Biochem II Flashcards
1
Q
What is insulin addressing: the BG or energy needs of cells?
A
BG
2
Q
What is the only source of energy of RBCs?
A
Glycolysis
3
Q
What is the fuel utilization during the well fed state for the liver?
A
Glucose, AAs
4
Q
What is the fuel utilization during the well fed state for the muscles?
A
Glucose
5
Q
What is the fuel utilization during the well fed state for the heart?
A
FAs
6
Q
What is the fuel utilization during the well fed state for the adipose tissue?
A
Glucose
7
Q
What is the fuel utilization during the well fed state for the brain?
A
Glucose
8
Q
What is the fuel utilization during the well fed state for the RBCs?
A
Glucose
9
Q
What is the fuel utilization during the fasting state for the liver?
A
FAs
10
Q
What is the fuel utilization during the fasting state for the muscle?
A
FAs, ketones
11
Q
What is the fuel utilization during the fasting state for the heart?
A
FAs, ketones
12
Q
What is the fuel utilization during the fasting state for the adipose tissue?
A
FAs
13
Q
What is the fuel utilization during the fasting state for the Brain?
A
Glucose (ketones in the late fast)
14
Q
What is the fuel utilization during the fasting state for the RBCs?
A
Glucose
15
Q
What is the kcal/g for: carbs?
A
4
16
Q
What is the kcal/g for: fat?
A
9
17
Q
What is the kcal/g for: EtOH?
A
7
18
Q
What are the two types of amylase?
A
SAlivary and pancreatic
19
Q
What are the three different intestinal disaccharidases?
A
- Lactase
- Sucrase
- Maltase
20
Q
What is the enzyme that is defective in MODY?
A
Glucokinase
21
Q
What is the transporter that transports glucose from the intestines?
A
SGLT1/2
22
Q
What is the GLUT that is activated by insulin?
A
GLUT4
23
Q
What is the GLUT5 activity?
A
Passive uptake of fructose
24
Q
True or false: fructose is not regulated by insulin, or any other hormone
A
True
25
Do GLUTs 1-4 utilize passive or active transport?
Passive
26
What is the difference between hexokinase and glucokinase in terms of: location?
Hexokinase is in msot tissues, except liver
Glucokinase - only in liver and beta cells of pancrease
27
What is the difference between hexokinase and glucokinase in terms of: Km?
Low for hexokinase (high affinity)
High for glucokinase (low affinity)
28
What is the difference between hexokinase and glucokinase in terms of: Vmax?
Low for hexokinase (low capacity)
High for glucokinase (high capacity)
29
What is the difference between hexokinase and glucokinase in terms of: inducibility by insulin
Hexokinase is not affected by insulin, while glucokinase is not
30
What is the difference between hexokinase and glucokinase in terms of: Feedback inhibition by G6P
Hexokinase is inhibited
| Glucokinase is not
31
What is the main regulated step of glycolysis? What activates and inhibits it?
- Phosphofructokinase is activated via F2,6BP
| - Inhibits by ATP, citrate, pH
32
What is DHAP used for in glycolysis?
TAG synthesis
33
Glycolysis defects produces what diseases?
Hemolytic anemias
34
What is the MOA of arsenate?
Inhibits ATP production by glycolysis
35
What happens to galactose?
Converted to glucose
36
What is the cause of galactosemia? S/sx?
Defect in galactose metabolism leads to jaundice, cataracts, and liver damage early in life
37
What are the two ways in which fructose is degraded?
- Hexokinase side rxn
| - Fructokinase in the liver produces F1P, which is degraded by adolase B
38
What is the cause of benign fructosuria?
Defect in fructokinase
39
What happens with aldolase B deficiency?
Hereditary fructose intolerance
- Jaundice
- Hypoglycemia
- Hepatomegaly
40
What is the overall rxn with pyruvate dehydrogenase? Where in the cell is it?
- Produces acetyl-CoA from pyruvate
| - mitochondria
41
What are the 5 cofactors that are needed for the Pyruvate dehydrogenase complex?
NAD (niacin)
FAD (pantothenate)
B1
B5
42
What activates the Pyruvate dehydrogenase complex? Inhibits?
- Insulin activates
| - Repressed by acetyl-CoA
43
What is glycogenin?
Enzyme that attaches UDP-glucose to Y residues
44
What is the effect of insulin on liver and muscle glycogen synthase?
Activates
45
What inhibits hepatic and muscle glycogen synthase respectively?
Hepatic = glucagon and epi
Muscle = epi
46
What activates hepatic and muscle glycogen phosphorylase respectively?
