1.6 - Proteins Flashcards
What are amino acids
The basic monomers of which combine to form a polymer, known as a polypeptide
How many naturally occurring amino acids are there?
20
How do the 20 naturally occurring acids differ?
By the R-Group
How do peptide bonds form?
Via the elimination of water in a condensation reaction
The water is made by combining an -OH from a carboxyl group of one amino acid with a -H atom of another amino acid.
The peptide bond is then formed between the nitrogen atom of one amino group and the carbon atom of one carboxyl group.
What is the primary structure of a protein?
The sequence of amino acids in a polypeptide
What determines the amino acid sequence within a polypeptide
DNA
What is the secondary structure of a protein?
The twisting of the polypeptide into either an Alpha helix or Beta pleated sheet
How does the polypeptide twist?
Because it contains a positive Hydrogen atom and a negative Oxygen atom, hydrogen bonds form which in turn twists the polypeptide into 2 shapes.
What is the tertiary structure of a protein?
Bonds twist and fold an alpha helices even further, giving complex 3D shapes.
What are the bonds involved within the tertiary structure of a protein?
- Disulfide bridges - Strong
- Ionic bonds - formed from carboxyl groups and amino groups not used in peptide bonding
- Hydrogen bonds - numerous, but weak
Why is the tertiary structure of a protein important?
It makes each protein distinctive and allows it to recognise, and be recognised by other molecules.
What is the quarternary structure of a protein?
The combination of different polypeptide chains and associated non-protein groups into large complex protein molecules
