Lipids

Question 1

triacylglyderides form the main dietary lipid and are degraded to ??? and FAs

Answer 1

monoacylglycerols

Question 2

TRUE or FALSE digestive enzymes are not water soluble

Answer 2

FALSE: they ARE water soluble, lipids are not

Question 3

bile salts emulsify dietary fats in small intestine to form mixed ??? which allow TGs to be degraded

Answer 3

micelles

Question 4

intestinal/pancreatic lipases degrade ???

Answer 4

triacylglycerols/ides

Question 5

FAs and other TG breakdown products are taken up by ??? and converted back into TGs

Answer 5

intestinal mucosa

Question 6

TGs are incorporated (after being digested) with cholesterol and apolipoproteins into ???

Answer 6

chylomicrons

Question 7

TRUE or FALSE: chylomicrons can move through the lymphatic system and bloodstream to tissues

Answer 7

TRUE

Question 8

lipoprotein lipase is activated by apoC-II in ??? and converts TGs to FAs and monoacylglycerols

Answer 8

in capillaries

Question 9

bile salts/acids are amphipathic molecules made from ??? in the liver

Answer 9

cholesterol

Question 10

the hydrophobic or hydrophilic face of bile acids are used to attach to TGs?

Answer 10

hydrophobic face

Question 11

the hydrophobic or the hydrophilic face of the bile acids are pointing out to allow lipases to attack TGs?

Answer 11

hydrophilic

Question 12

Plasma lipoproteins are particles carrying TGs, cholesterol, cholesteryl esters, phospholipids, and ???

Answer 12

lipid soluble vitamins

Question 13

plasma lipoproteins are made of ???

Answer 13

apolipoproteins

Question 14

apolipoproteins can solubilise lipids and act as signals to target lipoproteins in specific tissues as well as activating ???

Answer 14

enzymes

Question 15

what are the four human plasma lipoprotein types?

Answer 15

chylomicrons, VLDL, LDL, HDL

Question 16

Receptor mediated endocytosis: the purpose of this is to minimise ??? to prevent the creation of foam cells

Answer 16

minimise LDL

Question 17

where does receptor mediated endocytosis take place?

Answer 17

in the liver

Question 18

Receptor mediated endocytosis step 1: LDL particles containing Apo-100 bind to LDL-receptor on ??? of liver cells

Answer 18

on the cell surface

Question 19

TRUE or FALSE: Receptor mediated endocytosis step 2: Following binding of LDL particles to liver cells, endocytosis is triggered

Answer 19

TRUE

Question 20

Receptor mediated endocytosis step 3: LDL is internalised in ???

Answer 20

endosome

Question 21

Receptor mediated endocytosis step 4: LDL receptor is segregated into vesicles and ???

Answer 21

recycled to cell surface

Question 22

Receptor mediated endocytosis step 5: Endosome with LDL fuses with ???

Answer 22

lysosome

Question 23

Receptor mediated endocytosis step 6: lytic enzymes in lysosome degrade apoB-100 and cholesteryl esters to release ???

Answer 23

amino acids, TGs, cholesterol

Question 24

Familial hypercholesterolaemia causes a 4 fold increase or decrease in plasma cholesterol and LDL concentrations

Answer 24

increase

Question 25

TRUE or FALSE: foam cells (macrophages) are formed by the presence of excess blood LDL which is oxidised and engulfed by macrophages

Answer 25

TRUE

Question 26

atherosclerotic plaques are formed when monocytes are attracted to oxidised ??? that aggregate and stick to the ECM, causing monocytes to differentiate into macrophage (foam cell)

Answer 26

lipoproteins

Question 27

White Adipose tissue: stores excess calories as TGs that can be used as fuel via ??? to rpoduce ATP via respiratory chain, oxidative phosphorylation

Answer 27

b-oxidation

Question 28

brown adipose tissue: stores TGs used as fuel via b-oxidation to maintain ???

Answer 28

thermogenesis

Question 29

Degradation of TGs: TG goes through hydrolysis to release glycerol backbone whilst FAs are sent to ???

