
Which pair of molecules are both oxidizing agents?
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FAD and NAD+
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FADH2 and NADH
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FAD and FADH2
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NAD+ and NADH
4
.
Which of the following reactions releases energy?
5
.
During the second half of glycolysis, what occurs?
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ATP is used up.
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Fructose is split in two.
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ATP is produced.
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Glucose becomes fructose.
6
.
GLUTs are integral membrane proteins that assist in the facilitated diffusion of glucose into and out of cells. What reaction in glycolysis prevents glucose from being transported back out of the cell?
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Hexokinase dephosphorylates glucose using ATP, creating a nonpolar glucose molecule that can’t cross the hydrophilic portion of the plasma membrane.
-
Hexokinase phosphorylates glucose using ADP, creating a polar glucose molecule that can’t cross the hydrophobic interior of the plasma membrane.
-
Hexokinase dephosphorylates glucose using ADP, creating a nonpolar glucose molecule that can’t cross the hydrophilic portion of the plasma membrane.
-
Hexokinase phosphorylates glucose using ATP, creating a polar glucose molecule that can’t cross the hydrophobic interior of the plasma membrane.
7
.
How many ATP molecules are used and produced per molecule of glucose during glycolysis?
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The first half of glycolysis uses 2 ATPs, and the second half of glycolysis produces 4 ATPs.
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The first half of glycolysis produces 2 ATPs, and the second half of glycolysis uses 4 ATPs.
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The first half of glycolysis uses 4 ATPs, and the second half of glycolysis produces 2 ATPs.
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The first half of glycolysis produces 4 ATPS, and the second half of glycolysis uses 2 ATPs.
8
.
What is removed from pyruvate during its conversion into an acetyl group?
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oxygen
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ATP
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B vitamin
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carbon dioxide
9
.
What do the electrons added to do in aerobic respiration?
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They become part of a fermentation pathway.
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They go to another pathway for ATP production.
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They energize the acetyl group in the citric acid cycle.
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They are converted to NADP.
10
.
GTP, which can be converted to ATP, is produced during which reaction of the citric acid cycle?
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isocitrate into -ketoglutarate
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succinyl-CoA into succinate
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fumarate into malate
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malate into oxaloacetate
11
.
How many NADH molecules are produced on each turn of the citric acid cycle?
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one
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two
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three
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four
12
.
What compound receives electrons from NADH?
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FMN
-
ubiquinone
-
cytochrome c1
-
oxygen
13
.
During the chemiosmosis phase of cellular respiration, what is moved? Where does this occur?
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electrons across the cell membrane
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hydrogen atoms across a mitochondrial membrane
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hydrogen ions across a mitochondrial membrane
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glucose through the cell membrane
14
.
What is the role of electrons in the electron transfer chain?
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to dephosphorylate ATP, producing ADP
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to power active transport pumps
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to reduce heme in complex III
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to oxidize oxygen
15
.
What would be the outcome if hydrogen ions were able to diffuse through the mitochondrial membrane into the mitochondria without the need for integral membrane proteins?
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ATP would not be produced.
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Pyruvate would not be produced.
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Citric acid would not be produced.
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Carbon dioxide would not be produced.
16
.
Which of the following fermentation methods can occur in animal skeletal muscles?
-
lactic acid fermentation
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alcohol fermentation
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mixed acid fermentation
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propionic fermentation
17
.
Which molecules are produced in glycolysis and used in fermentation?
-
acetyl-CoA and NADH
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lactate, ATP, and
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glucose, , and
-
pyruvate and
18
.
What are the products of alcohol fermentation?
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methane and
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lactic acid and
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ethanol and
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pyruvic acid and
19
.
In the first step of glycolysis, what is glucose transformed into?
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glucose-6-phosphate
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fructose-1,6-bisphosphate
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dihydroxyacetone phosphate
-
phosphoenolpyruvate
20
.
What is beta-oxidation?
-
the main process used to break down glucose
-
the main process used to assemble glucose
-
the main process used to break down fatty acids
-
the main process used to remove amino groups from amino acids
21
.
Which of the following statements about catabolic pathways is false?
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Carbohydrates can feed into oxidative phosphorylation.
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Glycogen can be broken down into glucose and feed into glycolysis.
-
Amino acids can feed into pyruvate oxidation.
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Fatty acids can feed into the citric acid cycle.
22
.
What impact, if any, do high levels of ATP have on glycolysis?
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They increase the activity of enzymes involved with glycolysis.
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The high levels decrease the activity of enzymes involved with glycolysis.
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They have no effect on the activity of any enzymes involved with glycolysis.
-
The high levels slow down only glycolysis.
23
.
Which of the following enzymes has the greatest control over glycolysis?
-
hexokinase
-
phosphofructokinase
-
glucose-6-phosphatase
-
aldolase
24
.
Which of the following does not occur as ATP concentration increases relative to ADP?
-
decreased activity of phosphofructokinase
-
increased activity of pyruvate kinase
-
decreased activity of isocitrate dehydrogenase
-
slowdown of the electron transport chain