Metabolism 101 Flashcards Preview

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Flashcards in Metabolism 101 Deck (25):
1

Long chain fatty acid degradation site

Transport of Fatty Acyl-CoA from the cytosol into the mitochondria (via carnitine shuttle transport)

2

Systemic Primary carnitine deficiency

Inherited defect in transport of Long chain fatty acids into the mitochondria (defect in carnitine shuttle)
Causes weakness, hypotonia and hypoketotic hypoglycemia

3

Fatty acid synthesis rate limiting enzyme

Acetyl CoA carboxylase

4

Fatty acid oxidation rate limiting enzyme

Carnitine acyltransferase I

5

Ketone bodies

Acetone, acetic state and beta hydroxybutyrate

6

Causes of increased ketone body synthesis

Ketoacidosis: oxaloacetate is depleted for gluconeogenesis
Alcoholism: excess NADH shunts oxaloacetate to malate
BOTH PROCESSES--> increased acetyl CoA
Acetyl CoA converted to acetoacetate and beta hydroxybutyrate in liver and delivered to extrahepatic tissues

7

Fuel use after eating: Fed state

Glycolysis and aerobic respiration

8

Fatty acid synthesis site

Transport citrate from mitochondria to the cytosol (via citrate shuttle)
Occurs in liver, lactating mammary glands and adipose tissue

9

Fuel Use: starvation days 1-3

Hepatic glucogenolysis
Adipose release of FFA
Energy use of FFA in muscle and liver
GLYCOGEN IS DEPLETED AFTER ONE DAY OF FASTING

10

Fuel Use: starvation 3+ days

Adipose stores: ketones become the main source of energy for the brain
After adipose is depleted, vital protein is degenerated -->organ failure and death
Excess adipose stores determine length of survival

11

Cholesterol synthesis

Acetyl CoA precursor
Enzyme: HMG CoA reductase

12

Lipoprotein Lipase

Degradation of triglycerides circulating in chylomicrons and VLDL's
On vascular endothelial surface

13

Hepatic TG lipase

Degradation of TG remaining in IDL

14

Hormone sensitive lipase

Degredation of TG's stored in adipocytes

15

LCAT

Takes "nascent"/immature HDL and adds cholesterol to it to form a mature HDL particle

16

Cholesterol ester transfer protein (CETP)

Mediates transfer of cholesterol esters to other lipoprotein particles
Takes cholesterol esters from mature HDL, transfers them to VLDL, IDL and LDL in exchange for triglycerides

17

ApoE

Mediates remnant uptake
Chylomicrons, chylomicrons remnant, VLDL, IDL and HDL
EVERYONE (besides LDL) gets ApoE

18

ApoA-I

Activates LCAT
Chylomicrons and HDL

19

ApoC II

Lipoprotein lipase cofactor
Chylomicron, VLDL and HDL

20

ApoB48

mediates chylomicron secretion
Chylomicron/chylomicron remnant

21

ApoB 100

Binds LDL receptor
VLDL, IDL and LDL

22

Familial dyslipidemia type I

Autosomal recessive
LPL or ApoCII deficiency
Increased TG, chylomicrons and cholesterol
Clinical s/s: pancreatitis, hepatosplenomegaly, pruritic xanthomas
Creamy layer of supernatent

23

Familial hypercholesterolemia
Type II

Autosomal dominant
Absent or defective LDL receptors
Increased LDL, cholesterol
Heterozygotes: 300 cholesterol
Homozygous: 700+ (very rare)
Accelerated atherosclerosis: MI before age 20, tendon xanthomas, corneal arcus

24

Hypertriglyceridemia
Type IV

Autosomal dominant
Hepatic overproduction of VLDL
Increased VLDL, TG
Hypertriglyceridemia-->acute pancreatitis (>1000 for TG's)

25

Abetalipoproteinemia

Auto recessive
Decreased ApoB48 and ApoB100
MTP mutation
S/s steatorrhea, night blindness, vit deficiency: water soluble
Tx: vitamin E