Chapter 21- Cellular Energy Currency Flashcards
1
Q
A set of metabolic pathways that break down complex macromolecules into simpler ones and, in the process, harvest part of their potential energy for use by the cell
A
Catabolism
2
Q
Pathway for the first stage of carbohydrate breakdown is
A
Glycolysis
3
Q
T or F: the glycolysis pathway is in humans but not bacteria
A
F its found in both
4
Q
ATP serves as a “go-between” molecule that couples the __________ reaction of catabolism and the __________ reactions of anabolism
A
Exergonic; endergonic
5
Q
Energy releasing; energy requiring
A
Exergonic; Endergonic
6
Q
ATP is a nucleotide containing what 3 parts
A
- Nitrogenous base
- 5-C sugar
- 1 to 3 phosphorylation groups
7
Q
In a ATP molecule, the 2nd and 3rd phosphorylation groups are bonded by what type of bond
A
Phosphanhydride
8
Q
The first step of glycolysis is to transfer a phosphoryl group from ATP to the c-6 hydroxyl group of glucose. This is a reaction catalyzed by
A
Hexokinase
9
Q
Finish the Equation: ATP—> ADP + phosphoryl group + ___________
A
7 kcal/mol
10
Q
The synthesis of glucose-6-phosphate from glucose and the phosphoryl groups is an ________ reaction
A
Endergonic
11
Q
How much energy is required in the synthesis of glucose-6-phosphate from glucose and phosphoryl group
A
3.0 kcal/mol
12
Q
What is the net energy in glycolysis
A
net energy is 4 kcal/mol
13
Q
Why is ATP called the universal energy currency
A
Because it is the major molecule used by all organisms to store energy
14
Q
Of carbs, fats, and proteins, which is the most readily used energy source
A
Carbohydrates
15
Q
What begins the hydrolysis of starch in the mouth
A
Salivary amylase
16
Q
In the small intestine, pancreatic amylase further hydrolyzes starch into ___________
A
Maltose
17
Q
What enzyme catalyses the hydrolysis of maltose
A
Maltase
18
Q
Sucrose is hydrolyzed by sucrase to __________ and ______________
A
glucose; fructose
19
Q
Lactose is degraded by lactase into _________ & ___________
A
Glucose and galactose
20
Q
Where does digestion of proteins begin in body and why there
A
Stomach… the low pH denatures them so there more easily hydrolyzed by pepsin
21
Q
What enzyme hydrolyzes proteins in stomach
A
Pepsiin
22
Q
Where does digestion of fats begin
A
Small intestine
23
Q
Monosaccharides taken up into epithelial cells of intestine is an energy requiring process called ________
A
Active transport
24
Q
Hydrolysis of fats into fatty acids and glycerol are then taken up by intestinal cells by means of __________ transport
A
Passive
25
The two major energy pathways are:
Glycolysis and citric acid cycle
26
In what form do sugars usually enter the glycolysis pathway
Glucose or fructose
27
T or F: sugars in glycolysis are eventually converted to acetyl CoA
T
28
Fatty acids are converted to __________ and enter the ___________
a. Glycolysis cycle
b. Citric acid cycle
C. Neurotransmitters
D. Acetyl CoA
D and B
29
___________, produced by the hydrolysis of fats enters energy metabolism via glycolysis
Glycerol
30
Acetyl CoA carries what to the citric acid cycle
Acetyl groups, 2-carbon remnants of nutrients
31
What is released/recycled from from the citric acid cycle to carry additional acetyl groups to the pathway
Coenzyme A
32
The electrons and hydrogen ions that are harvested fro the citric acid cycle are used in the process of _______________
Oxidative phosphorylation
33
Glycolysis begins with what substrate
D-glucose
34
Is glycolysis an anaerobic or aerobic process
Anaerobic
35
How many ATP molecules are formed by the process of substrate level phosphorylation
4
36
What is the net gain of ATP in glycolysis
2 molecules
37
Under anaerobic conditions, ________ is used as a source of electrons in fermentation reactions
NADH
38
NAD+ is a coenzyme derived from
The vitamin Niacin
39
Examples of symptoms that arise if a person has a genetic defect in a glycolysis enzymes
- Muscle myopathy
- hemolytic anemia
- Tauri’s disease
40
What causes tauri’s disease
Deficiency in phosphofructokinase
41
Who is most likely to suffer from Tauri’s disease
