Exam 4 Flashcards
(140 cards)
1
Q
What happens to most of the glucose-6-phosphate in liver versus muscle tissue?
A
In the muscle it is used for energy, in liver it is converted to glucose to be transported in the blood to other cells. It can be converted back to glycogen in the muscle and liver if not needed
2
Q
What hormone is released from the pancreas in response to low blood glucose levels?
A
glucagon
3
Q
T/F Insulin can enter the cell but glucagon cannot
A
False
4
Q
The hydrolysis of ATP is: ATP ADP + ? + 7kcal/mole. What is the missing product?
A
inorganic phosphate (Pi)
5
Q
Where does gluconeogenesis take place?
A
liver
6
Q
What effect does insulin have on gluconeogenesis?
A
inhibits
7
Q
What is the final product of glycolysis in humans in anaerobic conditions?
A
lactic acid
8
Q
T/F The rate of glycolysis decreases when the cell’s ATP concentration is high
A
True
9
Q
What hormone or hormones will stimulate glycogenolysis in muscle?
A
only epinephrine
10
Q
What compounds can be converted into new glucose in gluconeogenesis?
A
gylcerol, lactic acid, and some amino acids
11
Q
What two enzymes are needed by a yeast cell to convert pyruvic acid to ethanol?
A
decarboxylase and dehydrogenase
12
Q
Why are there no receptor sites on muscle for glucagon?
A
Glycogen in the muscle is only for the muscle and is not affected by low blood sugar
13
Q
What hormone is called “The famine hormone”
A
glucagon
14
Q
What functional group or groups are found in a pyruvic acid molecule?
A
ketone and carboxylic acid
15
Q
Which of these hormones cannot get into the cell?
A
insulin, glucagon, and epinephrine
16
Q
The enzyme for step 9 in glycolysis is called “Enolase”. What type of enzyme is this?
A
lyase
17
Q
T/F Without oxygen, a cell cannot do gycolysis
A
False
18
Q
When glucagon affects a liver cell, a phosphate is attached to both glycogen synthetase and glycogen phosphorylase. Which enzyme is activated?
A
glycogen phosphorylase
19
Q
Where does gluconeogenesis occur?
A
only liver
20
Q
Which statement concerning glycogenolysis is FALSE?
A
It is activated by the secretion of insulin into the bloodstream
21
Q
Where does glucose to CO2 + H2O take place?
A
all cells
22
Q
What hormone or hormones will stimulate entry of glucose into the muscle?
A
only insulin
23
Q
T/F Glucose-6-phosphate (in glycolysis) is always converted into pyruvic acid in both liver and muscle
A
False
24
Q
What type of enzyme catalyzes step 2 of glycolysis?
A
mutase
25
T/F Digestion cannot take place within a cell
True
26
Where is galactose converted to glucose?
liver
27
T/F the main source of energy for the liver is glycolysis of its own glycogen
False
28
What type of enzyme catalyzes step 6 of glycolysis?
dehydrogenase
29
What process converts glycerol to glucose?
gluconeogenesis
30
What reaction in step 6 of glycolysis is endothermic?
synthesis of a phosphate ester from inorganic phosphate
31
Which is true of fatty acids?
They can be stored in adipose tissue as triglycerides. They cannot be used by the brain for energy because of the blood/brain barrier and they cannot be used by red blood cells for energy because they have no mitochandria.
32
How much ATP is produced from glycolysis of 2 glucose molecules?
4 ATP
33
Where is insulin made?
pancreas
34
Glycogenesis occurs under which of the following conditions
When digestion of polysaccharides provides high levels of blood glucose
35
Why is pyruvic acid converted to lactic acid in muscle cells doing anerobic work?
To convert NADH back to NAD and muscle cell can only do glycolysis in these conditions, and needs more oxidizing agent for step 6
36
Which statements about glycolysis are correct?
It is found in the cytoplasm, all cells can do it, muscles will do a lot of glycolysis during strenuous exercise and it occurs in aerobic and anaerobic conditions
37
T/F Fructose needs two phosphates on it before entering step 4 of glycolysis, so that each 3 carbon product will contain a phosphate
True
38
Which statements are true concerning the reaction: glucose-1-phosphate to glycogen?
the enzyme needed is glycogen synthetase and the energy needed to synthesize glycogen comes from breaking the high energy phosphate bond on glucose
39
Where does glycogen to glucose take place?
only liver and muscle cells
40
What is the starting point of glycolysis in a red blood cell?
glucose
41
Which is the highest energy compound?
