Protiens Flashcards
How many common amino acids are there?
20
What 3 categories can amino acids be divided into?
non-essential, conditionally essential, essential
What are non-essential amino acids?
the body is able to produce them
What are conditionally essential amino acids?
supplemented in the diet for young and compromised animals
What are essential amino acids?
the body is unable to produce them and they need to be acquired in the diet
Describe the chemical structure of an amino acid
central carbon atom, a carboxyl group, a hydrogen atom, an amino group and a variable side chain (R) group
How can the R groups vary?
structure, size and electrical charge
What does the variety in the R groups influence?
the solubility of the amino acids in water
Can amino acids act as both acids and bases?
yes
What does a doubly charged amino acid have?
one positive and one negative charge
What are doubly charged amino acids called?
zwitterion
How many structure levels do protiens have?
4
What are the structure levels of a protien called?
primary, secondary, tertiary and quaternary
What does the primary sequence of a protein determine?
its 3D conformation and function
What can changes in the amino acid sequence cause?
severely compromise the ability of a protien to carry out it’s function
How is a peptide bond formed?
when the carboxyl group of one amino acids reacts with the amino group of another amino acid
What is produced as a byproduct in the formation of a peptide bond?
water
What are two amino acids joined by a peptide bond known as?
a dipeptide
What is a chain of amino acids known as?
oligopeptide
What is a large chain of amino acids known as?
polypeptide
What does every peptide or protein have at each end of the chain?
a free amino group at one end and a free carboxyl group at the other end
Where do disulphide bonds occur?
between the R cystine group of cystine molecules
What is eliminated in order to form disulphide bonds?
2 hydrogens and 2 electrons
what effect does the removal of hydrogen and electrons in order to form disulphide bonds have on the protein?
stabilises the proteins structure