- males
- U.s Ashkenazi Jews
- Italians
42
T or F: In Patients with late onset Tauri Disease, they often experienced exercise intolerance when they were young
T
43
In patients with Tauri’s disease, wheat types of meals (nutrients) worsen exercise tolerance
High in carbohydrates
44
Early onset Tauri disease is often associated with
A. Seizures
B. Respiratory failure
C. Kidney Failure
D. Cardiomyopathy
E. Paralysis
F. Cortical Blindness
A, B, D, F
45
Phosphoglycerate kinase deficiency is a sex linked genetic disorder located on the ______ chromosome, more specifically on chromosome ______
X; 7
46
In what nationalities is Phosphoglycerate kinase deficiency typically found
U.S. African Americans, Italian, Japanese
47
Symptoms of Phosphoglycerate kinase deficiency:
A. Exercise Intolerance and muscle pain
B. Kidney failure
C. Mental challenge
D. Myoglobinuria
E. Seizures
F. No symptoms
A, C, D, E
Ranges from mental challenge and seizures to slowly progressive myopathy and hemolytic anemia. Book then specifically lists A and D
48
In glycolysis, the first set of steps is the investment of _______ and the second set of remaining reactions result in a ________
ATP energy
Net energy yield
49
What is reaction 1 of glycolysis
Glucose is phosphorylation by hexokinase in a coupled phosphorylation reaction
50
Why is reaction 1 of glycolysis referred to as a “debt” reaction
Purpose of catabolism is production of ATP/energy… the first reaction uses energy to occur but it necessary to start to reaction pathway
51
Reaction 2 of glycolysis is a conversion of a:
A. Aldose to a ketose
B. Ketose to an ester
C. Ketose to an Aldose
D. Ester to an Aldose
A
52
Is reaction 2 of glycolysis, glucose-6-phosphate is rearrange to produce fructose-6-phosphate, a _____________ of glucose-6-phophate
Isomer
53
In reaction 2, the conversion of glucose-6-phosphate to fructose-6-phosphate is an __________ reaction
Enediol reaction
54
The catalyst of reaction 1 in glycolysis
Hexokinase
55
The catalyst of reaction 2 in glycolysis
Phosphoglucose Isomerase
56
The catalyst of reaction 3 in glycolysis
Phosphofructokinase
57
What is the product formed in reaction 3 of glycolysis
Fructose-1,6-biphosphate
58
Catalyst for reaction 4 of glycolysis
Aldolase
59
The two products of reaction 4 in glycolysis from the reactant Fructose-1,6,-biphosphate
Dihydroxyacetone phosphate (DHAP) & Glyceraldehyde-3-phophate (G3P)
60
What happens in reaction 5 of glycolysis
The DHAP of reaction 4 is converted to more G3P
61
The catalyst for reaction 5 in glycolysis
Triode phosphate isomerase
62
Beginning at what reaction in glycolysis will reactions occur twice and why
Reaction 6 because there were 2 G3P molecules created from reactions 4 & 5
63
The first reaction in glycolysis that harvests energy
Reaction 6
64
Catalyst for reaction 6 of glycolysis
Glyceraldehyde-3-phosphate dehydrogenase
65
What happens in reaction 6 of glycolysis
G3P + NAD+ is OXIDIZED to a carboxylic acid + NADH
66
Catalyst of reaction 7 of glycolysis
Phosphoglycerate kinase
67
How it ATP formed in reaction 7 of glycolysis
High energy bond to phosphate group is broken and energy release produces ATP
68
Catalyst of reaction 8 in glycolysis
Phophoglycerate mutase
69
In reaction 8 of glycolysis, 3-phosphoglycerate is isomerized to form
2-phosphoglycerate
70
Catalyst of reaction 9 in glycolysis
Enolase
71
What happens in reaction 9 of glycolysis
Dehydration reaction of 2-phophoglycerate to phosphoenolpyruvate
72
Catalyst of reaction 10 in glycolysis
Pyruvate kinase
73
What is the final product of glycolysis
Pyruvate
74
From reaction 6-10 of glycolysis, how much NADH and ATP molecules are produced
2 NADH
4 ATP—> Net gain 2 ATP d/t ATP consumptions in earlier reaction of pathway
75
A major mechanism for the control of the rate of glycolysis is
Allosteric enzymes
76
Examples of effectors that indicate energy needs of the cell
ATP—> high concentration= sufficient energy
AMP/ADP—> indicate the cell needs ATP produced
77
Which is an allosteric inhibitor of phosphofructokinase?
