Proteins Flashcards
What are proteins made of and what is the bond that joins them
Amino acids
Peptide bond
Draw the diagram for an amino acid
H H O
| | ||
N — C — C
| | |
H R OH
What group is NH2
An amine group
What group is COOH
Carboxyl group
What does R represent in the amino acid diagram
The variable group/side chain
What happens in the primary structure of proteins
This is the amino acid chain (polypeptide)
This is determined by the DNA sequence (triplet code, codon)
What happens in the secondary structure of proteins
This is when the polypeptide initially folds
Hydrogen bonds form between the polypeptide
Could be alpha helices folding or beta pleated folding
What are the 2 main types of secondary folding
Alpha helices
Beta pleated sheet
What happens in the tertiary structure of proteins
The 3D structure involves further folding of the secondary protein which is now functional so it can do its job
What are the bonds that form in the tertiary structure
Hydrogen bonds
Ionic bonds
Disulfide bridges
What are disulfide bridges
Covalent bonds between side chains containing sulfur
They are very strong
What happens in the quaternary structure of proteins
This is when multiple polypeptides join
For example haemoglobin is made from 4 polypeptide chains
What are the 2 types of quaternary structure proteins
Globular proteins
Fibrous proteins
Structure of globular proteins
Usually round or ball shaped
Function of globular proteins
Usually have metabolic functions eg may be either enzymes or antibodies
