A&P Chapter 2: four major organic molecules

starch

(polysaccharide) energy storage molecule for plants; can be broken down and used as energy when ingested by humans

cellulose

(polysaccharide) important structural component of plant cell walls; not digestible by humans; provides bulk for feces

amino acids

building blocks of protiens; has an amine group, a carboxyl group, a hydrogen atom, and a side chain; characteristics determine three dimensional shape of the protein, the shape determines the function

glycerol

a 3-carbon molecule with a hydroxyl group attached to each carbon atom

polysaccharides

a long chain of monosaccharides; can be straight or branched

glycogen

a multi branched polysaccharide composed of many glucose molecules; (animal starch); main storage form of glucose in humans; stored in the cells of the liver and skeletal muscles

enzyme

a protein catalyst that increases the rate at which a chemical reaction proceeds

fatty acid

a straight chain of carbon atoms with a carboxyl group attached at one end

hydrophilic

attracted to water

denaturation

change in the shape of a protein caused by the breaking of hydrogen bonds; could be caused by high temperature changes or changes in the pH of body fluids

disaccharides

composed of two monosaccharides bound together through a dehydration reaction

triglycerides

constitutes for 95% of the fats in the human body; consists of two types of building blocks, one glycerol and three fatty acids

saturated fats

contains a single covalent bond between carbon atoms; contributes to cardiovascular disease; beef, pork,whole milk, cheese, butter, eggs, coconut oil, and palm oil

peptide bonds

covalent bonds formed between amino acid molecules during protein synthesis

primary structure

describes the unique order in which amino acids are linked together by peptide bonds to form a protein

protease

enzyme that breaks down proteins

lipase

enzyme that catalyzes the breakdown of lipids

monounsaturated fats

has one double covalent bond between carbon atoms; olive and peanut oils

unsaturated fats

has one or more double covalent bonds between carbon atoms; liquid at room temperature

polyunsaturated fats

has two or more double covalent bonds between carbon atoms; safflower, sunflower, corn, and fish oils

cholesterol

important steroid molecule; other steroid molecules are synthesize from it; important component of the plasma membrane for cells; a certain amount is vital for normal function, but to much can lead to cardiovascular disease

steroids

large family of lipids; composed of carbon atoms bound together in four ringlike structures; differs in chemical structure from other lipid molecules but has similar solubility characteristics; cholesterol, bile salts, estrogen, progesterone, and testosterone

nucleic acids

large molecules composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus

fats

major type of lipid; broken down in cells to release energy when ingested; if need is exceeded it is stored in the body for later use; provides protection by surrounding and padding organs; acts as an insulator to prevent heat loss

polypeptide

many amino acids bound together with peptide bonds

proteins

organic macromolecules that contain carbon, hydrogen, oxygen, and nitrogen bound by covalent bonds; most also contain sulfur and maybe small amounts of phosphorus, iron, and iodine; have large molecular mass; regulates body processes, acts as a transport system, provides protection, helps muscles contract, provides structure and energy; polypeptides

carbohydrate

organic molecule composed primarily of carbon, hydrogen, and oxygen atoms; can be broken down to provide the energy necessary for life; provides bulk in feces; maintains the normal function and health of the digestive tract

lipids

organic molecules that are made of a lower ratio of oxygen to carbon than carbohydrates; contains small amounts of other elements (phosphorus and nitrogen); relatively insoluble in water

active site

portion of an enzyme in which reactants are brought into close proximity, which plays a role in reducing activation energy of the reaction

secondary structure

refers to the folding or bending of the polypeptide chain; common shapes are pleated sheets and helices

quaternary structure

refers to the structure of a protein macromolecule formed by interaction between multiple polypeptide chains; made up of subunits (individual proteins)

tertiary structure

refers to the three dimensional structure of the polypeptide chain driven by the interactions within the protein and with the immediate environment

hydrophobic

repelled by water

phospholipids

similar to triglycerides, except one of the fatty acids bound to the glycerol is replaced by a phosphate containing region; polar and hydrophilic at the end of the molecule to which the phosphate is bound, nonpolar and hydrophobic at the other end

monosaccharides

simple building blocks of carbohydrates (sugar); commonly contain 3,4,5, or 6 carbons

deoxyribonucleic acid (DNA)

the genetic material of cells; copies are transferred from one generation of cells to the next ; contains the information that determines the shape of proteins; helix shape

saturation

the number or hydrogen atoms in the carbon chain of fatty acids

tripeptide

three amino acids bound together with peptide bonds

dipeptide

two amino acids bound together with peptide bonds

trans fats

unsaturated fats chemically altered by the addition of hydrogen; process makes fats more saturated; bigger contributor to cardiovascular disease that saturated fats