What is the Primary purpose of metabolism?

what is the significance of excess ketones?

They can be absorbed across the blood brain barrier and used for energy by the brain

Ketogenic amino acids cannot enter gluconeogenesis because:

They can only be converted to acetyl CoA or ketones and their carbons are lost as carbon dioxide in the Kreb's cycle

What is the primary purpose of metabolism?

To exchange energy and matter between a cell and its environment.

What process defines the cori cycle?

Transport of muscle lactic acid to the liver for conversion to glucose by glucogeogenesis

A spontaneous reaction has a - change in G...a decrease in free energy

True

Emulsification of dietary lipids in the small intestine by bile acids greatly facilitate digestion by lipases by forming micelles with greatly increased surface area..

True

Glycolysis is a fermentation Process..

True

Milk fat can be digested in the stomach by gastric lipase since this enzyme is very specific for short chain fatty acids on TAGS

True

T/F: All carbons of a fatty acid come from acetyl CoA

True

T/F: Citrate inhibits PFK and promotes F-1,6 bp of gluconeogenesis:

True

T/F: Glucokinase and glycogen synthase in liver cells are induced by insulin:

True

T/F: Liver cells do not respond to insulin for the transport of glucose into liver cells

True

T/F: The formation of UDP-glucose is an energy requiring reaction:

True

dietary fats with long chain fatty acids have limited digestion in the stomach so digestion primarily occurs in the small intestine by pancreatic lipases

True

T/F: Amino Acids from protein catabolism enter gluconeogenesis as pyruvate or as TCA intermediates:

True.

Precursor of skin melanin:

Tyrosine

TAGS produced endogenously in the liver are transported in the bloodstream as

VLDL

Under what conditions will fatty acid oxidation result in the formation of ketones?

When excess fatty acid oxidation and diminished oaa in the kreb's cycle

Do oxidation reduction reactions occur during glycolysis?

Yes.

In the intestinal enterocytes, TAGS are reformed from fatty acids larger than 12 carbons..

Yes. True.

Are Catabolic reactions spontaneous?

Yes.True.

Carrier molecule for long chain fatty acids through the mitochondrial membrane

carnitine

Glucagon promotes gluconeogenesis by:

causing the reduction in f-2,6 bp

What are bile acids chemically similar to?

cholesterol

Lipoproteins that are exocytosed from the intestinal enterocytes into the lymph system, and have a specific function to transport dietary lipids

chylomicrons

A non protein component of an enzyme that is an organic compound

coenzyme

Required for pancreatic lipase to function by facilitating binding of lipase to micelles:

colipase

Entropy

dissipated potential

What leads to acidosis?

excess ketones in the bloodstream

How many coenzymes are required for the pyruvate dehydrogenase complex?

five

How many different B vitamins are required for the synthesis of the coenzymes of the pyruvate dehydrogenase complex?

four

What does glucose released from glycogen by glycogenolysis enter glycolysis as?

glucose -6-phosphate

In brain and muscle tissue, ammonia generated from amino acid catabolism is transported in the blood to the liver and kidneys as:

glutamine.

Glycogenesis in the liver:

helps maintain blood glucose levels

common type of reaction of all digestive enzymes

hydrolysis

Where does the urea cycle occur?

in the periportal cells of the liver

Why is retrograded starch harder to digest by amylases

it has a lower glycemic index

The fate of the amino group removed in the deamination of amino acids is:

it is removed as ammonia and enters the urea cycle

Glucokinase ensures a glucose gradient for glucose transport into liver cells by...

phosphorylation of glucose

Which glycolytic enzyme is genetically regulated in response to glucose levels in the liver?

pyruvate kinase

The symport of amino acids into cells that utilizes a sodium gradient to facilitate the transport of amino acids or glucose is...

secondary active transport

What is the main site of amino acid catabolism?

the Liver

What lipidss would be good emulsifiers?

the amphipathic lipids--bile acids, phospholipids, fatty acids

Each molecule of NADH oxidized in the electron transport system generates how many molecules of ATP?

three

How many different enzymes does the pyruvate dehydrogenase complex that converts pyruvate from glycolysis to acetyl coA, have?

three

In how many stages does catabolism take place?

three

What is the function of lipoprotein lipase on the surface of muscle and adipose cells?

to hydrolyze the TAGS in chylomicrons and VLDLs

What lipids are NOT amphipathic?

triacylglycerols

Each molecule of FADH2 oxidized in the electron transport system generates how many molecules of ATP?

two

Standard free energy change for the complete oxidation of 1 mole of glucose

-686 kcal

What is the net production of NADH from glycolysis during anaerobic conditions?