A. AMP
B. ADP
C. ATP
D. Citrate
C and D
78
Which is an allosteric activator of phosphofructokinase?
A. AMP
B. ADP
C. ATP
A and B
79
The inhibition of phosphofructokinase by citrate is an example of
Feedback inhibiton
80
Activation og phosphpofrucktokinase in earlier reactions results in the activation of Pyruvate kinase. This is an example of what type of activation
Feedforward activation
81
Catabolic reactions that occur with no net oxidation
Fermentations
82
Under aerobic conditions, NADH will be
A. Reduced
B. Reoxidized
B
83
Pyruvate is ________ as NADH is oxidized
Reduced
84
When overworking muscles, what reactions in glycolysis allow us to keep going
Lactate dehydrogenase reduces Pyruvate to lactate. (NADH is reducing agent). As Pyruvate is reduces, NADH is oxidized and NAD+ is again available allowing for glycolysis
85
When overworking muscles and ATP production stops, the point of exhaustion when the muscles can no longer function is called
Anaerobic threshold
86
What are the two products of alcohol fermentation
Ethanol and CO2
87
What is the pathways for alcohol fermentation
Pyruvate decarboxylase removes CO2 from Pyruvate to produce ethanal—> alcohol dehydrogenase catalyzes the reduction of ethanal to ethanol and oxidation of NADH to NAD+
88
The fermentation reaction caused by gangrene
Butyric acid, butanol, acetone fermentation
89
Three shared traits of fermentations
1. They use Pyruvate produced in glycolysis
2. They reoxidize NADH produced in glycolysis
3. They are self-limiting bc the accumulated end product eventually kills products it produced
90
T or F: the pentode phosphate pathwa is an alternative pathway for fructose oxidation
F: alternative for glucose oxidation
91
Precursor (from pentode phosphate pathway) for amino acids phenylalanine, tyrosine and tryptophan
Erythrose-4-phosphate
92
In what type of tissues is pentode phosphate pathway most active
Tissues involved in cholesterol and fatty acid biosynthesis: liver and adipose tissues
93
Glucogenesis is the production of glucose from
No carbohydrate starting materials
94
Glucogenesis occurs primarily in
Liver
95
In Glucogenesis, can be used to make glucose
A. Lactate
B. All amino acids
C. All amino acids except leucine and lysine
D. Glycerol
E. Lipids
A, C, D
96
Glucogenesis pathways is similar to glycolysis in all steps except
1,3,10 in glycolysis are irreversible
97
What is produced in reaction 10 of Glucogenesis
Oxaloacetate
98
The conversion of lactate into glucose is a cyclic process between the liver and skeletal muscles
Cori Cycle
99
What do the three irreversible reactions of glycolysis have in common
Involve transfer of high energy phosphoryl groups
100
T or F: the brain and blood cells can store glucose
F, they cannot
101
What is the total amount of blood glucose in a 70 kg adult
20 grams
102
What is the consumption rate of glucose by the brain
5-6 g an hour
103
T or F: glycogen in skeletal muscle is a main source for blood glucose
F: this glycogen is unable to contribute to blood glucose
104
How is a main long chain on glycogen linked
Alpha (1–>4) glycosidic bonds
105
Glycogen granules are found in the cytoplasm of the (choose 2)
A. Kidneys
B. Liver
C. Muscle cells
D. Heart
E. Intestines
B & C
106
What do glycogen granules do
Exist in complexes with hte enzymes that are responsible for glycogen synthesis and degradation