ATP
42
Which cells need insulin to help the passage of glucose into the cell?
liver, muscle, and adipose tissue
43
T/F The rate of glycolysis decreases when the cell's ATP concentration is high
True
44
Which of the following is a possible "fate" of pyruvic acid in humans?
conversion to acetyl-CoA and reduction to lactic acid in muscle
45
What effect does insulin have on entry of glucose into a red blood cell?
have no effect
46
How does glucose accumulate in the liver for storage?
active transport
47
Where is the energy coming from to convert fructose-6 phosphate + P1 to fructose-1,6 bisphosphate in step 3 of glycolysis?
The hydrolysis of ATP to ADP + P1 which is exothermic
48
What hydrolysis product of fat digestion can enter the glycolysis pathway?
glycerol
49
What effect does insulin have on glycogenesis?
activates
50
Where is glucagon made?
pancreas
51
What hormone or hormones will inhibit gluconeogenesis?
only insulin
52
What type of enzyme catalyzes step 8 of glycolysis?
mutase (isomerase)
53
What type of enzyme catalyzes step 7 of glycolysis?
kinase
54
T/F Oxidation reactions produce energy, which can be used to drive an endothermic reaction.
True
55
What is the "starting point" of glycolysis for muscle?
muscle glycogen and blood sugar after its own glycogen is used up
56
T/F glucagon will activate triglyceride hydrolysis in adipose tissue.
True
57
where are amino acids stored
they are not stored
58
T/F In fermentation in a yeast cell, the six carbon atoms of glucose are converted to three molecules of ethanol
False
59
What is the conversion of pyruvic acid to ethanol called in yeast cells?
fermentation
60
What step or steps in glycolysis represent substrate level phosphorylation?
step 7 and 10
61
T/F During strenuous exercise the muscle will use its own glycogen first and then the body's blood sugar
True
62
Why is phosphatase found only in the liver?
the liver's glycogen is only for the rest of the body and the phosphate must be removed from glucose-6-phosphate in order for the glucose to leave the liver cell
63
T/F Blood sugar refers to sucrose in the blood
False
64
The hormones glucagon and epinephrine primarily control which biochemical pathway?
glycogenolysis
65
Where does glycogenesis take place?
liver and muscle
66
When will the enzyme glycogen synthetase be most active?
when blood sugar is high
67
What is the name of the "secondary messenger" inside of a cell?
cAMP (cyclic AMP)
68
What happens when the body produces epinephrine during a crisis?
Glycogen in the muscle is broken down to glucose for major muscle work, glycogen in the liver is broken down so that glucose can move into the blood and go to the muscle, and gluconeogenesis is increased so new glucose is produced and moved to the muscle
69
How many pyruvic acids can be made from two sucrose molecules in glycolysis?
8
70
What is the purpose of the Cori cycle?
move lactic acid out of the muscle, move lactic acid to the liver, and have the liver make "new glucose" in gluconeogenesis
71
What effect does insulin have on fatty acid synthesis in adipose tissue?
activates
72
What reaction in step 6 of glycolysis is endothermic?
synthesis of a phosphate ester from inorganic phosphate
73
What is the final product (or products) of complete aerobic oxidation of pyruvic acid in yeast cells?
CO2 and H2O
74
T/F In a coupled reaction, the energy of the exothermic reaction should be larger than the endothermic reaction.
True
75
T/F Muscle cannot help regulate blood glucose levels because it lacks the enzyme necessary to convert glucose-6-phosphate to glucose
True
76
T/F glycogen stored in the liver is for blood sugar regulation while glycogen in the muscle is only for the muscle
True
77
Which compound cannot be converted back to glucose-1-phosphate?
fructose-1,6-bisphosphate
78
Which of these hormones cannot get into the cell?
insulin, glucagon, and epinephrine
79
T/F The primary purpose of digestion is produce a great deal of ATP
False
80
What effect does insulin have on the entry of glucose into a muscle cell?
activate
81
What is the "starting point" of glycolysis for all cells?
blood sugar
82
What happens when glucagon affects a liver cell?
Glucagon sits on a protein on the cell membrane of the liver cell, An enzyme inside the cell catalyzes the reaction of ATP to cAMP, and Enzymes are turned on so that phosphates can be put on glycogen synthetase and glycogen phosphorylase
83
Which step of glycolysis create an ATP?
step 7 and 10
84
How much CO2 is produced from two sucrose molecules in human glycolysis only?
0
85
T/F The same number of ATP will be produced if the cell starts with glucose or glycogen for glycolysis
False
86
What hormone or hormones will stimulate gluconeogenesis?
glucagon and epinephrine
87
Which step of glycolysis use up ATP?
