Chapter 7 Flashcards
1
Q
Begins the breakdown of glucose, is a series of ten enzyme- catalyzed chemical reactions that can be divided into two main phases
A
glycolysis
2
Q
some ATP is used to start the process of glucose oxidation
by the end glucose has been split to 2 three carbon molecules of glyceraldehyde 3-phosphate
A
Energy Investment Phase
3
Q
Energy Pay off Phase
A
chemical bonds are broken, and NAD+ picks up electrons and hydrogen ions forming NADH
the energy released is used to attach to phosphate groups
phosphates are transferred to ADP
4
Q
For each glucose molecule broken down during glycolysis, a net ___ ATPs are formed along with ___ NADH molecules
A
two
two
5
Q
Cellular Respiration
A
energy fuel is converted to ATP
6
Q
Process of Glycolysis
A
1) takes place outside of the Mitochondria
2) energy is added and molecule is split into two
3) NAD+ picks up electrons and hydrogen atoms from NADH
4) some ATP is produced but not much
7
Q
Acetyl CoA Formation
A
1) as the molecule enters the mitochondria, one carbon atom is removed forming CO2
2) electrons are stripped forming NADH
3) coenzyme A attaches to the 2-carbon fragment forming acetyl CoA
8
Q
Citric Acid Cycle
A
1) coenzyme A is removed and the remaining 2-carbon skeleton is attached to 4-carbon molecule
2) the 6 carbon molecule is partially broken down, releasing carbon dioxide
3) 2ATPs are produced by the citric acid cycle for each molecule of glucose
9
Q
Oxidative Phosphorylation
A
1) NADH delivers electrons to an electron transport chain embedded in the inner layer of the mitochondrion
2) electrons are transferred from one electron carrier to another in the electron chain
3) the energy released is used to pump hydrogen ions across the inner membrane creating a higher hydrogen ion concentration
4) hydrogen ions flow across the membrane through a turbine and the flow of hydrogen ions spins the turbine which activates the production of ATP
10
Q
Equation for Aerobic Cellular Respiration
A
C6H12O6 + 6O2»_space;» 6 CO2+ 6H2O+ ATP
11
Q
In glycolysis, glucose is turned into
A
pyruvate
12
Q
Net yield of glycolysis
A
2 pyruvate
2 ATP molecules
2 NADH
13
Q
Glycolysis Intermediate Step
A
1) pyruvate transported to mitochondria
2) in mitochondria, pyrvate converted to acetyl CoA
3) CO2 is released
14
Q
Krebs Cycle Inputs
A
acetyl CoA
15
Q
Krebs Cycle Outputs
A
2 ATP, 6 NADH, 2 FADH2
16
Q
ATP synthase can make ATP by adding a ________ to ADP
A
phosphate
17
Q
Electron transport chain makes more ATP than _________ AND _____ _____
A
glycolysis
krebs cycle
18
Q
If oxygen is not present, pyruvate is metabolized
A
Fermentation
19
Q
Fermentation oxidizes ____ and regenerates ______ which can take part in glycolysis
A
NADH
NAD+
20
Q
Net energy gain in fermentation
A
2 ATP molecules per molecule of glucose
21
Q
Fermentation allows
A
ATP to continually be produced in absence of oxygen
21
Q
Alcohol Fermentation
A
occurs in yeast results in the production of ethanol and CO2
22
Q
Lactic Acid Fermentation
A
occurs in muscle, results in the production of lactate ( lactic acid)
23
Q
initiation of carbohydrate and lipid digestion; release water and glycoproteins called mucins
A
salivary glands
24
secretes molecules required for digestion of fats
liver
25
stores secretions from liver; empties into small intestine
gallbladder
26
secretes enzymes and other materials into small intestine
pancreas
27
where water is absorbed and feces is formed
large intestine
28
propels food particles through the esophagus to the stomach
peristalsis
29
Most of the chemical processing that occurs in the stomach is the digestion of _________ not carbs
proteins
30
The cell lining in the small intestine absorb the ______ that are broken down by ______________
sugars
pancreatic amylase
31
Nutrient absorption depends on the presence of an _______________ gradient that favors the influx of sodium ions into the epithelium of the small intestine