107
The degradation of glycogen
Glycogenolysis
108
Step 1 of glycogenolysis
The enzyme glycogen phosphorylase catalyzes phophorolysis of a glucose at one end of a glycogen polymer… displaces a glucose unit by a phosphate group. Glucose-1-phosphate is produced w/o using ATP
109
Called the debranching enzyme
Glycosidase
110
In step 2 of glycogenolysis, Glycosidase hydrolyzes the ________ bond at a branch point and frees one molecules of glucose
alpha (1—>6) glycosidic
111
In step 3 of glycogenolysis, glucose-1-phosphate is converted to glucose-6-phosphate by what enzyme
Phosphoglucomutase
112
Two hormones that control glycogenolysis
Glucagon and epinephrine
113
Where is glucagon synthesized
Pancreas
114
Produced by the pancreas in response to high blood sugar levels
Insulin
115
Insulin stimulates the synthesis of __________. This is called ____________
Glycogen; glycogenesis
116
Two enzymes that are involved in glycogen synthesis
Glycogen synthase and Glucokinase
117
How does the liver promote glycogen synthesis and storage
By inhibiting glycogen phosphorylase which inhibits glycogen degradation & stimulating glycogen synthase and glucokinase
118
T or F: glycogenesis and glycogenolysis reactions are the reverse of one another
F
119
In glycogen synthesis, how does the liver trap glucose within the cell
By phosphorylating
120
in the first reaction of glycogen synthesis, the reactants glucose and ATP are catalyzed with glucokinase to form
Glucose-6-phosphate
121
The second reaction of glycogenesis: glucose-6-phosphate is catalyzes by phosphoglucomutase to form
Glucose-1-phosphate
122
In glycogenesis, glucose-1-phosphate must be activated by ________________… a reaction that is catalyzed by ___________
Uridine triphosphate (UTP); pyrophosphorylase
123
In glycogenesis, the enzyme __________ breaks the phosphoester linkage of UDP-glucose and forms an alpha (1–>4) glycosidic bond between glucose and growing chain of glycogen
Glycogen synthase
124
Describe the reactions catalyzed by the branching enzyme
Removes a section of alpha (1–>4) linked glucose units from a glycogen polymer and reattachs them in a alpha (1–>6) linkage elsewhere in the chain
125
Hyperglycemia is from insulin stimulating what
the uptake of glucose
126
Hypoglycemia stimulates what
Glycogen phosphorylase
127
An inherited defect of glycogen metabolism causes by a defective gene for glucose-6-phosphatase
Gierke’s Disease
128
What are two symptoms of Gierke’s Disease
Massive liver and blood sugar drops between meals
129
Causes by a genetic defect in the debranching enzyme
Cori’s Disease
130
Results from a genetic defect in the branching enzyme resulting in a decrease efficiency of glycogen storage
Anderson’s Disease
131
Disease where muscle cells lack the enzyme glycogen phosphorylase and cannot degrade glycogen to glucose and thus have little tolerance for physical exercise
McArdle’s disease
132
What is the difference between catabolism and anabolism in terms of their relationship to ATP
Catabolic reactions generate ATP while anabolic reactions require ATP
133
Why are red blood cells particularly susceptible to a deficiency of an enzyme in the glycolysis pathway?
RBC are completely dependent on glycolysis for their ATP… Defect would lead to insufficient ATP and would cause RBC death
