Cell Metabolism (Herlihy Chapter 4)

Flashcards covering the vocabulary of cell metabolism, including anabolism, catabolism, nutrient classification, energy production pathways, and protein synthesis.

Metabolism

A series of chemical reactions necessary for the use of raw materials within a cell.

Anabolism

Chemical reactions that build larger, more complex substances from simpler ones, requiring energy.

Catabolism

Chemical reactions that break down larger substances into simpler substances, releasing energy that is converted into ATP.

Monosaccharides

Single sugar compounds known as simple sugars, containing 3-6 carbons; examples include glucose, fructose, and galactose.

Disaccharides

Double sugars made when two monosaccharides are joined together, such as sucrose, maltose, and lactose.

Polysaccharides

Many glucose molecules linked together to form complex carbohydrates or starches.

Glycogen

Known as animal starch, it is used to store glucose in the liver and skeletal muscles.

Cellulose

A carbohydrate found only in plants that provides fiber and bulk (roughage) to improve digestive function.

Glucose

The most important energy source for the body, which can be burned as fuel, stored as glycogen, or stored as fat.

Anaerobic metabolism

The breakdown of glucose in the absence of oxygen, occurring in the cytoplasm and producing a small amount of ATP and lactic acid.

Aerobic metabolism

The breakdown of glucose in the presence of oxygen through the Krebs cycle and mitochondrial enzymes, producing carbon dioxide, water, and large amounts of ATP.

Glycolysis

The process occurring in the cytoplasm where glucose is broken down into pyruvic acid.

Gluconeogenesis

The making of glucose from non-glucose sources, especially protein.

Triglycerides

Lipids composed of three long chains of fatty acids attached to one small glycerol molecule.

Phospholipids

Organic compounds that form an important part of the cell membrane.

Cholesterol

A steroid found in all cell membranes necessary for the synthesis of vitamin D and sex hormones.

Essential amino acids

Amino acids that cannot be synthesized by the body and must be obtained through dietary intake.

Nonessential amino acids

Amino acids that can be synthesized by the body if they are not provided by the diet.

Peptide bond

A bond formed when the amine group ($NH_2$) of one amino acid binds with the acid group ($COOH$) of another.

Deoxyribonucleic acid (DNA)

A double-stranded nucleic acid that codes and stores the exact pattern of amino acid assembly for protein structure.

Nucleotides

The smaller units that compose DNA, consisting of a sugar, a phosphate group, and a base.

Urea

A nitrogen-containing waste product converted from nitrogen by the liver and excreted by the kidneys in urine.

Ammonia ($NH_3$)

A toxic substance produced during protein breakdown that is normally converted to urea by the liver.

Blood Urea Nitrogen (BUN)

A lab test that measures the amount of urea in the blood; abnormal levels may indicate liver or kidney dysfunction.

Hepatic encephalopathy

The toxic effects of ammonia on the brain, often observed in patients with liver failure.