Anabolism & Fats

Question 1

where is the major site of fat accumulation ?

Answer 1

adipose tissue

Question 2

what is the function of adipose tissue?

Answer 2

Energy store/source
Heat insulation -adipose tissue conducts heat 1/3rd as readily as other tissues
Mechanical Cushion- surrounds internal organs & protects them from damage.

Question 3

what is special about brown adipose tissue?

Answer 3

thermogenic tissue (not important in energy storage)

Question 4

what is the most concentrated dietary fat?

Answer 4

TAGS

Question 5

how are fatty acids absorbed

Answer 5

absorbed across gut lining

Question 6

how are FA leave

Answer 6

packaged into particles for transport around body: major 1st destination after leaving gut is the LIVER.

Question 7

what percentage of dietary fuels arrive directly at liver from the gut?

Answer 7

20%

Question 8

what is the dietary fuels used for>

Answer 8

Some is used to fuel ‘housekeeping’ metabolism of liver cells
Excess glucose is stored as glycogen within the liver
Excesses of other fuels are turned to fat: De Novo Lipogenesis (DNL).

Question 9

how is DNL formed?

Answer 9

stepwise condensation of multiple 2-carbon Acetyl groups

Question 10

what do lipids need to do in order for them to be transported around the body?

Answer 10

they need to be associated with apolipoproteins, forming water-soluble lipoproteins, in order to be transported around the body

Question 11

Chylomicrons

Answer 11

carry newly-digested fats in lymphatic circulation

Question 12

HDL

Answer 12

collect cholesterol (+ small amount of TAG) from tissues, & bring it back to liver

Question 13

VLDL

Answer 13

• carry newly synthesised TAG from liver to cells of the body.

Question 14

LDL

Answer 14

– carry newly synthesised cholesterol + small amount of TAG from the liver to cells of the body.

Question 14

when a tag arrive at a target tissue what happens?

Answer 14

TAGs are again degraded into fatty acids - by Lipoprotein lipase (LPL) for transport into cells by endocytosis.

Question 15

once a fatty acids are inside a cell what happens?

Answer 15

Oxidised to generate energy
Reconverted to TAGs, which act as energy stores in a lipid vesicle

Question 16

triacylglcerol synthetase complex

Answer 16

series of enzymes and processes that are involved in the biosynthesis of triacylglycerol (TAG),

Question 17

what happens if theres too much carbohydrates?

Answer 17

Pyruvate & Citrate can form Acetyl CoA.

Question 18

what happens if theirs too much protein?

Answer 18

Some AAs: can form Acetyl CoA