Ch 11: Lipid and Amino Acid Metabolism

Question 1

MECHANICAL digestion of lipids occurs

Answer 1

primarily in the stomach

Question 2

CHEMICAL digestion of lipids occurs _____

and is facilitated by _______

Answer 2

small intestine

bile, pancreatic lipase, colipase, and cholesterol esterase

Question 3

Micelles are formed by

Answer 3

digested lipids for absorption or to be absorbed directly by body

Question 4

Short-chain fatty acids are

Answer 4

absorbed as micelles and assembled into chylomicrons for release into the lymphatic system

Question 5

Long-chain fatty acids are

Answer 5

absorbed as miscelles and assembled into chylomicrons for release into the lymphatic system

Question 6

Hormone-sensitive lipase

Answer 6

lipids are mobilized from adipocytes by this

Question 7

Lipoprotein lipase

Answer 7

lipids are mobilized from lipoproteins by this

Question 8

Chylomicrons (lipid transport)

Answer 8

transport mechanism for dietary triacylglycerol molecules and are transported via the lymphatic system

Question 9

VLDL (lipid transport)

Answer 9

transports newly synthesized triacylglycerol molecules from the liver to peripheral tissues in the bloodstream

Question 10

IDL (lipid transport)

Answer 10

VLDL remnant in transition between triacylglycerol and cholesterol transport; it picks up cholesterol for use by tissues

Question 11

LDL (lipid transport)

Answer 11

primarily transports cholesterol for use by tissues

Question 12

HDL (lipid transport)

Answer 12

involved in the reverse transport of cholesterol

Question 13

Apoproteins (lipid transport)

Answer 13

control interactions between lipoproteins

Question 14

Cholesterol may be obtained through

Answer 14

dietary sources or through de nova synthesis of the liver

Question 15

De nova synthesis

Answer 15

synthesis of complex molecules from simple molecules such as sugar or amino acids

Question 16

key enzyme in cholesterol biosynthesis is

Answer 16

HMG-CoA reductase

Question 17

LCAT catalyzes the formation of

Answer 17

cholesteryl esters for transport with HDL

Question 18

CETP catalyzes the transition of

Answer 18

IDL to LDL by transferring cholesterol esters from HDL

Question 19

Fatty acids are

Answer 19

carboxylic acids, typically with a single long chain, although they can be branched

Question 20

Saturated fatty acids have

Answer 20

no double bond character between carbons

Question 21

Unsaturated fatty acids have

Answer 21

one or more double bonds

Question 22

Fatty acids are synthesized in the

Answer 22

cytoplasm from acetyl-CoA transported out of the mitochondria

Question 23

Fatty acid from acetyl-CoA Synthesis includes 5 steps _____

that are repeated 8x to form palmitic acid, the only fatty acid that humans can synthesize

Answer 23

activation
bond formation
reduction
dehydration
second reduction

Question 24

Fatty acid oxidation occurs in the ______ following transport by the _______

Answer 24

mitochondria

carnitine shuttle

Question 25

Uses cycles of oxidation, hydration, oxidation, and cleavage

Answer 25

B-oxidation

Question 26

branched and unsaturated fatty acids require

Answer 26

special enzymes

Question 27

unsaturated fatty acids use ____ and an additional _____ during cleavage

Answer 27

isomerase

reductase

Question 28

Ketone bodies form (ketogenesis) during

Answer 28

a prolonged starvation state due to excess acetyl-CoA in the liver

Question 29

Ketolysis regenerates

Answer 29

acetyl-CoA for use as an energy source in peripheral tissues

Question 30

during prolonged starvation, the brain can derive up to 2/3 of it’s energy from

Answer 30

ketone bodies

Question 31

protein digestion occurs primarily in the

Answer 31

small intestine

Question 32

Catabolism of cellular proteins occurs only under

Answer 32

conditions of starvation

Question 33

Carbon skeletons of amino acids are used for

Answer 33

energy, either through gluconeogenesis or ketone body formation

Question 34

Amino groups are fed into the ____ for excretion. The fate of the side chain depends on its chemistry

Answer 34

urea cycle