PROTEINS Polymers (long chains) of AMINO ACIDS arranged in specific sequence linked by PEPTIDE BONDS range in length from a few to 1000+

AMINO ACIDS building blocks of proteins there are 20 common amino acids structure of an amino acid: elements included in a protein: -carbon -hydrogen -oxygen -nitrogen -sulfur (usually)

Amino acids are linked together through DEHYDRATION SYNTHESIS to form PEPTIDE BONDS

PROTEIN STRUCTURE a protein’s function depends on its specific 3-D shape

Protein Shape: determined by environmental conditions DENATURATION: protein loses its natural shape, and therefore loses its function! This can be caused by: extreme heat pH changes

HEAT

Functions of Proteins structural support (e.g. hair, nails) signaling (e.g. hormones)

Functions of Proteins • movement (contraction of muscles) transporting oxygen in the blood

Functions of Proteins • defense (antibodies of immune system) catalysis of reactions (ENZYMES)

PROTEINS WORKING AS ENZYMES are proteins control the speed of reactions (often they increase the speed of reactions)

• are not changed or “used up” by a reaction; can be used over and over

each enzyme is specific to a SUBSTRATE SUBSTRATE = the substance the enzyme acts on   Substrate ==> enzyme-sub.==> product + complex + enzyme enzyme

ACTIVE SITE = region of an enzyme which binds to the substrate is usually a pocket or groove on surface compatible “fit” between shape of enzyme’s active site and shape of substrate

Factors Affecting Enzyme Activity Temperature: as temp increases, reaction rate increases BUT, if temp gets too high, enzyme denatures and loses its shape and function optimal range for human enzymes: 35-40°C

pH: -optimal range for most enzymes: pH 6-8 *some enzymes operate best at extremes of pH (e.g. digestive enzyme pepsin, found in the acidic environment of the stomach, works best at pH 2)

Nucleic Acids nucleic acids store and transmit hereditary information Two types of nucleic acids: DNA RNA

Structure of Nucleic Acids polymers made up of monomers called NUCLEOTIDES Elements present: -carbon -hydrogen -oxygen -nitrogen -phosphorus

each nucleotide consists of: 1. a simple sugar -deoxyribose in DNA -ribose in RNA   2.   phosphate group 3.   a base (e.g. in DNA, the bases are A, G, C, and T)

nucleotides are joined together in DEHYDRATION SYNTHESIS results in a “backbone” with a repeating pattern of sugar-phosphate-sugar-phosphate...

1. DNA = Deoxyribonucleic acid forms the genetic code - the instructions for the proteins (amino acid sequences) of an organisms’ proteins is copied and passed from one generation of cells to another

2. RNA = Ribonucleic acid functions in the actual synthesis of proteins coded for by DNA