0

Each cyle of beta-oxidation of fatty acids produces:

1 NADH and 1 FADH2

What is the net production of ATP from glycolysis?

2

How many acetyl CoA molecules are produced by beta-oxidation of stearic acid?

9

How many AtP would be produced per molecule of glucose if it was 100% efficient?

95

Allosteric promoter of pyruvate carboxylase:

Acetyl CoA

The area of the fatty acid synthase complex where malonyl CoA is bound for the "loading" step and subsequent cyclic addition for chain elongation is:

Acyl Carrier Protein

What amino acids through transamination or deamination can enter the Kreb's cycle to be oxidized for energy?

Alanine, glutamic acid, and leucine

Strenuous muscle activity can cause a rapid release of glucose from muscle glycogen by phosphorylase b due to?..

Allosteric control by high levels of AMP

In the nomenclature for fatty acids, the carbon adjacent to the carbonyl carbon of the carboxyl group is the:

Alpha Carbon

What does the deamination of glutamic acid result in the formation of?

Alpha-ketoglutaric acid

Associated with chylomicrons and facilitate the transport of these particles in the aqueous bloostream

Apoproteins

One of the amino groups in urea comes from ammonia and the other amine groups comes from:

Aspartic acid

Why are lipids considered to be "energy dense"?

Because they are highly reduced molecules

The conversion of phenyalanine to tyrosine requires the coenzyme:

Bipoterin

Phosphorolysis

CLEAVING a glycosidic bond in glycogen by the ADDITION of PHOSPHATE

Which carbon of a fatty acid is involved in the formation of ester bonds with glycerol in triacylglycerols?

Carbonyl carbon of the carboxyl group

The precursor of estrogen, testosterone, vitamin D, and bile acids is:

Cholesterol

Composed primarily of 80-85% cholesterol

Chylomicrons

Free Fatty acids formed by the action of the hormone-sensitive lipase in adipose cells is transported in the bloodstream as:

Complexes with serum albumin

Enzymes always present in nearly constant amounts:

Constitutive enzymes

What type of enzyme is involved in the oxidation-reduction reactions of the Kreb's cycle that produce NADH?

Dehydrogenases

F-2,6 bp regulates gluconeogenesis by allosterically inhibiting which enzyme?

F-1,6 bp

What noncarbohydrate source cannot be used for gluconeogenesis?

Fatty acids

What lipids ARE amphipathic?

Fatty acids, bile acids, phospholipids

In a reaction, the energy that becomes available to do work

Gibbes free energy (G)

What hormone converts the less active "b" form of glycogen phosphorylase to a more active "a" form as one awakens?

Glucagon

The natural antioxidant, glutathione, is produced from which two amino acids:

Glutamate and cysteine

Glycerol enters gluconeogenesis as:

Glyceraldehydes-3-phosphate

What enzyme in cholesterol synthesis is inhibited by statins?

HMG CoA reductase

The specific reaction catalyzed by lipase enzymes:

Hydrolysis

What inhibits the hormone-sensitive lipase of adipose cells?

Insulin

How is glycerol catabolized?

It is converted to glyceraldehyde-3-P and then enters glycolysis

What is the significance of the branched structure of glycogen?

It provides many "nonreducing ends" for cleavage of glucose molecules

Amino Acids that are not glucogenic

Leucine and Lysine

The precursor of the prostaglandin is:

Linoleic Acid

The action of pancreatic lipase results in a mixture of:

MAGS and free fatty acids

What is the cofactor in the first reaction of glycolysis catalyzed by hexokinase since cellular ATP actually exists as Mg-ATP?

Magnesium

Since ooa cannot permeate mitochondrial membranes, it must first be converted to which compound for transport?

Malate

The compound that is an allosteric activator of the enzyme that produces carbonyl phosphate in the urea cycle:

N-acetyl glutamic acid

The reduction reaction in fatty acid synthesis uses which of the following coenzymes?

NADPH

What B vitamin is necessary for the synthesis of coenzyme NAD?

Niacin

In the nomenclature for fatty acids, the methyl carbon or the carbon furthest removed from the carbonyl carbon of the carboxyl group is the:

Omega Carbon

Which glycolytic enzyme is controlled by the ATP/ADP ratio and by citrate?

PFK..phosphofructokinase

What B vitamin is necessary for the synthesis of coenzyme A?

Pantothenic Acid

A Zymogen...

Pepsinogen

What B vitamin is necessary for the synthesis of coenzyme FAD?

RiboFlavin

Dietary Lipids:

TAGS--Triacylglycerols

The conversion of serine to glycine requires the coenzyme:

Tetrahydrofolate

What is the first step of glycogenesis?

The phosphorylation of glucose