Protiens Flashcards
What are the monomers of proteins?
Amino Acids
What are the three structural groups in amino acids?
Carboxyl Group- COOH
Amine group- NH4
Variable group- R
What is a dipeptide, what reaction do they form during and what bonds do they form?
A dipeptide is two amino acids joined via condensation reactions and they form peptide bonds.
Name the four structures of proteins:
Primary
Secondary
Tertiary
Quaternary
What happens during the primary structure?
The primary structure is where amino acids are joined by peptide bonds via condensation reactions. It determines the specific sequence of amino acids.
What happens during the secondary structure of proteins?
Folding and coiling of these polypeptide chains to form either an alpha helix or a beta pleated sheet which are held via hydrogen bonds.
What happens during the tertiary structure?
More folding and coiling into a globular or fibrous shape. These are held by hydrogen, ionic, disulphide bonds and it creates a specific 3D structure and shape specific to its role/function.
What is the quaternary structure?
Happens when there is more than one polypeptide chain.
What are some functions of proteins?
Provides structure to cells- keratin
Enzymes
Transport oxygen- haemoglobin RBC
Help with immunity- antibodies
How many naturally occurring amino acids are there?
20
Why do different proteins have different structures?
Different order and number of amino acids in the primary structure this means different R-groups in different places.
So the hydrogen, ionic and disulphide bonds will form in different places so there would be a change in tertiary structure meaning a different 3D shape which carries out different functions.
Why do proteins become denatured?
Bonds in the tertiary structure are broken by heat or pH which changes the shape of its tertiary structure so it has a different 3D structure which means it cannot carry out its original function.
Test for proteins?
The biuret test.