Hepatic = glucagon and epi
Muscle = epi
47
What inhibits hepatic and muscle glycogen synthase respectively?
Hepatic = insulin
Muscle = insulin
48
What is the enzymatic defect in type I GSD?
Glucose-6-phosphate dehydrogenase
49
What is the enzymatic defect in type II GSD?
lysosomal glucosidase
50
What is the enzymatic defect in type III GSD?
Debranching enzyme
51
What is the enzymatic defect in type IV GSD?
Branching enzyme
52
What is the enzymatic defect in type V GSD?
Muscle phosphorylase
53
What is the enzymatic defect in type VI GSD?
Liver phosphorylase
54
What is the cause of death with Pompe's disease?
LVH
55
What is the general structure of proteoglycans?
Long Hyaluronic acid with side branches of Protein cores, with many attached glycosaminoglycans
56
What is the defective enzyme, accumulated products and s/sx of: Hurler's disease?
- Dermatan sulfate / heparine sulfate
- alpha-iduronidase
- Skeletal abnormalities, MR
57
What is the defective enzyme, accumulated products and s/sx of: Hunter syndrome
Dermatan sulfate
Heparin sulfate
-Skeletal abnormalities and MR
58
What is the defective enzyme, accumulated products and s/sx of: Sanfiloppo's disease
Heparine sulfate
| MR
59
What is the inheritance pattern of Hunter syndrome, hurler syndrome, and sanfilippo>
```
Hunter = XLR
Hurler's = AR
Sanfilippo = AR
```
60
What are the three molecules that are used as substrates for gluconeogenesis?
- Glycerol P
- Lactate
- Glucogenic amino acids
61
What is the rate limiting step of gluconeogenesis?
Pyruvate carboxylase
62
Acetyl-CoA regulates what parts of gluconeogenesis?
Carboxylase (+) and dehydrogenase (-)
63
Gluconeogenesis depends on what molecule in particular?
NAD+
64
Why does EtOH inhibit gluconeogenesis?
Lowers NAD+
65
What is the inheritance pattern of G6PD deficiency?
AR
66
What type of anemia is produced with G6PD deficiency?
Hemolytic
67
What are the three major roles of the PPP?
- liver
- PMNs = NADPH oxidase
- RBCs = defend against oxidative stress
68
What is the RBC inclusion for G6PD Deficiency?
Heinz bodies
69
What are the essential FAs?
Linoleate (9, 12)
70
Where does the synthesis of lipids begin?
Export of Acetyl-COa into the cytosol
71
What is the key reaction for lipids in the well fed state?
Acetyl-CoA carboxylase
72
What inhibits lipid import into the mitochondria?
Malonyl-CoA
73
What is the activating step of FA synthesis?
Acyl CoA synthetase
74
Why does EtOH lead to fatty liver changes?
Ethanol metabolism produces NADH, which inhibits the citric acid cycle
75
What is the role of albumin in lipid transport?
Transports in blood
76
What is the function of ApoA?
Lipid uptake into LPs
77
What is the function of ApoB?
Structural support (b100 on LDL, B48 on chylomicrons)
78
What is the function of ApoC?
For lipid release from LPs (activates LPL)
79
What is the function of ApoE?
For removal of LPs via interaction with liver receptor
80
What are the lipoproteins in chylomicrons?
b48
C
E
81
What are the lipoproteins in VLDL?
B100
C
E
82
What is the general role of LDL?
pick up cholesterol, give TAGs
83
What is the protein that extracts lipids from cells for pick up by LPs?
ABCA-1
84
What is the protein that is involved in transferring cholesterol between LPs?
Cholesteryl ester transfer protein (CTEP)
85
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86
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87
LDL oxidation can be prevented by what vitamin?
E
88
What is the backbone of HDL particles?
Apo A
89
What is familial hyperlipidemia?
Elevated LDL and cholesterol 2/2 LDL receptor deficiency
90
What is abetalipoproteinemia?
No ApoB100/48, causes lipid accumulation in enterocytes and liver, leading to extremely low serum lipids
91
What is the key step in cholesterol synthesis?
HMG-CoA
92
What is the cholesterol intermediate needed for CoQ?
Farnesylation
93
What is the shuttle utilized to transport FAs into the mitochondria?
Carnitine shuttle
94
What is the key step in FA catabolism? How is it regulated?
Carnitine shuttle across the inner mitochondrial membrane
Regulated by malonyl CoA
95
What is the most common defect in FA metabolism?
Acyl-coa dehydrogenase
96
Odd chain FAs produce what?
propionyl-CoA