Answer 29

bloodstream

Question 30

Degradation of TGs step 1: glucagon binds to a receptor, causing a G-coupled mediated reaction which activates ???

Answer 30

adenylyl cyclase

Question 31

Degradation of TGs step 2: activation of adenylyl cyclase causes the conversion of ATP to cAMP which activates ???

Answer 31

PKA (Protein Kinase A)

Question 32

Degradation of TGs step 3: PKA activates ???

Answer 32

hormone sensitive lipase

Question 33

Degradation of TGs step 4: hormone sensitive lipase mediates degradation of ??? = glycerol and 3x FAs

Answer 33

TGs

Question 34

b-oxidation of FAs is a repetitive 4-step process by which FAs are converted to ???

Answer 34

acetyl CoA

Question 35

Can 12-carbon fatty acid chains enter mitochondria directly?

Answer 35

yes

Question 36

can 14-carbon fatty acid chains enter mitochondria directly?

Answer 36

no

Question 37

longer FA chains are first linked to ??? which are then linked to carnitine to form fatty acyl carnitine molecules

Answer 37

coenzyme A

Question 38

fatty acyl carnitine enters mitochondria via ???

Answer 38

carnitine shuttle

Question 39

during FA metabolism, the acetyl group of CoA (CoA-SH) is substituted with the fatty acid acyl chain to form ???

Answer 39

fatty acyl-CoA

Question 40

Fatty Acyl-CoA synthetase is an enzyme mediating the reaction of FAs being linked to ??? to form Fatty Acyl-CoA

Answer 40

Coenzyme A

Question 41

mechanism by which FAs move through carnitine shuttle: FA chain is moved from ??? to ???

Answer 41

from CoA to carnitine

Question 42

TRUE or FALSE: inside mitochondria, the mitchondrial CoA picks up FA chain from carnitine to form Fatty Acyl-CoA again

Answer 42

TRUE

Question 43

is carnitine recycled?

Answer 43

yes

Question 44

Stage 1 of FA catabolism: ??? - the removal of successive carbon pairs, starting from carboxyl end. this pair forms acetyl-CoA

Answer 44

b-oxidation

Question 45

Stage 2 of FA catabolism: ??? enters citric acid cycle

Answer 45

acetyl CoA

Question 46

stage 3 of FA catabolism: stages 1&2 provide FADH2 and NADH which donate electrons within ??? to generate ATP

Answer 46

respiratory chain complex

Question 47

step 1 of b-oxidation of FAs: FA enters pathway, oxidation (dehydration) occurs at ??? of carbon--> FA losses a H+

Answer 47

b-site of carbon

Question 48

step 2 of b-oxidation: ??? = H2O molecules are attached

Answer 48

Hydration

Question 49

step 3 of b-oxidation: oxydation/dehydrogenation to form ???

Answer 49

NADH

Question 50

step 4 of b-oxidation: Thiolysis gives rise to ???

Answer 50

acetyl-CoA

Question 51

TRUE or FALSE: it takes a few rotations of b-odixation of FA chains to shorten enough, taking of 2 carbons at a time

Answer 51

TRUE

Question 52

b-oxidation of FAs leads to ???, CO2, H2O production

Answer 52

ATP

Question 53

b-oxidation of palmitoyl-CoA: Acyl-CoA dehydrogenase = ? FADH2, 10.5 ATP

Answer 53

7 FADH2

Question 54

b-Hydroxyacyl-CoA dehydrogenase = ? NADH, 17.5 ATP

Answer 54

7 NADH

Question 55

oxidation of unsaturated FAs involves an ??? which moves double bond and a ??? which removes a double bond

Answer 55

an isomerase, a reductase

Question 56

odd-chain FAs yield propionyl-CoA which is converted to ??? which enters citric acid cycle

Answer 56

succinyl CoA

Question 57

vitamin B12 deficiency impacts methylmalonyl-CoA metabolism, causing ???

Answer 57

spinal cord degeneration

Question 58

vitamin B12 deficiency impacts DNA synthesis in cytosol, causing ???

Answer 58

megaloblastic anaemia