Lipids

Question 1

5 classes of lipids

Answer 1

1. fatty acids
2. triacylglycerol (TAG)
3. phospholipid
4. glycolipid
5. steroids

Question 2

consequences of essential fa deficiency

Answer 2

growth retardation
reproductive failure
kidney and liver disorders
depression
ADHD

usually associated with intestinal absorption disorders

Question 3

micelles define

Answer 3

when ampiphatic lipids have their hydrophobic heads on the inside and tails on the outside and form a soluble capsule. assist large chain FAs in entering the cell l

Question 4

lipoproteins define

Answer 4

soluble proteins that combine with and help transport fats

• hydrophobic molecules inside like TAG, CE (cholesterol esters)
• hydrophilic molecules outside like PP lipids, unesterified cholesterol, apolipoproteins

Question 5

types of chylomicrons

Answer 5

a type of lipoprotein

1. VLDL (very low density - lipids&raquo_space; proteins)
2. LDL (low den - lipids > proteins)
3. HDL (high den)

Question 6

VLDL

Answer 6

produced in the liver

carries TAG, CE, cholestrol to peripheral tissues

Question 7

LDL

Answer 7

is converted from IDL, which is VLDL after TAG has been released
delivers CE and cholesterol to peripheral tissues
too much LDL in the blood will lead to obesity and atheoscelerosis

Question 8

HDL

Answer 8

removes excess cholesterol from the cell and return it to liver for elimination and for bile and hormone synthesis

Question 9

malonyl coa define

Answer 9

inhibits CPT I and II and prevents entry of long chain fa into mitochondrial intermembrane space and matrix

Question 10

CPT I deficiency

Answer 10

affects the liver

causes coma when fasting because b oxidation cannot occur and body relies on liver for glucose supply

Question 11

CPT II deficiency

Answer 11

affects skeletal and cardiac muscle, causes muscle weakness

Question 12

peroxisomes function

Answer 12

small organelles in cell cytoplasm that reduced long chain C atoms before entering the mitochondria

Question 13

examples of ketones

Answer 13

acetone
acetoacetate
3 - hydroxybutyrate

Question 14

3 main characteristics of ketone bodies

Answer 14

1. soluble in blood, does not bind to lipoprotein or albumin
2. produced in the liver when amount of acetyl coa exceeds oxidative capacity of liver
3. used by peripheral tissues and cardiac muscle, CANNOT by used by the liver

Question 15

ketonemia vs ketonuria

Answer 15

ketone bodies build up in blood and in urine

Question 16

FA degradation vs synthesis

Answer 16

Degradation:

• occurs in the mitochondrial matrix
• multiple enzymes
• NAD, FAD

synthesis:
- occurs in the cytosol of mitochondria
- ACP
- enzyme complex
- NADPH, FADH2

Question 17

sites of FA synthesis

Answer 17

• liver
• breasts
• adipose tissues

Question 18

citrate vs carnitine shuttle

Answer 18

Citrate shuttle = OAA and acetyl-CoA combined to form citrate. The citrate shuttle can then allow citrate to get OUT of the mitochondria and into the cytoplasm for fatty acid synthesis. Basically what happens after this is citrate will be cut back into Acetyl-CoA and OAA. Acetyl-CoA can then be used for synthesis of fatty acids.

Carnitine shuttle = Allow FAs to get INTO the mitochondria for fatty acid oxidation by tacking part of the FA to a molecule of carnitine, forming acyl-carnitine. The enzyme responsible for this is CPT1. The acyl-carnitine molecule then goes through a a CACT channel into the matrix and gets converted back into Fatty-acyl-CoA by CPT2. Fatty acid oxidaton then occurs.

Question 19

ACP define

Answer 19

Acyl carrier protein

this is the protein that guides the intermediates of FA synthesis

Question 20

enzyme thioesterase define

Answer 20

the thing that cleaves off FA when it is done with synthesis and release it as free molecule

Question 21

cholesterol

Answer 21

building blocks of steroid hormones
precursors of vitamin D, bile acids, etc.
synthesized in the liver and obtained through eating.
comes from acetyl CoA

Question 22

HMG -COa reducatse

Answer 22

enzyme that is essential in acetyl coa –> cholesterol synthesis

Question 23

eicosanoids

Answer 23

derived from eicosanoid acids that are synthesized throughout the body
derived from omega 3/6
control over inflammation and immunity in the body
Ex) arachnoid acid, prostaglandins, thromboxane, leukotriene

Question 24

sources od NADPH

Answer 24

PP pathway

Citrate shuttle