Biology Key Concepts: Covalent Bonds, Mixtures, Water Properties, Organic Compounds, Enzymes, Nucleic Acids

Polar covalent bond

unequal sharing of electrons, bond that holds atoms together but gives the molecule a charge at either end

Mixture

substance composed of 2 or more elements or compounds that are mixed together

Specific heat

amount of heat needed to raise the temperature by 1 degree Celsius

Adhesion

water is attracted to other polar substances

Cohesion

water is attracted to other water molecules

Surface tension

caused by the cohesion forces of water, water molecules stick together and form a skin on the surface of the water

Solutions

type of mixture in which there is a uniform distribution of compounds

Solvent

substance that does the dissolving, substance in the greater amount

Solute

substance that is being dissolved, substance in the lesser amount

Acids

compounds that release hydrogen ions in solution

Bases

substances that release OH (hydroxide ions) in solution

pH scale

measures the strength of acids and bases

Organic compounds

carbon containing compounds; compounds found in living things

Inorganic compounds

compounds that do not contain C and are found in non-living things

Carbon atom

central atom of organic chemistry, can form 4 covalent bonds, can form chains of unlimited length

Polymerization

large compounds formed by bonding smaller molecules together

Monomer

small compounds (building blocks used to form large compounds)

Polymers

large compounds made from bonding monomers together

Carbohydrates

sugars and starches, CHO in a 1:2:1 ratio, usually end in ose and are used by the body for energy

Monosaccharides

simple sugars (glucose, fructose and galactose) contain 3 to 6 carbons

Disaccharides

double sugars (sucrose, lactose)

Polysaccharides

large carbohydrates formed by joining many simple sugars together

Glycogen

type of polysaccharide found in the muscle of animals

Starch

type of polysaccharide found in plants

Cellulose

type of polysaccharide found in the cell wall of plants

Lipids

fats, oils and waxes, store energy, building blocks are fatty acids and glycerol

Phospholipids

type of lipid that contains a phosphate group, makes up the plasma membrane

Proteins

organic compounds that contain C, H, O and N, building blocks are amino acids

Peptide bond

holds amino acids of proteins together

Amino acid

building block of a protein made of: Central C atom, carboxyl group, amino group and R group

Enzymes

type of protein that speeds up the rate of a chemical reaction

Substrates

reactants that are acted on by an enzyme

Active site

part of an enzyme where a substrate binds

Denatured enzyme

protein that has changed shape and cannot function

Nucleic acid

biomolecule made of C, H, O, N and P, building blocks are nucleotides (examples are DNA and RNA)

Parts of a nucleotide

5 carbon sugar, phosphate group and nitrogen base

Activation energy

energy needed for a reaction to occur, enzymes lower activation energy so that reactions can take place

Dehydration synthesis

2 or more monosaccharides are combined to form a larger molecule. Small molecules are put together to build a larger molecule.

Hydrolysis

large molecules, like polysaccharides, are split apart to produce monosaccharides or smaller molecules.