Amino Acids Flashcards
This is responsible for the properties of amino acids and is often the differentiating factor.
Side chains
How many amino acids are there?
20
What are the 4 categories of amino acids?
Polar, non-polar, and charged (at physiological pH)
What are the 2 ways in which one letter abbreviations can be helpful?
To identify mutations and sequence alignment
This is the pH at which the group is 50% ionised.
pKa
This is the pH at which net charge on an amino acid/protein is zero
pI/isoelectric point
How are ionisable side chains classified?
Through their pKa
This is the addition of a chemical group to an amino acid residue after translation has occurred.
Post translational modification
What does PTM do?
Modifies the function of a protein; like, in a way that will switch it on/off, direct cellular location, targets for degradation
This is the bond formed between cysteine molecules.
Disulfide bond
This is often used to control enzyme activity (turn it on/off using chemical). Often characterised by having a phosphate group added to an enzyme.
Phosphorylation
This is an amino acid modification used to prevent connective tissues and scurvy.
Hydroxylation
This type of amino acid modification often involves proline and lysine.
Hydroxylation
This is needed for blood clotting, often involves glutamate
Carboxylation
This is the process of adding sugar groups to biomolecules.
Glycosylation
What are the 3 main properties of peptide bonds?
They are planar/flat, trans (a-carbons go on opposite sides), has a dipole
How are peptide bonds formed?
Dehydration reaction between C-terminal (of one amino acid) and N-terminal of another amino acid
This is a short stretch of amino acids joined together by peptide bonds.
Peptide
This is a longer chain of amino acids joined together with a defined biological function.
Protein
This is formed when amino acids are covalently bonded together in a peptide or a protein.
Amino acid residues
Where are the side chains attached?
Protein main chain
What are proteins polymers of?
Amino acids
What are the main techniques used to determine protein structure?
crystallography, spectroscopy and cryo electron microscope
