metabolism A Flashcards
1
Q
which enzyme is found only in the liver
A
phosphatase
2
Q
why is phosphatase found only in the liver
A
glycogen in the liver must provide glucose for the entire body
3
Q
what does phosphatase do
A
convert glucose-6-phosphate to glucose
4
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
glucagon is trying to raise blood sugar
5
Q
what compounds can be converted to glucose in gluconeogenesis
A
lactic acid
glycerol
some amino acids
6
Q
which cells need insulin for glucose entry
A
muscle cells
liver
adipose
7
Q
if glycogen synthetase were allosteric, what effect would ATP have on it
A
active
excess ATP means that there is no need for glycolysis
glucose should be stored as glycogen
8
Q
what happens to MOST of the glucose-6-phosphate in liver versus muscle tissue
A
- In muscle it is used for energy, in liver it is converted to glucose to be transported by the blood to other cells
- they can both be converted to glycogen if not needed
Liver uses fatty acids for most of its energy needs
9
Q
Exothermic reactions
A
- oxidation glucose to CO2 H2O
- succinyl-CoA–> succinic acid & coenzyme A
- GTP –> GDP & Pi
- hydrolysis of acetyl-CoA
- hydrolysis of glucose-6-phosphate to glucose
- CH3CH2OH to CH3CH=O
10
Q
cannot be converted back to glucose-1-phosphate
A
fructose-1,6-biphosphate
step # 3 in glycolysis is irreversible
11
Q
the purpose of the cori cycle is
A
move lactic acid out of the muscle
have the liver provide the muscle with “new” glucose
12
Q
oxidation reactions
A
are always exothermic
13
Q
oxidation of glucose to CO2 H2O
A
exothermic
14
Q
glycogen synthesis
A
endothermic
15
Q
ADP & Pi –> ATP
A
endothermic
16
Q
Conversion of glucose-1-phosphate to glucose-6-phosphate
A
endothermic
17
Q
succinyl-CoA –> sussinic acid & coenzyme A
A
exothermic
18
Q
GTP –> GDP & Pi
A
exothermic
19
Q
all anabolic reactions
A
endothermic
20
Q
photosynthesis
A
endothermic
21
Q
hydrolysis of acetyl CoA
A
exothermic
22
Q
formation of glucose-6-phosphate from glucose
A
endothermic
23
Q
hydrolysis of glycogen to glucose
A
exothermic
24
Q
hydrolysis of glucose-6-phosphate to glucose
A
exothermic
25
CH3CH2OH to CH3CH=O
exothermic
26
does NOT occur in "fight or flight"
epinephrine crosses cell membrane to stimulate glycogenolysis
epinephrine cannot enter the cell
27
which occurs during "fight or flight"
1. glycogen is converted to glucose-1-phosphate in the muscles
2. epinphrine stimulate the production of cyclic-AMP in muscle cells
3. cAMP causes the glycogen synthetase to be deactivated
4. glycogenolysis is stimulated
28
proteins (polypeptides)
Glucagon
Insulin
Lactic acid dehydrogenase
29
polysaccharides
glycogen
30
can move through a cell membrane
glucose
| cortisol
31
can stimulate fatty acid synthesis from acetyl CoA
insulin
32
stimulate the immediate conversion of glycogen to glucose-1-phosphate in the liver
Glucagon
33
stimulate the conversion of certain amino acids to glucose in gluconeogenesis
cortisol
Glucagon
34
Reverse of the other
1. anabolism & catabolism
2. glycogenolysis & glycogenesis
3. photosynthesis & complete oxidation of glucose
35
produces the most ATP in glycolysis
fructose-1,6-biphosphate
there are already 2 phosphates on the molecule
36
produces the least ATP in glycolysis
glucose
37
in anaerobic exercise the pH of the muscle will
decrease
acidosis
38
which processes needs alot of ATP
muscle activity
synthesizing protein from amino acid
active transport
all anabolic reactions
39
reactions can be coupled so
one reaction drives the other
40
hydrolysis of glucose-1-phosphate to glucose give 5 kcal/mole
fructose-6-phosphate to fructose give 3.8
glucose-6-phosphate to glucose 3.8
creatine phosphate to creatine give 10.3
ATP to ADP and Pi gives 7.5 kcal/mol
which reactions would be exothermic or favorable
creatine phosphate & ADP to creatine & ATP
41
get 3.8 from fructose-1-P to fructose need 7.5 for ADP & Pi to ATP
total needed 3.7
42
get 10.3 from creatine-phosphate to creatine need 7.5
| ADP & Pi to ATP
total get 2.8
43
get 3.8 from glucose-6-P to glucose need 10.3 for creatine to creatine-phosphate
total need 6.5
44
inhibits glycogenesis in the liver
| hormone
Glucagon
45
stimulates glycogenolysis in the muscle
| hormone
Epinephrine
46
stimulates entry of glucose into a muscle cell
| hormone
insulin
47
inhibits gluconeogenesis
| hormone
Insulin
48
stimulates entry of glucose into brain cells
| hormone
none
49
Glycogen to glucose-1-phosphate
| enzyme catalyzes
Phosphorylase
50
Glucose-1-phosphate to glucose-6-phosphate
