Ch 8

Cortisol

A catabolic hormone made in the adrenal cortex of the adrenal glands, which are located on top of the kidneys. It promotes protein catabolism and stimulates the liver to increase its use of amino acids for gluconeogenesis. (249)

Cori cycle

A pathway in which the liver cells remove the lactate from the blood stream and recycle it into glucose. (232)

(aerobic metabolism)

ATP production that occurs in the presence of oxygen. During aerobic metabolism, adequate oxygen is present allowing mitochondria to make lots of ATP. (231)

nonalcoholic fatty liver

Abnormal accumulation of fat in the liver that is not caused by alcohol consumption. (252)

ATP yields

Alanine-14, Palmitic acid-106, and Glucose-30-32. (244)

Alcohol dehydrogenase pathway

Alcohol is metabolized to acetaldehyde by alcohol dehydrogenase. The acetate can be converted to acetyl CoA and metabolized via the citric acid cycle to yield ATP or it may be used to synthesize fatty acids or ketone bodies.

Lipoprotein lipase

An enzyme that cleaves apart a triglyceride molecule leaving 3 fatty acids and a glycerol backbone. It also hydrolyzes the triglycerides within very low density lipoproteins and chylomicrons so that the fatty acids and glycerol can be taken up by body cells and used for energy or stored as triglycerides. (246)

phosphorylation

Anabolic reaction that results in the attachment of a P group to ADP. (230)

Coenzymes

Group of organic compounds that often have B vitamins in their chemical structures. (229)

Binge drinking

Having 4 or more drinks for females and 5 or more for males per 2-hour occasion. (258)

adenosine triphosphate

High energy phosphate compound. (230)

ketogenic diet

High-fat, low-carbohydrate diet. (241)

acetaldehyde

Highly toxic substance formed during the first step of the alcohol dehydrogenase pathway. (255)

Insulin, Epinephrine, Thyroid hormone, glucagon, and cortisol.

Hormones that regulate human metabolism.

Energy metabolism

Involves the chemical pathways that enable the human body to obtain and use energy from macro nutrients and alcohol. (229)

Thyroid hormone

Is located at the base of the throat. It synthesizes and secretes two hormones that are collectively referred to as thyroid hormones. It helps the body to adapt to different situations by increasing or decreasing the rate of metabolism. This means that it can have catabolic or anabolic actions. It increases the rate of glucose catabolism, lipolysis, and protein synthesis. (249)

ketogenesis

Ketone body formation. Acetyl CoA production from beta oxidation outpaces pyruvate production from glycolysis. (241)

electron transport chain

Linked series of enzymes that synthesize water and ATP during aerobic energy metabolism. (234)

(anaerobic metabolism)

Metabolic pathways that do not require oxygen. During anaerobic conditions each molecule of pyruvate converts to lactic acid. (231)

adenosine diphosphate (ADP)

Molecule that forms when ATP loses its terminal phosphate group. (230)

carnitine

Molecule that helps fatty acids pass through the outer and inner mitochondrial membranes. (239)

The availability of carbon atoms in fatty acids increases the potential to form more

NADH, FADH2, and acetyl CoA. (241)

nicotinamide adenine dinucleotide (NAD+)

Niacin-containing coenzyme. (229)

acetyl coenzyme A

Two carbon molecule formed from pyruvate. (232)

The complete catabolism of one glucose molecule yields approximately 30 to 32 molecules of ATP.

(235)

The human body stores more energy in fat cells than in glycogen stores.

(238)

As acetyl CoA molecules are added to the hydrocarbon chain of the fatty acid, the fatty acid is able to elongate, and store energy.

(246)

Key hormones that direct or regulate metabolic activities are insulin, glucagon, cortisol, epinephrine, and thyroid hormone. Actions of each metabolic hormone depend on the body's metabolic state, which can be categorized as either absorptive or post absorptive.

