3.6 Flashcards
Monomer of protein?
Amino acid
Elements proteins contain?
C H O N
How many in total and essential and non essential amino acids?
Total - 20
Essential- 9
Non essential - 5
What do proteins consist of?
One or more polypeptides (which are made of amino acids)
Synthesis of peptides?
Amino acids join when the amine and carboxylic groups react. Hydroxyl in carboxyluc group and hydrogen in amine group. Forms a peptide bond. Water is produced - condensation reaction
How can the synthesis of peptides be catalysed?
Peptidyl transferase present in ribosomes
Levels of protein structure?
Primary
Secondary
Tertiary
Quaternary
Explain primary structure
Sequence which the amino acids are joined, directed by info in DNA. This will influence the final shape and function. Only bonds involved are peptide bonds
Explain secondary structure
Oxygen hydrogen and nitrogen atoms of amino acids interact.
Alpha helix- hydrogen bonds (coil shape)
Beta pleated sheet- hydrogen bonds (pleated shape)
Explain tertiary structure
Folding of protein into final shape. R groups interact.
Interactions that occur between r groups:
Hydrogen bonds
Ionic bonds
Hydroph and hydrophil interactions
Disulphides bonds
Explain quaternary structure
Two or more protein subunits combine. Interactions the same as in tertiary structure but between diff proteins rather than within one molecule.
Test to identify proteins?
Biuret test
Sample mixed w biuret sol
Left to stand for 5 mins
(Blue to purple)