The chemical elements present in amino acids
C, H, O and N (C, H, O are the main 3 in all)
Four groups of amino acids
Nonpolar, polar, acidic, and basic
The type of reaction which occurs when amino acids join together to form polypeptides
The four levels of protein structure
Primary, secondary, tertiary, quaternary
Primary structure of a protein and chemical bond
Has a unique sequence of amino acids and is just one strand. All amino acids have the alpha carbon bonded to a hydrogen atom, carboxyl group, and amino group
Proteins are composed of (monomers)
Amino acids
Amino acids are linked together by
Peptide bonds to form chains
Secondary structure of a protein
1. å helix: a delicate coil held together by hydrogen bonding between every fourth amino acid.
2. ß pleated sheet: two or more regions of the polypeptide chain connected by hydrogen bonds between the backbones.
Type of bonding: Hydrogen
Tertiary structure of a protein
Refers to the comprehensive 3-D structure of the polypeptide chain of a protein. Hydrophobic interactions, hydrogen bonding, ionic bonding, and disulfide bridge.
Quaternary structure of a protein
Refers to the structure of a protein macromolecule formed by interactions between multiple polypeptide chains. Each polypeptide chain is referred to as a subunit. Proteins with quaternary structure may consist of more than one of the same type of protein subunit. They may also be composed of different subunits. Hemoglobin is an example of a protein with quaternary structure. Hemoglobin, found in the blood, is an iron containing protein that binds oxygen molecules. It contains four subunits: two alpha subunits and two beta subunits.
Secretion of proteins
Many of the proteins produced by a cell will be secreted to be used outside of the cell
The site of protein synthesis
Packages proteins for export
Golgi apparatus
Salivary gland cell
Secretes Amylase
Pancreatic cell
Secretes insulin
Stomach wall cell
Secretes pepsin
Pituitary gland cell
Secretes ADH
Secretes antibodies
How many different monomer units are found in proteins
20 amino acids
Conjugated protein
A complex protein, such as hemoglobin, consisting of amino acids combined with other substances
Structural protein
Part of the structure of hair, Keratin.
Part of structure of spindle fibers, Tubulin.
Hormonal (Messenger) protein
Coordination of an organism's activities, ADH
Defensive (Messenger) protein
Binds to antigens and sends signals to lymphocytes, Antibody
Contractile and Motor (Structural) proteins
Movement structure of muscles, Myosin and Actin
Carrier proteins
Transports oxygen to tissues, Hemaglobin
Enzymatic proteins
Joins together nucleotides to form DNA, DNA polymerase
Induced by the presence of lactose in the lac operon system in E.coli
Soluble or insoluble protein
Fibrous: Insoluble
Globular: Soluble
Structural or molecular recognition protein
Fibrous: Structural
Globular: Molecular recognition
Parallel strands or spherical shape
Fibrous: Parallel
Globular: Spherical
The significance of polar and non-polar amino acids
Controlling the position of proteins in membranes,
Creating hydrophilic channels through membranes,
Specificity of active site in enzymes