Chapter 5.4 - proteins

Proteins

Protein Functions

• Structural

• storage

• transport

• cellular communications

• movement

  • and defense

Enzymes

Act as a biological catalyst to speed up chemical reactions

Regulate metabolism and can preform functions multiple times

enzymes

Storage proteins

store amino acids

transport proteins

transport of substances

Hormonal proteins

coordination of an organisms activities

receptor proteins

response of cell to stimuli

contractile and motor proteins

movement

structural proteins

support

Proteins consist of one or more

polypeptides

polypeptides are built from different combos of the same

set of 20 amino acids

What functional groups are attached to the amino acids

amino, and carboxyl

What are the R groups attached to

alpha carbon

The amino acids act as an acid and a base depending on the surroundings what happens to the H in the carboxyl group in the human body (pH 7.4)

It separates and is taken in by the amino group (to keep the surroundings a base)

What links amino acids together

peptide bonds

What is linked together as peptide bonds form

carboxyl group linked to the amino group of the next

What is the polypeptide backbone

the repetitive back bone of carboxyl and amino peptides, that the R groups are attached

Structure determines

function

Primary structure

One polypeptide chain

secondary

coils and folds from hydrogen bonds between the repeating constituents of the polypeptide backbones

Tertiary

determined by the R groups reaction with each other, within one polypeptide chain

Quaternary

multiple polypeptide chains that form one macromolecule

what are coils and folds called

alpha helix (coil), and a beta folded sheet (fold)

What type of strong covalent bond is found in tertiary

sulfide bridges

Collagen

fibrous consists of three poly peptides coild like a rope

two examples of Quaternary

collagen and hemoglobin

What is each polypeptide that is apart of Quaternary called

Subunit

Hemoglobin

globular with two alpha and two beta chins

Sickle cell disease

substitution of one amino acid, changes shape to sickle cell

the loss of a proteins native structure

denaturation

what causes denaturation

pH, salt concentration, temperature, etc

Chaperonins

Proteins that assist with the folding of other proteins

what interactions between R groups occur in tertiary structures

Hydrogen bond, ionic bonds, hydrophobic interactions, and van der Waals. Disulfide bridges maintain shapes

The tertiary structure of a protein is the

unique 3D shape of the fully folded polypeptide