Biochemistry Ch. 16 Final Review

How many moles of ATP and NADPH respectively, are utilized in the production of a mole of palmitate?

7, 14

Which protein comprises the coated pit of an endocytic vesicle?

Clathrin

Arrange the order of events for the internalization of LDL particles into cells:

1. LDL, made up of combination of cholesterol and apolipoprotein, binds to LDL receptors and becomes internalized as endocytotic vesicles.

2. The environment of the endosome becomes acidic, which causes the LDL to dissociate from its receptor; additionally, the endosome fuses with a lysosome.

3. Several endocytotic vesicles fuse to form an endosome.

4. The LDL particle is degraded by the lysosome.

5. LDL receptors migrate to the cell surface and cluster in clathrin-coated pits.

5-1-3-2-4

What protein does the term coated vesicle refer to?

the clathrin that forces the vesicle to invaginate

What is the trigger for the invagination of the vesicle?

occupied receptors accumulating in the coated pits

What is the term used to indicate the fatty liver condition?

Steatosis

How many moles of net ATP is produced upon oxidation of 16C fatty acid, Palmitate?

106

Which of the following are key discoveries of the experiments conducted by Brown and Goldstein?

1. Cholesterol is taken into cells through the action of a specific receptor.

2. The receptor for the LDL particle recognizes B-100 apolipoprotein.

3. The entire receptor complex, unlike hormones involved in signaling pathways, enters the cell via endocytosis.

4. Familial hypercholesterolemia patients have defective or deficient LDL receptors.

All of the listed statements are true.

What happens to your blood pH if you go into ketosis?

decreases

Which regulatory effects are results of internalized cholesterol?

It activates acyl-CoA:cholesterol acyltransferase.

It increases endogenous cholesterol synthesis.

It downregulates the production of LDL receptors.

It inhibits HMG-CoA reductase.

Statements 1, 3, and 4 are direct results of the internalization of cholesterol

Which of these processes are NOT a part of cholesterol biosynthesis?

Conversion of acetate to acetoacetate

What characteristic of bile salts help in the digestion of fats in a mammalian digestive system?

Amphipathic

What class of apolipoprotein has been associated with the development of Alzheimer's disease?

Apolipoprotein E

The families of lipoproteins are classified, based on their ________.

Density

Why is the oxidation of fatty acids called β-oxidation of fatty acids?

Oxidation of β-carbon

Myristoyl-CoA, a 14-carbon fatty acid, will be oxidized to yield how many moles of acetyl-CoA?

7

One pathway that appears to relate elevated cholesterol levels to atherosclerosis involves the oxidation of LDL. Which of the following are consequences of this process?

Though the mechanism by which this occurs is not completely understood, this oxidation includes the peroxidation of fatty acids, the hydroxylation of cholesterol, and the oxidation of amino acids.

The presence of scavenger receptors on macrophages allows unlimited cholesterol uptake, leading to its conversion to foam cells.

Oxidized LDL products induce an immune response that includes recruitment of monocytes and T lymphocytes.

All of the listed responses are consequences of this process.

Which of these is NOT a primary source for triacylglycerols in mammals?

Diet

Adipocytes

Hepatocytes

de novo biosynthesis

Hepatocytes

What is the yield of ATP per carbon oxidized during β-oxidation of fatty acids?

6.6

Which of these is NOT a class of major lipoprotein?

VLDL

LDL

Chyme

Chylomicron

Chyme

In a cell where does the oxidation of fatty acid occur?

Mitochondria

A typical 70 kg human may have reserves of ________ kJ or more in total body fat.

500,000

High level of cholesterol in blood results in the development of ________.

Atherosclerotic plaques

How much is the energy yield per gram upon complete oxidation of triacylglycerols?

37 kJ

Which of the following fatty acid is an essential fatty acid in animals?

Linoleic acid

In animal systems, fat is stored in specialized cells called ________.

Adipocytes

Which amongst these are NOT a type of ω-3 polyunsaturated fatty acid?

Docosapentaenoic acid

Eicosapentaenoic acid

Docosahexaenoic acid

Linolenic acid

Docosapentaenoic acid

What is the process by which LDL is taken up by cells?

Endocytosis

What type of lipid is most abundant in most of the organism?

Triglycerides

Which of the following statements describes cholesterol correctly?

Cholesterol is a tetracyclic hydrocarbon structure with an aliphatic chain at C-17, methyl groups at C-10 and C-13, a double bond in ring B, and an OH group in ring A

The transport of a long chain fatty acid from cytosol to outer membrane of mitochondria requires the formation of long-chain fatty acyl-CoA, achieved by enzyme ________?

Acyl-CoA synthetase

In some instances, the levels of LDL cholesterol exceed the ability of the body to maintain homeostasis, and as a result, the excess material accumulates into fatty deposits that harden into plaques. Arrange in the correct order the sequence of events that leads to this condition, known as atherosclerosis:

1. The plaques harden, blocking the flow of blood in major arteries.

2. White blood cells become engorged with fatty deposits.

3. Excess LDL cholesterol accumulates in the interior of arterial walls.

4. Macrophages are drawn to this site.

3-4-2-1

Describe a pathway whereby some of the carbon from a fatty acid with an odd-numbered carbon chain could undergo a net conversion to carbohydrate.

Propionyl-CoA, methylmalonyl-CoA, succinyl-CoA, OAA, PEP, glucose

Which of these lipid soluble vitamins acts as an antioxidant?

Cholecalciferol

Tocopherol

Phylloquinone

Retinol

Tocopherol

Retinoic acid is produced from ________ of all-trans-retinal.

Oxidation

Which of these compounds do NOT regulate the biosynthesis of cholesterol?

Farnesyl pyrophosphate

Which of these compound is NOT a part of ketone bodies?

Succinate

What level of plasma cholesterol is considered as a major risk factor for heart disease?

210 mg/100 mL