Biochem-Ch. 17

Front 1

Which of the following is True of the properties of triacylglycerols?

A- They are chemically reactive
B- They readily diffuse across cell membranes
C- They are soluble in water
D- They generate more energy than the same weight of carbohydrate

Back 1

D. They have an energy of complete oxidation more than twice that for the same weight of carbohydrate

Front 2

Ingested triacylglycerols are emulsified in the intestine by
A- Chylomicrons
B- bile salts
C- lipases
D- apolipoproteins

Back 2

B

Front 3

what effect does the hormone glucagon have on fatty acid metabolism?

A- it triggers the mobilization of stored fats
B- it triggers the conversion of triacylglycerols to glucose
C- It triggers the conversion of glucose into triacylglycerols
D- It triggers the storage of triacylglycerols

Back 3

A

Front 4

Glucagon, along with epi, is secreted in response to low blood glucose levels and activates a cascade of events that leads to the mobilization of triacylglycerols in adipose tissue. IN this cascade, _________ ________ is activated, causing the hydrolysis of triacylglycerols into fatty acids, which enter the bloodstream for transport to other _______

Back 4

triacylglycerol lipase
tissues

Front 5

Which of the following is TRUE of acyl-COA synthetases?

A- They hydrolyze pyropphsophate
B- They are located in the mitochondrial matrix
C- They activate fatty acids for oxidation
D- They join fatty acids to CoA by a phosphoester linkage

Back 5

C

Front 6

acyl-CoA synthetases attach coenzyme A to ______ ______, turning them into fatty acyl-CoA esters that are activated for oxidation in the mitochondria

Back 6

fatty acids

Front 7

Carnitine is used for...

Back 7

transport of fatty acids across the inner mitochondrial membrane.

Front 8

carnitine is used for the transport of long-chain fatty acids (with ____ or more carbons) through the inner mitochondrial membrane into the mitochondrial matrix, where they undergo _____ _________. Activated fatty acid-CoA esters formed in the intermembrane space of the mitochondria cannot cross the inner mitochondrial membrane intact. Instead, the fatty acyl group is transiently atached to the _______ group of _______ to form fatty acyl carnitine, which enter the matrix by facilitated diffusion through the acyl-carnitine/carnitine transporter. Once inside the matrix, the fatty acyl group is enzymatically transferred from _______ to _____ to activate the fatty acid for beta oxidation.

Back 8

14
beta oxidation
hydroxyl
carnitine
carnitine
CoA

Front 9

the 3rd carbon is the ____ carbon

Back 9

beta
(carbonyl, alpha, beta)

Front 10

the first step of beta-oxidation, catalyzed by acyl-CoA dehydrogenase, involves

A- the formation of a double bond
B- the formation of a carboxyl group
C- the formation of a hydroxyl grouo
D- the input of H20

Back 10

A

Front 11

acyl-CoA dehydrogenase removes two hydroges from the ____ and ____ carbons of a fatty acyl-CoA, creating a ____ double bond between those two carbon atoms.

This double bond is needed for the action of the next enzyme in the beta-oxidation pathway, ______ ______, which adds H2O across this double bond.

Back 11

alpha, beta
trans
enoyl-CoA hydratase

Front 12

so what enzyme adds a double bond?

Back 12

acyl-CoA dehydrogenase

Front 13

what enzyme adds whater?

Back 13

enoyl-COA hydratase

Front 14

each beta-oxidation cycle generates ___ molecule of NADH, ____ molecule of FADH2, and ___ moleucle of acetyl-COA, except for the last beta-oxidation cycle, which results in ___ molecules of acetyl-CoA.

Therefore, a 16-carbon saturated fatty acid will be completely oxidized by ____ beta-oxidation cycles, generating ____ molecules lf Acetyl-CoA

Back 14

1,1,1,2
7, 8

Front 15

what enzyme is needed for fatty acids that contain CIS double bonds? (the CIS fatty acid must be converted to the trans configuration in order for beta-oxidation to continue)

The enoyl-CoA hydratase step of the beta-oxidation cycle will act ONLY upon a _____ double bond.

An 18 carbon fatty acid chain with a double bond at carbon 9 can undergo ______ passes through the fatty acid oxidation cycle to yield three molecules of acetyl-CoA and the coenzyme A ester of a 12 carbon unsaturated (at carbon 3) fatty acid.

