Proteins

Proteins

complex macromolecules that are formed from different combinations of the 20 amino acids.

Peptide bonds

The amino acids are linked by _______ _______.

Enzymatic Proteins

Selective acceleration of protein functions; speed up biochemical reactions

Structural Proteins

Support; physical stability

Storage Proteins

Storage of amino acids

Transport Proteins

Transport of other substances

Hormonal Proteins

Coordination of an organism’s activities

Insulin

a hormone secreted by the pancreas that controls the physiological process

Receptor Proteins

Response of cell to chemical stimuli

Contractile and Motor Proteins

Movement

Defensive Proteins

Protection against disease

Genetic and Regulatory Proteins

Regulates when, how, and to what extent a gene is expressed.

Primary

Amino acid monomers are joined by peptide bonds forming peptide chains.

Secondary

Polypeptide chains may form an alpha helix and beta pleated sheets. Results form hydrogen bonding.

Fibrous Proteins

Proteins that exhibit alpha helix and beta pleated sheets are called _______ _________.

Tertiary

The polypeptide chain is bent at specific sites and is folded back and forth. Polypeptides fold forming specific shapes. The folds are stabilized by bonds-hydrogen bonds and disulfide bridges. Determines the protein’s specificity.

Quaternary

Two or more polypeptides assemble to form larger protein molecules. Consists of four polypeptide chains, each one forming a heme group.

Enzymes

are special proteins and are referred to as biological catalysts.

Lipase

an enzyme whose substrate is lipid (a fat)

Sucrase

an enzyme whose substrate is sucrose (a sugar)

Denaturation

is a process which involves disruption of protein structure.

Optimum Temperature

the temperature at which the enzyme reaches its full function, is between 30-40^oC

pH

the acidity or alkalinity of a substance is called ______.

Chaperone proteins or chaperonins

assist in the folding of proteins.

Prions

These are misfolded proteins in brain cells that are linked in Alzheimer’s disease.

Nucleic acids

are formed from four kinds of nucleotide monomers linked together in long chains.

Nucleotides

are the monomers of nucleic acids.

DNA replication

DNA is reproduced precisely by _______ _______.

Transcription

DNA sequences are copied into RNA by ______

Translation

RNA is translated into proteins

Genome

______ is the sum total of all the information encoded by its gene

Lipids

______ are hydrophobic (insoluble to water) molecules that allows it to serve as a barrier in biological molecules.

Fats, phospholipids, and steroids

The most important lipids.

Fats

constructed from two types of smaller molecules; glycerol and fatty acids.

Fatty Acids

consist of long nonpolar hydrocarbons

Glycerol

is a small molecule with 3 hydroxyl ions and is an alcohol.

waxes

Plant leaves are coated with lipids called _____

triglycerides, phospholipids, and steroids

3 types of lipids that are important to cells

Saturated and Unsaturated fatty acids

Two types of Triglycerides

Saturated fatty acids

fats; solid at room temperature. Have hydrocarbon chains with no double bonds (single bond). Most animal fats

Unsaturated Fatty Acids

oils’ liquid at room temperature. Contain double bonds in their hydrocarbon chains. Plant fats and fish fats

Triglycerides

Most common; stored in fat cells of the body. Saturated and Unsaturated fatty acids; trans fat

Phospholipids

lipids combine with other substances; Lecithin

Steroids

Provides a starting point for other necessary lipids such as vitamin D and the hormones estrogen and testosterone.