electrochemical
32
____ breaks down protein containing components of the food into individual proteins
HCL
33
HCL _________ proteins, which unfold and separate into long ____________
denature
polypeptides
34
secrete the inactive compound pepsinogen which is converted to the enzyme pepsin by contact with the acidic environment of the stomach
chief cells
35
Pepsin breaks _______ bonds, reducing the long polypeptides to ______ polypeptides
peptide
short
36
produced in the small intestine, activates the pancreatic enzyme trypsinogen, forming trypsin
enterokinase
37
Salivary glands produce _______ which begins to digest fats
lipase
38
secreted by the liver and stored in the gallbladder, contains small lipids called bile salts that emulsify fats
bile
39
Pancreatic lipase breaks up
small fat droplets into monoglycerides and fatty acids
40
Carbohydrates are
monosaccharides
41
Proteins are
amino acids
42
Nucleic acids are
nucleotides
43
Fats are
glycerol and fatty acids
44
Maltose comes from digested
starch
45
____________ secreted by the duodenum breaks down _______, ________, and _________
Disaccharides
maltose
sucrose
lactose
46
47
Gastric Juice contains mostly
water
hydrochloric acid
pepsin
48
Pepsin turns proteins into
polypeptides
49
Protein digestion completes in the _______ intestine
small
50
Name the pancreatic enzymes that digest proteins
trypsin
chyrmotrypsin
carboxypeptidase
aminopeptidase
51
In type 1 diabetes
beta cells of the pancreas are destroyed by the immune system and no insulin is produced
52
In type 2 diabetes
the pancreas produces insulin, but target cells do not take up the glucose creating an excess of glucose in the blood
53
process during which a substance will lose electrons and hydrogen
oxidation
54
process during which a substance will gain electrons and hydrogen
reduction
55
as a result of oxidation, the charge of a substance will become
positive
56
as a result of reduction, the charge of a substance will become
negative
57
A reducing agent is an electron
donor
58
An oxidizing agent is an electron
acceptor
59
Glucose loses electrons in cellular respiration
it undergoes oxidation and is the reducing agent
60
Oxygen gains electrons in cellular respiration
it undergoes reduction and is the oxidizing agent
61
Reactants of cellular respiration
glucose and oxygen
62
Products of cellular respiration
CO2, water, ATP
63
Carbon dioxide in CR results from the oxidation of
glucose
64
Water in CR results from the reduction of
oxygen
65
ATP comes from breaking the _______ bonds of organic molecules
covalent
66
True or False: it the oxygen atom in )2 gas is radiolabeled, scientists would expect to see these labeled oxygen atoms incorporated into CO2 during cellular respiration reactions
false
67
True or False: cellular respiration is an exergonic process, and therefore is anabolic
false
68
Nicotinamide Adenine Dinucleotide
NAD
69
Movement of electrons is facilitated by by the electron carrier
NADH
70
NADH is a modified derivative of two
RNA molecules
71
Types of Phosphorylation
substrate level
oxidative
72
Substrate Level Phosphorylation
73
Oxidative Phosphorylation
74
an enzyme makes ATP by catalyzing the direct transfer of a phosphate group from a substrate to ADP
substrate level phosphorylation
75
redox reactions of the electron transport chain create a hydrogen ion gradient that can power chemiosmosis
oxidative phosphorylation
76
Glycolysis takes place in the
cytosol of the cell
77
During glycolysis
glucose is broken down into two 3-carbon molecules and releases energy
78
Energy Investment Phase
ATP is consumed
glucose 6-phosphate and fructose 6-phosphate was well as G3P and DHAP are isomers
79
Energy Payoff Phase
ATP is released
two g3P molecules are oxidized to two molecules of pyruvate
ATP is produced by SLP
80
Energy Investment Phase
81
Energy Payoff Phase
82
Is oxygen required during glycolysis?
