Review - I Flashcards
1
Q
Energy sources of liver?
A
Fatty acids
Glucose
Amino acids
2
Q
Energy Sources of adipose tissue?
A
Fatty Acids
3
Q
Energy sources of skeletal muscle?
A
At rest - fatty acids
Exertion - glucose
4
Q
Energy sources of heart?
A
Fatty acids
5
Q
Energy sources of neurons
A
Glucose
Ketones on starvation
6
Q
Calories in carbs?
A
4/g
7
Q
Calories in protein?
A
4/g
8
Q
Calories in fats?
A
9/g
9
Q
Calories in alcohol?
A
7/g
10
Q
What is considered hypoglycemia?
A
Blood glucose < 60mg/dl
11
Q
Energy source of RBC?
A
No mitochondria, need glucose
12
Q
What does hypoglycemia cause?
A
Nerological problems
Coma
Death
13
Q
What is hyperglycemia?
A
Blood glucose > 110mg/dl
14
Q
What does hyperglycemia cause?
A
- Type II diabetes
- Problems with vasculature
- Nerve damage
- Kidney damage
- Peripheral organ damage
- Cardiomyopathy
15
Q
How many carbs does brain use per day?
A
120g
16
Q
How many carbs does skeletal muscle use per day?
A
40g
17
Q
What is lactate?
A
- Byproduct of anaerobic metabolism
- Produced by skeletal muscle during exercise
18
Q
What does glycolysis generate?
A
- Pyruvate and lactate
19
Q
What intermediate of glycolysis enters CAC?
A
AcCoA
20
Q
What conditions are required for CAC?
A
Aerobic, glycolysis will generate pyruvate and not lactate
21
Q
What modulates glycogenolysis?
A
- Mediated by epinephrine and glucagon
- Stimulated by low blood glucose
22
Q
3 stages of glycolysis?
A
- Priming
- Splitting
- Ox / Redox
23
Q
Which stage of glycolysis is ATP investment?
A
Priming
24
Q
What happens in splitting stage?
A
- F16BP generates dihydroxyacetone phosphate and glyceraldehyde-3-phosphate
- Yields 2 pyruvate molecules
25
How many pyruvate come from splitting?
2
26
What enters splitting stage?
Fructose16BP
27
What is F16BP converted to?
1. Dihydroxyacetone phosphate
| 2. Glyceraldehyde-3-phosphate
28
What is ATP earning stage in glycolysis?
Ox/redox
29
How many ATP created in glycolyis?
4
30
Net ATP gain in glycolysis?
2
31
What is created when pyruvate becomes AcCoA?
NADH
32
What is required in splitting stage?
- NAD+ used to convert glyceraldehyde-3-phosphate to 1,3 BPG
| - Conversion changes NAD+ to NADH
33
3 key glycolytic enzymes?
1. Hexokinase/Glucokinase
2. PFK-1
3. Pyruvate kinase
34
Characteristics of hexokinase?
- Present in all cell types
- Allosterically inhibited by its product (G6P)
- Constitutive enzyme – constant amount found in cells
- Low Km for glucose – high affinity
35
Glucokinase characteristics?
- Found in liver and pancreas
- Translocated between nucleus (inactive) and cytosol (active)
- F6P decreases glucokinase activity
- Glucose increases glucokinase activity
- Inducible enzyme – synthesis increased by insulin
- High Km for glucose – low affinity
- Can operate under high level of glucose in system
36
What does F6P do to glucose?
- F6P decreases glucokinase activity
| - Promotes translocation to the nucleus
37
Is gluco or hexokinase inducible?
Glucokinase
38
Gluco or hexo kinase found in all cell types?
Hexokinase
39
Gluco or Hexokinase have higher affinity?
Hexokinase, low KM
40
What are the possible fates of pyruvate
1. Alanine
2. Oxaloacetate
3. Lactate
4. CAC
41
What converts pyruvate to AcCoA?
Pyruvate dehydrogenase
42
What does Pyruvate dehydrogenase deficiency lead to?
- Accumulation of pyruvate and lactate
- Micreocephally
- Poor muscle coordination
- Retardation
43
What leads to accumulation of pyruvate and lactate?
Pyruvate dehydrogenase deficiency
44
What happens in Pyruvate carboxylase deficiency?
Inability to convert pyruvate to oxaloacetate
- Leads to increased levels of alanine, lactate, and pyruvate
- Developmental delay
- Metabolic acidosis
- Recurrent seizures
45
What converts pyruvate to oxaloacetate?
Pyruvate carboxylase
46
What causes increased levels of alanine, lactate, and pyruvate?
Pyruvate carboxylase deficiency
47
What must be regenerated for glycolysis to proceed?
NAD+
48
How does body regenerate NAD+?
1. Lactate dehydrogenase
2. Malate-aspartate shuttle
3. Glycerol-phosphate shuttle
49
What predominantly regulates NAD+ regeneration?
Lactate dehydrogenase
50
Is the Inner mitochondrial membrane impermeable to NADH or NAD?
NADH
51
What is necessary for pyruvate dehydrogenase?
Thiamine, Pantothenate, Riboflavin, or Niacin
52
What does lactate dehydrogenase do?
Convents pyruvate to lactate
53
What does lack of lactate dehydrogenase cause?
- Lack of NAD+ need in glycolysis
| - Cannot maintain exercise levels
54
What is lactate formation dependent on?
NADH levels in cell
55
What does hexo/gluco kinase work on?
Glucose to G6P
56
PFK1 work on?
F6P to F16BP
57
What does pyruvate kinase work on?
Phosphoenol pyruvate to Pyruvate
58
What do deydrogenases generate?
NADH
59
Inhibitors/activators of glucose kinase
Inhibit: F6P
Activate: Glucse, synthesis increase by insulin
60
How does pyruvate become alanine?
Transamination
61
What does pyruvate dehydrogenase require?
NAD+
62
What do low levels of NADH cause?
Decrease lactate formation
63
What is oxygen required for?
1 - Reoxidation of mitochondrial NADH formed from PDH
| 2- Reoxidation of NADH formed by shuttles
64
What is required to create glucose from galactose?
Galactokinase
| Galactose16 uridyltransferase
65
What accumulates in galactosemia?
1. Galacitol
| 2. Galactose1P
66
Which form of galactosemia is most common and severe?
Galactose1P uridyltransferase
67
What is symptom of galactosemia?
Cataracts
68
How is galactosemia inherited?
Autosomal recessive
69
What can you not give galactosemic child?
Milk
70
How is fructose intolerance inherited?
Autosomal recessive
71
Symptoms of fructose intolerance?
Hypoglycemia
Jaundice
Vomiting
Hepatic failure
72
What does aldolase B deficiency cause?
Fructose intolerance
73
What accumulates in fuctose intolerance?
Fructose
Uric Acid
Lactic acid