Enoyl-CoA isomerase isomerizes the CIS-3-enoyl-COA to the ____-___ 2- enoyl-CoA, which can be oxidized ____ more times to yield ____ additional molecules of acetyl-CoA

Back 15

enoyl-COA isomerase
trans
3
Trans
5
6

Front 16

Enoyl-CoA isomerase is needed for the complete Beta-oxidation of

A- unsaturated fatty acids with cis double bonds
B- odd-numbered fatty acids
C- saturated fatty acids
D- unsaturated fatty acids with trans double bonds

Back 16

A

Front 17

Enoy-CoA isomerase changes the cis double bond to a trans double. the ______ ______ can only work on the trans configuration.

Back 17

enoyl-CoA hydratase

Front 18

The propionyl-CoA produced by beta-oxidation of long-chain ODD-numbered fatty acids enters the TCA as

A- succinyl-CoA
B- Malonyl-CoA
C- oxaloacetate
D- acetyl-CoA

Back 18

A

Front 19

After Triacylglycerols are hydrolyzed into free fatty acids and glycerol, how is glycerol used for energy?

A- it undergoes Beta-oxidation
B- It enters the glyoclysis pathway
C- It enters the TCA
D- it is converted to ketone bodies

Back 19

B

Front 20

Glycerol is converted to _________ ______, which is oxidized via glycolysis

Back 20

D-Glyceraldehyde 3-phosphate

Front 21

Ketone bodies are formed in

A- adipocytes
B- All cells
C- hepatocytes
D- myocytes

Back 21

C

Front 22

ketone bodies are formed in the liver because gluconeogenesis depletes ____ intermediates, thus diverting _____ away from oxidation and toward the production of ketone bodies

Back 22

TCA
acetyl-CoA

Front 23

what happens to ketone bodies AFTER they are synthesized?

A- they are exported to tissues
B- They are oxidized in the mitochondria of the liver
C- They are converted to acetyl-CoA and exported to tissues
D- They are used in gluconeogenesis

Back 23

A

Front 24

after they are synthesized in the liver, ketone bodies are exported to tissues such as the ____ and ______, where they are converted to _____, which enters the ______ to be oxidized as fuel.

Back 24

brain and liver
Acetyl-CoA
TCA

Front 25

Both w-oxidation and beta-oxidation of fatty acids in animals

A- require water
B- take place in mitochondria
C- generate NADH
D- use fatty acyl-CoA esters as substrates

Back 25

C

Front 26

one cycle of w-oxidation generates ____ molecules of NADH, while one cycle of beta-oxidation generates _____ molecule each of NADH and FADH2

Back 26

2
1

Front 27

Which of the following is TRUE about ketone bodies?

A- they raise the pH of the blood
B- They are the brain's preferred energy source
C- They cannot be used as fuel
D- They are water-soluble

Back 27

D

Front 28

Ketone bodies are soluble in blood and urine, potentially causing the conditions ____ and ______

Back 28

acidosis and ketosis.

Front 29

what are the 3 ketone bodies?

Back 29

acetone
acetoacetate
D-Beta-hydroxybutyrate

Front 30

what is alpha-oxidation?

Back 30

it is an alternative path for oxidation in peroxisomes

Front 31

what is a mixed function oxidase?

Back 31

it is an enzyme that catalyzes, in which two reductants are oxidized: NADPH, and the substrate.

One oxygen atom is encorporated into the product, and the other is reduced to H2O

Front 32

what is w-oxidation?

Back 32

alternative form of oxidation in which the intial oxidation occurs at the methyl carbon (most distant carbon from carbonyl carbon)

Front 33

what is a lipoprotein?

Back 33

it is a lipid-protein aggregate that serves to carry water-insoluble lipids in the blood. The protein component alone is an apolipoprotein

Front 34

what is acidosis ?

Back 34

a metabolic conditoin in which the capactiy of the body to buffer H+ is diminished; usually accompanied by decreased blood pH

Front 35

what is serum albumin?

Back 35

a major protein of the blood plasma which carries fatty acids and contributes to the osmolarity of the plasma

Front 36

what is the carnitine shuttle?

Back 36

mechanism for moving fatty acids from the cytosol to the mitochondrial matrix as fatty esters of carnitine

Front 37

what is beta oxidation?

Back 37

oxidative degradation of fatty acids into acetyl-CoA by successive oxidations at the beta carbon?

Front 38

what is alpha oxidation

Back 38

an alternative path for the oxidation of beta-methyl fatty acids in peroxisomes