2.1.2K-O Biological Molecules - Proteins Flashcards
Draw and label a diagram of an amino acid.
central carbon atom with an amine group (NH2) and Carboxyl group (COOH) attatched and a Variable R group
*on flashcard
How many amino acids occur in life?
20
20 different R groups
What are the 4 different amino acids in life?
1- non polar hydrophobic
2- polar hydrophilic
3- polar hydrophilic basic (positive charged)
4 - polar hydrophilic (negative charged)
Which elements do Amino acids contain?
C, H, O, N
sometimes Sulfur
Draw a labelled diagram showing the condensation and hydrolysis of peptide bonds.
Draw a dipeptide and label the peptide bond
*on flashcard
OH from COOH
H from NH2
How does a variety of amino acids lead to a variery of dipeptides and very quickly to a v.big variety of polypeptide chains
there are 20 amino acids therefore 400 dipeptides as the order changes the molecule
- there are 20^3 tripeptides and so on giving rise to v.big variation in polypeptidesn
Define polypeptide chain
chain of 3 or more amino acids
Define protein
one or more polypeptides arranged as a macromolecule
Define dipeptide
when 2 amino acids join together
How does one end of a polypeptide chain differ from the other end?
one end is the carboxyl end (C terminal)
other end is the N terminal the amine group
Define primary structure of a protein
the number and sequence of amino acids in the polypeptide chain.
How is the primary structure of a protein held together?
the different amino acids are held by peptide bonds
Different proteins have different __________ of amino acids in their primary structure……
amino acid sequences
Define secondary structure and the 2 different types
when polypeptide chains coil into a ALPHA-helix or fold into a BETA- pleated sheet.
How is the secondary structure held in place?
By hydrogen bonds between nearby amino acids N-H groups and C=O
