S1: Amino Acids and Protein Synthesis Flashcards
Why are amino acids optically active?
The central carbon is a chiral carbon and has 4 different groups attached
Where are D- amino acids found?
In the peptidoglycan bacterial wall
What is the structure of an amino acid?
(Pic)
What type of amino acids are found in humans/nature?
L- amino acids which are optically active
What are a- amino acids
An amino acid where the central carbon bound to the amino group is also bound to the acidic carboxyl group.
What is the ‘R’ group in amino acids?
The ‘R’ group is variable and it also known as the side chain.
It is different in each type of amino acid.
At a neutral PH (isoelectric point), what do amino acids exist as?
They exist as zwitterions. When an amino acid is a zwitterion, the carboxyl group is deprotonated and positively charged, while the amine group is protonated and positively charged.
What happens to an Amino Acid when the PH is low (3/4)?
The carboxyl group gets protonated as well as the anime group already being protonated which gives the amino acid a positive charge.
What happens to an Amino Acid when the PH is high (above 9/10)
The amino group will get deprotonated (and is no longer ionised) and the carboxyl group will remain deprotonated giving the amino acid a negative charge.
How are the 20 different side chains in amino acids grouped?
Polar/apolar
Hydrophobic/hydrophilic
Where do polar and non polar amino acids exist in the cell?
Polar amino acids tend to exist in the hydrophilic regions of the cell.
Non polar amino acids tend to exist in the hydrophobic parts of the cell
What are the subdivisions of polar amino acid side chains ?
Polar acidic
Polar neutral
Polar basic
What are the subdivisions of non polar amino acid side chains?
Aliphatic (straight/branched chains)
Aromatic (ring)
These can be further broken down into being acidic or basic
How do we get essential amino acids that our body cannot make?
We consume them in our diet
What is a polypeptide?
A polypeptide is a chain of amino acids
A protein can be constructed from one or more polypeptide chain
What type of reaction form a peptide bind between the carboxyl and anime group on two different amino acids?
A condensation reaction where water is released