Review Flashcards
1
Q
What converts pyruvate into acetyl CoA?
A
Pyruvate dehydrogenase
2
Q
What is the abbreviation for Pyruvate Dehydrogenase?
A
PDH
3
Q
What are the 5 cofactors required by pyruvate dehydrogenase? (Names, not vitamin numbers)
A
Thiamine Riboflavin Niacin Pantothenate Lipoase
4
Q
What are the 4 vitamins that provide the cofactors for the conversion of pyruvate to acetyl CoA?
A
Vitamin B1, B2, B3, B5
5
Q
Why can’t glucose be made from fat or acetyl CoA?
A
The reaction involving pyruvate dehydrogenase has a very negative delta G, making it irreversible
6
Q
What is the yield from glycolysis?
A
2 pyruvate
7
Q
1 pyruvate yields what?
A
1 acetyl CoA
8
Q
In the TCA cycle, 1 acetyl CoA yields what?
A
3 NADH, 1 FADH2, 1 GTP
9
Q
What is the yield of 1 NADH in the ETC?
A
About 3 ATP
10
Q
What is the yield of 1 FADH2 in the ETC?
A
About 2 ATP
11
Q
What is the yield of the products of one round in the TCA cycle, then passing through the ETC?
A
3 NADH X 3 = 9
1 FADH2 x 2 = 4
12
Q
For the conversion of pyruvate to acetyl CoA, TPP is added as ___.
A
Thiamine
13
Q
For the conversion of pyruvate to acetyl CoA, FAD is added as ___.
A
Riboflavin
14
Q
For the conversion of pyruvate to acetyl CoA, NAD+ is added as ___.
A
Niacin
15
Q
For the conversion of pyruvate to acetyl CoA, CoA is added as ___.
A
Pantothenate
16
Q
Where does the conversion of pyruvate to acetyl CoA occur?
A
In the mitochondria
17
Q
Where are the 5 places that energy comes off of the TCA cycle?
A
- NADH - from isocitrate, via isocitrate dehydrogenase
- NADH - from alpha-ketoglutarate, via a-keto dehydrogenase
- NADH - from malate, via malate dehydrogenase
- GTP - from succinyl-CoA, via succinyl-CoA dehydrogenase
- FADH2 - from succinate, via succinate dehydrogenase
18
Q
Where does CO2 come off the TCA cycle?
A
- Isocitrate, via isocitrate dehydrogenase complex
2. Alpha-ketoglutarate, via a-ketog dehydrogenase complex
19
Q
The alpha-ketoglutarate complex is remarkably similar to which other complex?
A
Pyruvate dehydrogenase complex
20
Q
The reactions of the second half of the TCA cycle are similar to what?
A
Lipid synthesis reactions
21
Q
What is amphibolic?
A
Having both anabolic and catabolic natures (specifically the TCA cycle)
22
Q
What is an anapleurotic reaction?
A
One that replenishes pathway intermediates
23
Q
Where is the most important anapleurotic reaction found? What does it do?
A
In the liver
Pyruvate carboxylase is used to produce OAA
24
Q
What allosteriacally activates pyruvate carboxylase?
A
Acetyl CoA
25
What is the feedback inhibitor for pyruvate dehydrogenase?
Acetyl CoA
26
There is a build of of acetyl CoA, what will be slowing down as a result of feedback?
Pyruvate dehydrogenase
27
Pyruvate carboxylase in the liver produces what for the TCA cycle?
Oxaloacetate (OAA)
28
Pyruvate carboxylase requires which cofactor?
Biotin
29
What does a mutation in fumarase cause?
Leiomas in the kidney and smooth muscle
30
What does a mutation in succinate dehydrogenase cause?
Pheochromocytomas in the adrenal glands
31
Where does glycolysis occur?
In the cytoplasm of the mitochrondria
32
Where does the TCA cycle occur?
In the matrix of the mitochondria
33
Where is pyruvate dehydrogenase found?
In the matrix of the mitochondria
34
How many proteins does the mitochondrial genome code for?
13
35
Which complex of the ETC has the most subunits?
Complex 1
36
Which complex of the ETC doesn't pump protons?
Complex 2
37
Which complex of the ETC only pumps 2 protons?
Complex 4
38
Which part of the ETC can cause apoptosis?
Cytrochome C
39
What are the two diseases caused by mitochondrial genome mutations?
Leber's hereditary optic neuropathy
| Myoclonic epilipsy and ragged-red fiber
40
Why is the hydroxyl radical the most dangerous?
Reacts will all biomolecules via either hydrogen abstraction or addition
41
What damage do hydroxyl radicals cause if they react with biomolecules?
Lipid peroxidation, causing cellular swelling and Ca++ influx
DNA strand breakage
Protein oxidation and degradation
42
How does the polyol pathway contribute to reactive oxidative species?
It depletes NADPH that is needed to neutralize it
43
An excess in glucose can cause what, due to the polyol pathway?
Increased sorbitol production, leading to increased fructose production
44
What are the two chain breaking anti-oxidant vitamins?
Vitamin C
| Vitamin E
45
What dos vitamin A do as an anti-oxidant vitamin?
It is a singlet oxygen scavenger
46
What is the starting material for retinal?
Beta-carotene
47
What binds to opsin?
11-cis-retinal
48
How is 11-cis-retinal converted to trans?
By visible light
49
What vitamin is retinal?
A1
50
When retinal and opsin bind, what is formed?
Rhodopsin
51
What are the symptoms of vitamin A toxicity?