(248)

standard drink

Approximately 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of liquor. Contains 13-14 grams of alcohol. A healthy liver can metabolize up to 15 g of alcohol per hour. In the US 0.08% is the legal limit. (254)

Acetyl CoA, NADH, and FADH2

Are products of the beta-oxidation of fatty acids.

alcohol dehydrogenase pathway

Catabolic pathway that metabolizes alcohol in the liver. (255)

beta-oxidation

Chemical pathway that is involved in the catabolism of an activated fatty acid. During beta oxidation fatty acid molecules are separated into two carbon segments that are converted to acetyl CoA. (239)

citric acid cycle

Complex series of chemical reactions that are involved in energy metabolism. The most important products it produces are coenzymes. They convert the two carbon acetyl CoA molecules into CO2 and H2O. (233)

Cytochrome c

Component of the electron transport chain. (235)

lactic acid

Compound formed from pyruvate during anaerobic metabolism. (232)

cirrhosis of the liver

Condition characterized by the accumulation of scar tissue in the liver, which permanently damages the organ. (257)

ketoacidosis

Condition that occurs when excess acetoacetate and beta hydroxybutyrate in the bloodstream lower the bloods pH. (242)

hormone sensitive lipase (HSL)

Enzyme in fat cells that removes the three fatty acids from a triglyceride. (239)

gastric alcohol dehydrogenase

Enzyme that detoxifies some alcohol while it is in the stomach. The alcohol dehydrogenase pathway metabolizes alcohol when a person drinks low to moderate amounts of alcohol. It is a catabolic pathway that occurs in the liver. (254)

aldehyde dehydrogenase

Enzyme that helps convert acetaldehyde to acetate, a less toxic substance. (255)

glycolysis

First phase of glucose catabolism. Glycolysis means glucose breakdown. (231)

oxaloacetate

Four carbon molecule that is an important intermediate of the citric acid cycle. It is produced during glucose metabolism. (233)

Insulin resistance

Occurs in muscle cells and adipocytes because insulin receptors no longer function properly. Obesity is highly associated with insulin resistance, a condition that can lead to type 2 diabetes. (252)

Mitochondria

Organelles that synthesize most of the ATP that cells need to function. (230)

glycogenolysis

Pathway that breaks down glycogen into glucose molecules. (235)

glycogenesis

Pathway that enables certain cells to store glucose as glycogen in the liver and muscle cells. (247)

blood alcohol concentration (BAC)

Percentage that reflects the concentration of alcohol in the bloodstream. (255)

Catabolism

Refers to metabolic pathways that break down larger molecules into smaller ones. Examples of catabolic reactions include the breakdown of glucose, fatty acid, and amino acid molecules to form carbon dioxide and water. Catabolic reactions are considered "downhill" because they result in the release of more energy than is used to initiate the reactions. Heat is part of the energy that is released. It helps the body maintain its normal temperature. Cells use the remaining energy to power chemical reactions. (229)

Anabolism

Refers to metabolic pathways that build larger molecules from smaller ones. (229)

flavin adenine dinucleotide (FAD)

Riboflavin containing coenzyme. (229)

microsomal ethanol-oxidizing system (MEOS)

Secondary pathway for processing alcohol in the liver. (255)

ethanol

Simple two carbon molecule that is more commonly called alcohol. (254)

chemical pathways

Specific chemical reactions that occur in sequences. (228)

Epinephrine

Stimulates increased fatty acids and glycerol in the blood, decreased glycogenesis, and increased glycogenolysis. (249)

lipogenesis

Synthesis of fatty acids. (247)

Gluconeogenesis

Synthesis of glucose from non-carbohydrate precursors. When the body is in need of glucose it can synthesize glucose from noncarbohydrate precursors. gluco=glucose, neo=new, and genesis=formation. (237)

The first priorities for amino acids derived from protein

Synthesize enzymes, synthesize hormones, and create structural molecules. (244)

Energy

The capacity to perform work. (228)

Insulin

The hormone that activates receptors on cell membranes of adipocytes and muscle cells and signals glucose transport proteins. It is secreted in response to a rise in blood glucose level-absorptive state. (248)

pyruvate

Three carbon molecule that results from the breakdown of glucose during glycolysis. Pyruvate is converted to a two carbon compound in the mitochondria when oxygen is present. (231)

Protein consumed in excess of body needs will be stored as amino acids in skeletal muscle.

True

Catabolic Hormones

glucagon, epinephrine, cortisol