Step 1 and 3
88
Which reaction in step 6 of glycolysis is exothermic?
oxidation
89
Where are triglycerides stored?
adipose tissue
90
Where is glucose stored?
liver and muscle
91
The end product of glycolysis is pyruvate (pyruvic acid). What condition inside the cell is needed to convert pyruvate to acetyl CoA for entry into the citric acid cycle?
sufficient oxygen
92
Which statement is NOT true concerning glucose in the blood?
Glucose cannot be used for energy in red blood cells.
93
Where is epinephrine made?
adrenal gland
94
What will deactivate the allosteric enzymes in glycolysis?
ATP
95
What hormone is called "The feast hormone"
insulin
96
Where does starch to glucose take place?
digestive tract
97
What is the amine base part of ATP, NAD and FAD?
adenine
98
T/F The conversion of ATP to cAMP is necessary for all hormones
False
99
What process converts lactic acid to glucose ?
gluconeogenesis
100
What hormone is used to provide the muscles with extra glucose in an emergency?
epinephrine
101
What is high blood sugar called?
hyperglycemia
102
What is the first reaction in glycolysis, which traps glucose within the cell?
phosphorylation of glucose
103
T/F The final product of digestion is CO2 and H2O
False
104
What causes muscle fatigue?
accumulation of lactic acid and acidosis
105
What is the sugar part of ATP and NAD and FAD?
ribose
106
T/F Glucose can move through a cell membrane while glucose-6-phosphate cannot.
True
107
Which is the lowest energy compound?
3CO2
108
sulfa drugs resemble the substrate need by bacteria to make folic acid. what type of inhibitor?
competitive inhibition
109
inhibitor binds to enzyme at different site than substrate but it can be removed
non-competitive inhibition
110
allosteric enzyme inhibitors are examples
non competitive inhibition
111
which inhibtion can be reversed by adding an excess of the substrate?
competitive inhibition
112
it may form a covalent bond with a side chain in the active site of the enzyme
irreversible inhibition
113
what factors affect the activity of all enzymes?
temperature
114
what is true of acetylcholine?
it contains an ester linkage, it is a neurotransmitter, it is found in the brain and in the synapse between nerves and muscles
115
Which is true of acetylcholinesterase?
It is an incredibly efficient enzyme, If permanently inhibited, it can cause over stimulation of muscles, convulsions and death, and It hydrolyzes acetylcholine into acetic acid and choline
116
Which is true of the blood clotting cascade mechanism?
The original injury will cause the formation of thromboplastin and Prothrombin is an inactive enzyme while thrombin is the active enzyme
117
Which is true of the “actual” clot?
It is formed from fibrinogen, It is a fibrous protein, and If it forms in a blood vessel it is called a thrombosis
118
Which is true of digestion?
It is mainly hydrolysis reactions
119
Which of the following is NOT a final product of digestion of carbohydrates
sucrose
120
Which of the following is not stored?
amino acids
121
Which product of digestion does not need a protein channel to get into the blood?
fatty acid
122
The products of digestion enter the blood stream from what part of the digestive tract?
small intenstines
123
What are produced from the digestion of fats and oils?
glycerol and fatty acids
124
Which is true of glycerol?
It is produced from the digestion of triglyerides, It is soluble in blood, and All cells can use it for energy
125
Which product of digestion is not soluble in blood?
amino acids and fatty acids
126
Which is MOST important for the maintenance of a constant blood sugar concentration?
synthesis and breakdown of glycogen in the liver
127
Which is true of diabetes?
insulin cannot be given orally since it would be hydrolyzed in the stomach and it can cause hyperglycemia
128
Which is true of insulin?
It is a protein and too much insulin
129
Which is true of glycogenolysis?
It is done in the liver and muscle, The enzyme glycogen phosphorylase catalyzes the reaction, Inhibited by insulin
130
What are the possible starting materials for gluconeogenesis
Some amino acids, lactic acid, glycerol
131
Which is true of glucagon?
It is protein hormone
132
Which processes are activated by insulin?
fatty acid synthesis
133
Which cells need insulin to facilitate glucose entry?
muscle cells
134
What processes are stimulated by epinephrine
glycogenolysis in the liver, glycogen is converted to glucose-1-phosphate in the muscles, and Gluconeogenesis in the liver
135
Which is true of the enzyme glycogen synthetase?
found in liver and muscle and activated when blood sugar is high
136
What happens when glucagon affects a liver cell?
Glucagon sits on
the outside of the liver cell membrane and turns on the cAMP system
137
Muscle cells have no receptor sites for which hormone?
glucagon
138
Which is true of glycogen?
It is composed of only glucose molecules and muscle uses it for major muscle work
139
Which of the following can get out of a cell using a protein channel?
glucose
140
What hormones use the cAMP system?
most protein hormones