```
Nausea
Liver damage
Birth defects
Weight loss
Joint pain
```
52
Cholecalciferol is which vitamin?
Vitamin D3
53
What is the activated steroid hormone that regulates the genes required for bone metabolism?
1,25 dihydroxycholecalciferol (1,25 dihydroxyvitamin D3)
54
What is the vitamin D hydroxylase in the liver?
25-hydroxylase
55
What is the vitamin D hydroxylase in the kidney?
1-hydroxylase
56
What diseases are caused by vitamin D deficiency?
Rickets
| Osteomalacia
57
What issues can be present with vitamin D deficiency>
Enlarged growth plates
| Defective remineralization of bone
58
What is vitamin K involved in?
Blood clotting
59
Vitamin K is the cofactor for which carboxylase?
Vitamin K dependent carboxylase
60
To be functional, what must occur to vitamin K?
Has to be converted to an epoxide and back again
61
What drug disrupts the conversions of vitamin K?
Warfarin
62
What does folate facilitate?
Methyl group transfers during nucleotide synthesis (especially in a fetus)
63
What disease does a lack of folate cause?
Spina bifida
64
Folate is important in nucleotide metabolism, so which cells are most affected?
Rapidly dividing cells
| Ex. gut, bone marrow, fetus
65
What does folate deficiency contribute to in adults?
Megaloblastic anemia
66
What is vitamin B12?
Cobalamin
67
What makes vitamin B12?
Anaerobic bacteria in the gut
68
Where do the bacteria for vitamin B12 come from?
Meat and dairy products
69
What is required by vitamin B12?
An intrinsic factor from gastric parietal cells
70
Where is vitamin B12 stored after being released into the blood stream?
In the liver
71
What is the cause of pernicious anemia?
Loss of gastric cells that produce the intrinsic factor that helps B12 absorption
72
What are the signs of pernicious anemia?
Pale conjunctiva
| Glossitis (smooth, red tongue)
73
What happens to red blood cells with pernicious anemia?
They are larger than they should be
| Clumpy
74
Vitamin B12 is the source of ___ for H+ exchanges?
Free radicals
75
How many reactions require B12? In what are they involved?
12
| Amino acid synthesis
76
What disease is caused by copper overload?
Wilson's disease
77
In Wilson's disease, copper accumulates in what tissues?
Liver
Eyes
Brain
78
What diseases does iodine deficiency cause?
Goiter
| Cretinism
79
What does iodine do?
Takes part in thyroxine and triiodothyroxine synthesis
80
What is the backbone for sphingolipids?
Serine
81
Deficits in sphingolipids cause problems in what tissues?
Nervous tissues
82
What is attached to serine to form sphingolipids?
Palmitate
83
What are the functions of free fatty acids?
Metabolic fuel
Precursors for other lipids
Membrane anchor
84
What are the functions of sphingolipids?
Membrane structure
Signal transduction
Surface antigens
85
What are the functions of eicosinoids?
Signal transduction
86
Eicosinoids are little hormones involved in what?
Inflammation
87
What is the biggest product of cholesterol?
Bile salts
88
What are sterols?
Anything derived from cholesterol
89
What are the functions of sterols?
Membrane structure
Hormones
Detergents
Vitamins
90
What are the functions of prenols?
Metabolic intermediate
Regulation
Cofactors
Vitamins
91
Where can prenols be founs?
Vitamin A
| may be found in other lipid soluble vitamins
92
What are two example of saturated fats?
Myristic acid
| Palmitic acid
93
What do saturated fats do to the body?
Elevate cholesterol levels
94
What is an example of a monosaturated fat?
Oleic acid
95
What do monosaturated fats do in the body?
Lower LDL cholesterol levels
96
What is an example of a monsaturated fat?
Oleic acid
97
What are the two types of essential fatty acids?
Linoleic acid
| Linolenic acid
98
What is an example of a polyunsaturated fat?
Linoleic acid
99
Linoleic acid is a precursor to what?
Arachidonic acid
100
What type of fat isn't as bad for you?
Monosaturated
101
What is the most important omega 3 fatty acid?
Linolenic acid
102
What does linolenic acid do for the body?
Reduced BP and heart rate
Anti-arrhythmic
Anti-thrombotic
Anti-inflammatory
103
What are the 2 classifications of membrane lipids?
Phospholipids
| Glycolipids
104
Most membrane lipids have what type of backbone?
Glycerol
105
If there is a sugar attached to a sphingosine backbone with a fatty acid, what type of sphingolipid is it?
Glycolipid - ex. blood antigens
106
Prenols include what two vitamins?
A
| K
107
What type of molecules are prenols?
Signaling molecules
108
Where are cardiolipins found?
Inner mitochondrial membrane
109
Where are cardiolipins most abundant?
Cardiac muscle
110
Abnormal cardio lipins have been associated with what 2 diseases?
Alzheimers
| Parkinsons
111
What is barth's syndrome?
X-linked disorder caused by a defect in cardio lipin processing protein
112
About 50% of phospholipids in cardiac muscle are what?
Plasmalogens
113
What is released from basophils and stimulates platelet aggregation and seratonin release?
Platelet activating factor (PAF)
114
Arachidonic acid is a precursor to what 2 things?
Prostaglandins
| Lumboxanes
115
What acts as a reservoir for aracidonic acid?
Phospholipases
116
What is a type of phospholipid that doesn't come from fat?
Sphingolipids
117
Where are sphingolipids primarily found?
Nerve tissue/myelin sheath
118
Sphingolipids are about ___% of human lipids?
25%
