Ch. 2-3 Biochemistry

Polar covalent bonds

chemical bond where electrons are shared unequally between 2 atoms, creating one positively and one negatively charged

Polar molecule

the water overall charge is unevenly distributed

Cohesion

the hydrogen bonds hold the substance together

Adhesion

the clinging of one substance to another

Surface tension

a measure of how difficult it is to stretch or break the surface of a liquid

Thermal energy

the kinetic energy associated with the random movement of atoms or molecules

Temperature

a measure of energy that represents average kinetic energy of molecules in a body of matter

Heat

thermal energy in transfer from one body of matter to another

Specific heat

the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 degree Celsius

Heat of vaporization

the quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state

Evaporative cooling

as a liquid evaporates the surface of the liquid that remains behind cools down

Solution

a liquid that is a completely homogeneous mixture of two or more substances

Solvent

the dissolving agent of a solution

Solute

the substance that is dissolved

Aqueous solution

the solute is dissolved in water; water is the solvant

Hydration shell

the sphere of water molecules around each dissolved ion

Hydrophilic

(water loving) any substance that is attracted to water

Hydrophobic

(water fearing) any substance that repels to water

Hydrogen ion

(H+) a single proton with a charge of 1+

Hydroxide ion

(OH-) has a charge of 1-

Hydronium ion

(H₃O+)

Acid

a substance that increases the hydrogen ion concentration of a solution

Base

a substance that reduces the hydrogen ion concentration of a solution

pH scale

measures how acidic or base a substance is (0-14)

pH

pH= -log (H+)

Buffer

a substance that minimizes changes in the concentrations of H+ and OH- in a solution

Carbohydrates

-serve as a cell's fuel and building material

-the class of molecules that range from small sugar molecules (such as those dissolved in soft drinks) to large polysaccharides (such as starch)

-composed of C, H, and O

-hydrophilic

-has two types : monosaccharides and polysaccharides

-have molecular formulas that are multiples of CH2O (e.g. C60H100O50)

hydrolysis reaction

A chemical reaction that breaks apart a larger molecule by adding a molecule of water

enzymes

Proteins that speed up chemical reactions

Glycogen

An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.

Cellulose

A substance (made of sugars) that is common in the cell walls of many organisms;

polysaccharide consisting of glucose monomers that reinforces plant-cell walls

Starch

A storage polysaccharide in plants consisting entirely of glucose.

Monosaccharides

glucose, fructose, galactose

Polysaccharides

large macromolecules formed from monosaccharides; Carbohydrates that are made up of more than two monosaccharides

monomers

small unit that can join together with other small units to form polymers

dehydration reaction

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

Polymer

A long molecule consisting of many similar or identical monomers linked together.

Methyl

-CH2, Non-polar, Hydrophobic, found in R groups and lipids

Carbon

C 6

polar molecule

a molecule in which one side of the molecule is slightly negative and the opposite side is slightly positive

ionic bond

Formed when one or more electrons are transferred from one atom to another; A chemical bond resulting from the attraction between oppositely charged ions.

Covalent bond vs Ionic bond

A COVALENT BOND forms when electrons are shared between atoms.

An IONIC BOND is formed when one or more electrons are transferred from one atom to another.

Hydrocarbons

organic molecules consisting of only carbon and hydrogen

Isomers

Same atoms but different arrangement.

saturated fatty acid

A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton.

a long-chain hydrocarbon with single covalent bonds in the carbon chain; the number of hydrogen atoms attached to the carbon skeleton is maximized

unsaturated fatty acid

a fatty acid whose hydrocarbon chain contains one or more double bonds

Chitin

A structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeletons of all arthropods.

monosaturated fatty acid

A fatty acid with one double bond between carbon atoms

polysaturated fatty acids

Has many double bonds. Not packed tightly at all. Liquid at room temp. Double bond susceptible to oxidation. Ex: Vegetable Oil.

Lipids

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

gylcerol

an alcohol composed of a 3-carbon chain, which can serve as the backbone for a triglyceride

fat

A lipid consisting of three fatty acids linked to one glycerol molecule; also called a triglyceride.

trans fats

An unsaturated fat, formed artificially during hydrogenation of oils, containing one or more trans double bonds.

Protein

An organic compound that is made of one or more chains of amino acids and that is a principal component of all cells

carboxyl group

(-COOH), Polar, hydrophillic, found in all proteins

COOH

carbonyl group

C and O double bond

C=O

a chemical group consisting of a carbon atom linked by a double bond to an oxygen atom

hydroxyl group

(-OH), Polar, Hydrophillic, found in some R groups and fatty acids

amino group

(-NH2), Polar, Hydrophillic, found in all proteins

peptide bond

covalent bond formed between amino acids;

The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid

R groups

groups give different amino acids different properties

Polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

primary structure

The first level of protein structure; the specific sequence of amino acids making up a polypeptide chain.

secondary structure

Either an alpha helix or beta pleated sheet.

tertiary structure

The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.

quaternary structure

The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.

DNA

deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

RNA

A single-stranded nucleic acid that passes along genetic messages; its job is in assembling the polypeptides according to the instructions of DNA.

nucleotides

monomers of nucleic acids

N (element)

Nitrogen

Sulfhydrl

-SH, Polar, Hydrophillic, found in cysteine (protein)

Phosphate

-PO4, Polar, Hydrophillic, found in phosphorylated proteins and phospholipids