SAS #9: Lipid Metabolism

Question 1

is a thick semi-liquid material made up of partially digested food and gastric secretions (hydrochloric acid and several enzymes).

Answer 1

Chyme

Question 2

The arrival of chyme from the stomach triggers in the small intestine, through the action of the hormone __________, the release of bile stored in the gallbladder.

Answer 2

cholecystokinin

Question 3

With the help of bile, the free fatty acids and monoacylglycerols produced from hydrolysis are combined into tiny spherical droplets called _________.

Answer 3

micelles

Question 4

A fatty acid micelle is a ________

Answer 4

micelle

Question 5

is a lipoprotein that transports triacylglycerols from intestinal cells, via the lymphatic system, to the bloodstream.

Answer 5

chylomicron

Question 6

is a triacylglycerol-storing cell.

Answer 6

adipocyte

Question 7

is tissue that contains large numbers of adipocyte cells, located primarily directly beneath the skin (subcutaneous), particularly in the abdominal region, and in areas around vital organs.

Answer 7

Adipose tissue

Question 8

storage location for the chemical energy inherent in TAGs,

Answer 8

Adipose tissue

Question 9

provides organs with protection against physical shock.

Answer 9

Adipose tissue

Question 10

is the hydrolysis of triacylglycerols stored in adipose tissue, followed by release into the bloodstream of the fatty acids and glycerol so produced.

Answer 10

Triacylglycerol mobilization

Question 11

is an intermediate in both glycolysis and gluconeogenesis. It can be converted to pyruvate, then acetyl CoA, and finally carbon dioxide, or it can be used to form glucose.

Answer 11

Dihydroxyacetone phosphate

Question 12

Oxidation of Fatty Acids:

fatty acid must be activated by boding to coenzyme A

Answer 12

Activation

Question 13

Occur at the outer mitochondrial membrane. Reactants are the fatty acid, coenzyme A, and a molecule of ATP.

Answer 13

Activation

Question 14

the activated fatty acid–CoA molecule refers to a random length fatty acid carbon chain that is covalently bonded to coenzyme A.

Answer 14

Acyl CoA

Question 15

refers to a two-carbon chain covalently bonded to coenzyme A.

Answer 15

Acetyl CoA

Question 16

Oxidation of Fatty Acids:

fatty acid must be transported into mitochondrial matrix shuttle mechanism

Answer 16

Transport

Question 17

Oxidation of Fatty Acids:

fatty acid must be repeatedly oxidized ,cycling through a series of four reactions, to produce CoA, FADH2, and NADH

Answer 17

B-oxidation

Question 18

lipids are ____ more efficient than carbohydrates for energy storage w/ equal no. of carbons

Answer 18

33%

Question 19

The first step of the citric acid cycle involves the reaction between _______ and _________.

Answer 19

oxaloacetate and acetyl CoA.

Question 20

Sufficient ________ must be present for the acetyl CoA to react with.

Answer 20

oxaloacetate

Question 21

What happens when
oxaloacetate supplies are too low for all acetyl CoA present to be processed through the citric acid cycle?

Answer 21

the excess acetyl CoA is diverted to the formation of ketone bodies

Question 22

Is one of three substances (acetoacetate, β-hydroxybutyrate, and acetone) produced from acetyl CoA when an excess of acetyl CoA from fatty acid degradation accumulates because of triacylglycerol-carbohydrate metabolic imbalances.

Answer 22

KETONE BODY

Question 23

serve as sources of energy for various tissues and are very important energy sources in heart muscle and the renal cortex.

Answer 23

KETONE BODY

Question 24

is the metabolic pathway by which ketone bodies are synthesized from acetyl CoA.

Answer 24

Ketogenesis

Question 25

The primary site for the process of ketogenesis is ____________.

Answer 25

liver mitochondria.

Question 26

The first ketone body to be produced is ______. This production occurs in Step 3 of ketogenesis.

Answer 26

acetoacetate

Question 27

steps in the process of ketogenesis: Two acetyl CoA molecules combine to produce acetoacetyl CoA, a reversal of the last step of the b-oxidation pathway via a condensation reaction.

Answer 27

First condensation

Question 28

steps in the process of ketogenesis: Acetoacetyl CoA reacts with a third acetyl CoA and water to produce 3-hydroxy-3 -methylglutaryl CoA (HMG-CoA) and CoA-SH.

Answer 28

Second condensation.

Question 29

steps in the process of ketogenesis: HMG-CoA is cleaved to acetyl CoA and acetoacetate.

Answer 29

Chain cleavage.

Question 30

steps in the process of ketogenesis: Acetoacetate is reduced to β-hydroxybutyrate. The reducing agent is NADH.

Answer 30

Hydrogenation.

Question 31

Under normal metabolic conditions (an appropriate glucose–fatty acid balance), the concentration of ketone bodies in the blood is very low about 1 mg/100 mL. Abnormal metabolic conditions, produce elevated blood ketone levels, levels 50–100 times greater than normal.

Answer 31

Ketosis

Question 32

excess accumulation of ketone bodies in blood (20 mg/100 mL) is called At a level of 70 mg/100 mL,

Answer 32

Ketonemia-

Question 33

the renal threshold is exceeded and ketone bodies are excreted in the urine,

Answer 33

Ketonuria

Question 34

the overall accumulation of ketone bodies in the blood and urine. ______ is often detectable by the smell of acetone on a person’s breath; acetone is very volatile and is excreted through the lungs.

Answer 34

Ketosis

Question 35

result of such dieting include headache, dry mouth, and sometimes acetone-smelling breath. True for fasting situation.

Answer 35

Mild ketosis

Question 36

extremely serious ketosis that can develop to persons with uncontrolled Type 1 diabetes.

Answer 36

Ketoacidosis

Question 37

is the metabolic pathway by which fatty acids are synthesized from acetyl CoA.

Answer 37

Lipogenesis

Question 38

Lipogenesis or Degradation of fatty cell cytosol

Answer 38

Lipogenesis

Question 39

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty mitochondrial matrix

Answer 39

β-oxidation pathway

Question 40

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty Enzymes are collected into a multienzyme complex called fatty acid synthase making the steps close together.

Answer 40

Lipogenesis

Question 41

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty Enzymes are not physically associated, so the reaction steps are independent.

Answer 41

β-oxidation pathway

Question 42

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty Intermediate carrier: bonded to ACP (acyl carrier protein)

Answer 42

Lipogenesis

Question 43

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty Intermediate carrier: CoA

Answer 43

β-oxidation pathway

Question 44

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty Dependent to reducing agent NADPH

Answer 44

Lipogenesis

Question 45

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty Dependent to oxidizing agents FAD and NAD+

Answer 45

β-oxidation pathway

Question 46

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty acetyl CoA is used to form malonyl ACP, which becomes the carrier of the two carbon units

Answer 46

Lipogenesis

Question 47

Lipogenesis: synthesis of fatty acids OR β-oxidation pathway: Degradation of fatty CoA derivatives are involved in all steps

Answer 47

β-oxidation pathway

Question 48

the starting material for lipogenesis

Answer 48

Acetyl CoA