no
83
Enzymes that can transfer a phosphate can be classified as
kinases
84
Enzymes that can convert between isomers can be classified as
isomerases
85
True or False: Fructose 6-phosphate is the intermediate with the most potential energy
false
86
Inputs of Glucose
1 glucose
2 ATP
4 ADP
2 NAD+
87
Outputs of Glucose
2 pyruvate
2 ADP
4 ATP
2 NADH
88
Net of Glycolysis
2 pyruvate
2 ATP
2 NADH
89
In pyruvate oxidation, the carboxyl group of pyruvate is released as a molecule of
CO2
90
In a pyruvate oxidation reaction, pyruvate is __________ to NADH
oxidized
91
NAD+ is ________ to acetyl coA
reduced
92
Inputs per glucose in pyruvate oxidation
2 pyruvate
2 coenzyme A
2 NAD+
93
Outputs per glucose in pyruvate outputs
2 acetyl CoA
2 CO2
2 NADH
94
Pyruvate Oxidation
95
True or False: If pyruvate oxidation were inhibited, acetyl coA would accumulate
false
96
Citric Acid Cycle occurs in the
matrix of the mitochondria
97
To break down glucose in the citric acid cycle, it takes ____ turns of the cycle
2
98
Citric Acid Cycle Steps
coenzyme A chaperones acetyl-CoA to the cycle
the remaining acetyl group is broken down to 2 molecules of CO2
ATP is produced
99
True or False: per one glucose molecule, more electron carriers are reduced or gain electrons, during glycolysis and pyruvate oxidation than during the citric acid cycle
false
100
True or False: in the citric acid cycle, two ATP are made per glucose via substrate level phosphorylation
true
101
Inputs per glucose in citric acid cycle
2 acetyl CoA
6 NAD+
2 FAD
2 ADP
102
Outputs per glucose in citric acid cycle
4 CO2
6 NADH
2 FADH2
2 ATP
103
Oxidative Phosphorylation Steps
electron transport chain
chemiosmosis
104
Electron Transport Chain Steps
when NADH transfers electrons to Complex I it is oxidized to NAD+
when FADH2 transfers electrons to Complex II it is reduced to FA
The final electron acceptor O2, is reduced to H20
Electron transfer causes protein complexes to pump H+ protons into the intermembrane space
105
Chemiosmosis
H+ diffuse back from the intermembrane space into the matrix through the ATP synthase
ADP is phosphorylated to ATP
106
label
107
The movement of electrons through the ETC are indicated by the _______ arrows
yellow
108
When moving from the matrix to the intermembrane space of the mitochondria, the protons move ______their concentration gradient
against
109
When moving from intermembrane space to the matrix of the mitochondria, the protons move _____ their concentration gradient
down
110
The pH of the intermembrane space becomes more ______ as protons are pumped into it
acidic
111
Chemiosmosis is a form of ________ transport
passive
112
alcohol fermentation
113
Outputs per glucose for alcohol fermentation
2 NAD+
2 ethanol/ 2 carbons
2 ATP
2 CO2
114
Which eukaryotes can do this type and are used in brewing, winemaking and baking?
yeast
115
lactic acid fermentation
116
Outputs per glucose for lactic acid fermentation
2 NAD+
2 lactate/ 3 carbons
2 ATP
117
Which organisms carry out lactic fermentation?
prokaryotes
animal muscle cells
118
the metabolic pathway common to both types of fermentation is
glycolysis
119
fermentation regenerates _____ so that glycolysis can continue
NAD+
120
Anaerobic Cellular Respiration
uses inorganic molecules other than oxygen as the final electron acceptor at the end of the electron transport chain
121
Obligate Anaerobes
microorganisms that cannot survive in the presence of O2 may be able to carry out fermentation or anaerobic respiration
122
Facultative Anaerobes
organisms that can survive using fermentation or aerobic respiration
123
Why is the citric acid cycle called a cycle?
The four-carbon acid that accepts the acetyl CoA in the first step of the cycle is regenerated by the last step of the pathway.
124
Where do the reactions of the citric acid cycle occur in eukaryotic cells?
The matrix of the mitochondrion
125
During the reaction C6H12O6 + 6 O2 → 6 CO2 + 6 H2O, which compound is reduced as a result of the reaction?
oxygen
126
A molecule becomes oxidized when it __________.
loses an electron
127
The overall efficiency of respiration (the percentage of the energy released that is saved in ATP) is approximately __________.