| enzyme catalyzes
mutase
51
GLucose & ATP to glucose-6-phosphate & ADP
| enzyme catalyzes
kinase
52
Glucose-6-phosphate to glucose
phosphatase
53
if glycolysis is taking place in a red blood cell, where is the starting point
glucose
54
the purpose of converting pyruvic acid to lactic acid is to regenerate
NAD
55
which cannot move through a cell membrane
```
glycogen
glucose-1-phosphate
protein hormones
epinephrine
polypeptides
```
56
can move through cell
```
glucose
CO2
galactose
steroid hormones
fatty acids
glycerol
amino acids
```
57
glycogen
cannot move through cell
polysaccharide
58
glucose-1-phosphate
cannot move through cell
phosphate prevents moving through membrane
59
protein hormones
cannot move through cell
60
epinephrine
cannot move through cell
61
polypeptides
cannot move through cell
62
true of insulin
inhibits glycogenolysis
stimulates entry of glucose into muscle tissue & liver tissue
63
FALSE of insulin
1. too much insulin will result in hyper glycemia
2. stimulates entry of glucose into brain cells
3. it stimulates gluconeogenesis
64
the cAMP system is used for
mainly protein hormones
65
digestion is mainly a process of
hydrolysis
66
which process is MOST important in the maintenance of a constant blood glucose concentration
synthesis and breakdown of glycogen in the liver
67
TRUE diabetes
1. it will occur when there are not enough insulin receptor sites
2. it will occur when not enough insulin is secreted (released) by the pancreas
3. kidneys will excrete large amounts of water in order to remove excess sugar from the blood
68
FALSE of diabetes
1. occur when not enough insulin is produced by the liver
2. can cause hyperglycemia
3.
69
when a phosphate is added to an enzyme to either activate it or deactivate it
covalent modification
70
what is called the "famine" hormone
famine= glucagon
71
"feast" hormone
feast=insulin
72
where is galactose converted to glucose
liver
73
the breakdown of food molecules into simpler chemical substances that can be absorbed by the body is called
digestion
74
what substance is secreted from the adrenal glands in response to low blood sugar levels, strenuous exercise or stress
epinephrine
adrenaline
75
what type of enzyme is needed to convert pyruvic acid to acetalaldehyde in fermentation
decarboxylase
76
starting with glucose, which steps in glycolysis are using up ATP
```
#3
#1
```
77
where does digestion start for proteins
stomach
78
where does digestion start for carbohydrates
mouth
79
where does digestion start for lipids [not metabolism]
small intestines
80
when epinephrine reaches the receptor cell on
muscle cells
81
when empinphrine reaches the receptor cell on muscle cells, it stimulates the process called
glycogenolysis
82
what happens when glucagon affects a liver cell
glucagon turns on adenyl cyclase which stimulates the reaction ATP to cAMP
kinase enzymes are turned on so phosphate can be put on glycogen synthetase and glycogen phosphorylase
83
what are the effects of glucagon
1. glucose is converted to glycogen in the liver
b. glycogenolysis is stimulated in the liver and muscle
c. gluconeogenesis is inhibited
d. none
none
84
conversion of glucose-6-phophate to fructose-6-phosphate needs an isomerase enzyme and ATP for energy
false
no ATP is needed
85
RBCs do not have mitochondria so they must get all their energy from glycolysis
true
86
in a reaction that is energetically unfavorable, the energy of the products is more than the energy of the reactants
true
87
oral anti-diabetic drugs are similar to insulin in their structure
false
they are not proteins
proteins would be digested in the stomach
88
oral anti-diabetic drugs help with only some types of diabetes
they help increase the release of insulin from the pancreas
| but no the original amount of insulin produced
89
Glucose 1-phosphate
Mutase
| Isomers see
90
Glucose6-phosphate---> liver only
Phosphatase
Glucose--> to blood
91
Glucose 6-phosphate--ATP/ADP--> glucose.
Kinase
ATP-->ADP
Blood
92
Glucose 6-phosphate fructose 6-phosphate
Isomerase
93
Fructose 6-phosphate --ATP ADP--> fructose 1,6-biphosphate
Allosteric
Inhibited by ATP
Kinase
94
NAD
| NADH
Dehydrogenase
95
-CO2
Decarboxylase
96
ATP
| ADP
Kinase
97
Steps 7+ 10
Substrate level phosphorylation
98
Oxidative pathways
Kreb cycle
| Aerobic
99
Muscle..
Anaerobic
100
Yeast
Anaerobic
Fermentation
101
Allosteric
Inhibited ATP
Using up ATP
Putting P on
Against gradient
102
Step 6
Glyceraldehyde 3-phosphate -P. NAD NADH-> 1,3 biphosphoglyceric acid
Coupling
Endothermic
Putting P on
