Proteins Flashcards
(34 cards)
How many naturally occurring amino acids are there
20
Draw an amino acid
Draw on white board and check note
What do all amino acids have
NH2 and COOH
Formula of glycine
H
Formula for alanine
CH3
Formula for valine
C3H7
What are the element found in amino acids
C H O N and some amino acids S
What is the primary structure of an amino acid
The number and the sequence of the amino acids in the polypeptide chain
What is a peptide bond and what typed of reaction is it
Amino group of one amino acid reacted with carboxylic COOh group of another
VIA CONDENSATION REACTION
What is the secondary structure
The regular folding of polypeptide chain held together by hydrogen bonds
What are the two types of secondary structures
Alpha helix
Beta sheet
How does the secondary structure work
Hydrogen bonds form between a carboxyl group of one amino acid and imino ( NH) group of amino acids in adjacent chains
What is the tertiary structure
Further folding of the polypeptide chain to form a precise compact and geometric shape
What bonds are included in the tertiary structure
Hydrogen bonds
Disulfide bonds
Ionic bonds
Hydrophobic and hydrophilic interaction
What is the quaternary structure
Two or more polypeptide chains
What is a globular protein
Protein with a spherical shape that is solvable in water and have metabolic roles
Haemoglobin
4 polypeptide chains - quaternary structure ( 2 alpha globin and 2 beta globin)
Conjugated protein has a prosthetic group attached to each polypeptide chain
Four prosthetic group in haemoglobin called haem groups and contain an iron ion ( fe2+)
One oxygen molecules binds to each haem group for transport
Insulin
Two polypeptide joined by disulfide links
Shape of insulin allowed it to specifically bind to receptors on cell membrane to reduce blood glucose
Hydrophilic R groups on the outside soluble in water
Allows insulin to disslove in water
Pepsin
Primary structure has few basic r groups preventing tertiary structure from being affected by low pH
Kept stable by h bonds and disulfide links
What is the fibrous protein
Very long strong insoluble protein with a structural role in organism
Collagen
3 polypeptide chains
Cross linked to provide mechanical strength
Chains are wound around each other
Chains are held by hydrogen bonds
Hight proportion of glycine
Keratin
High amounts of cysteine
Amino acid containing sulfur
Disulfide links form between the two polypeptide chains make molecules hard and strong
Elastin
Crosslinking between poly peptide chains creates a coiled arrange ment
Calcium ions
Synaptic transmission of nerve impulses
Bone structure
Cofactor in blood clotting
Muscle contraction