34%
128
Most of the ATP produced in aerobic cellular respiration comes from which of the following processes?
Oxidative phosphorylation
129
When a poison such as cyanide blocks the electron transport chain, glycolysis and the citric acid cycle also eventually stop working. Which of the following is the best explanation for this?
NAD+ and FAD are not available for glycolysis and the citric acid cycle to continue.
130
Of the metabolic pathways listed below, which is the most universal metabolic process associated with cellular respiration?
Glycolysis
131
How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen?
Four
132
In the overall process of glycolysis and cellular respiration, __________ is oxidized and __________ is reduced.
glucose; oxygen
133
Of the following molecules in the glycolytic pathway (the process of glycolysis), the one with the most chemical energy is __________.
fructose-1,6-bisphosphate
134
Which of the following best describes the electron transport chain of cellular respiration?
Electrons are passed from one carrier to another, releasing a little energy at each step.
135
In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive oxygen. The mice were closely monitored, and after a few minutes radioactive oxygen atoms showed up in __________.
carbon dioxide
136
Molecular oxygen (O2) has what role in aerobic cellular respiration?
It is the final electron acceptor at the end of the electron transport chain.
137
In the citric acid cycle, for each pyruvate that enters the cycle, one ATP, three NADH, and one FADH2 are produced. For each glucose molecule that enters glycolysis, how many ATP, NADH, and FADH2 are produced in the citric acid cycle?
Two ATP, six NADH, two FADH2
138
Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?
The citric acid cycle
139
After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of __________.
NADH
140
In the absence of oxygen, cells need a way to regenerate which compound following glycolysis?
NAD+
141
Which of the following is a correct description and sequence of events in cellular respiration?
Oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation
142
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the __________.
H+ concentration across the membrane holding ATP synthase
143
The electron transport chain involved in cellular respiration is located in/on the __________.
inner membrane of the mitochondrion
144
Pyruvate is oxidized to
CO2
145
NAD+ is reduced to
NADH
146
FAD is reduced to
FADH2
147
In the oxidation of pyruvate to acetyl CoA, one carbon atom is released as CO2. However, the oxidation of the remaining two carbon atoms—in acetate—to CO2 requires a complex, eight-step pathway—the citric acid cycle. Consider four possible explanations for why the last two carbons in acetate are converted to CO2 in a complex cyclic pathway rather than through a simple, linear reaction.
It is easier to remove electrons and produce CO2 from compounds with three or more carbon atoms than from a two-carbon compound such as acetyl CoA.
148
Four processed of cellular respiration in order
glycolysis> pyruvate processing> citric acid cycle
149
Oxidative phosphorylation is responsible for nearly all the ATP produced in your body.
NADH and FADH2 deliver electrons to the electron transport chain during oxidative phosphorylation.
Without oxygen, oxidative phosphorylation would not occur.
Chemiosmosis is the final step in oxidative phosphorylation.
150
What is being pumped through the inner mitochondrial membrane into the intermembrane space, as indicated by the green arrows?
hydrogen ions
151
Imagine an organism with mutations in complexes I, III, and IV that prevent pumping of hydrogen ions into the intermembrane space but still allow electrons to pass through the electron transport chain. Which of the following is the most likely consequence of these mutations?
ATP synthase will not convert ADP to ATP.
152
Lactate
fermentation in human muscle
153
Ethanol
fermentation in yeast and bacteria
154
Acetyl CoA
aerobic oxidation
155
How many NADH are produced by glycolysis?
2
156
In glycolysis, ATP molecules are produced by _____.
substrate-level phosphorylation
157
Which of these is NOT a product of glycolysis?
FADH2
158
In glycolysis, what starts the process of glucose oxidation?
ATP
159
In glycolysis there is a net gain of _____ ATP.
2
160
In which organisms do cellular respiration and photosynthesis occur?
Cellular respiration occurs in both producers and consumers.
161
Plants require specific inputs to carry out photosynthesis and cellular respiration. Which of the following statements accurately reflect(s) what plants must take in?
Plants take in carbon dioxide from the air
Plants take in both carbon dioxide and oxygen
