Proteins Flashcards
(19 cards)
What are proteins
Made up of monomers called amino acids
What are the chains of amino acids called
Polypeptides
What is a proteins shape determined by
Specific sequence of amino acid in the chain
Draw a generalised amino acid
H. R. O
N - c-c
H H Oh
List the names of the groups in a amino acid
Nh2 - amino group
Carboxyl group - cooh
Hydrogen atom
R group which is different in each amino acid
How does a peptide bond form
Amino group of one end reacts with carboxyl group of another with the elimination of water
When a condensation reaction of proteins happen what is formed
Dipeptide
What is a primary structure
Order of amino acids in a polypeptide chain
How is the primary structure determined
By the base sequence of one strand of the Dna molecule
Order of amino acid in polypepeptide chain
How is the a helix of secondary structure formed
Shape of polypeptide chain forms as a result of bonding between double o and co groups and h on nh group forming a coil
Alpha helix or beta pleated sheet
Structure of tertiary
A helix can be fooled and twisted to give more complex compact 3d structure
How can tertiary structure be mainTained why are these important
Hydrogen bonds Ionic bonds Disulphides Hydrophobic Give globular proteins e.g enzymes giving them their shape
What is quarternAry structure
Some polypeptides are not able to function unless they are in combination. They may combine with another polypeptide molecule or associated with non protein groups and form a large comely molecule
What does the role of proteins depend on
Their molecular shape
Structure or fibrous proteins and what does this to their function
Long thin molecules which makes them insoluble I. Water so they have a structural feature cross link which makes them strong
Examples of fibrous molecules in function
String and tough collagen is fibrous protein providing strength and toughness in the tendons
Single fibre - consists of three identical chains twisted around each other linked by hygrogen bonds making it stable tropocollagen
What is a globular protein and structure and function
Compact and folded into spherical molecule makes the soluble I water
Function - enzymes , antibodies , plasma proteins, hormones
Expanse, haemoglonin consisting of four folded polypeptide chains, inside is haem
What’s the difference between carbohydrates and lipids ?
Proteins always contains nitrogen as well as hydrogen and carbon also some proteins contain sulphur and some phosphorus
Protein tests-
SProtein tests- blue rest regent turns from blue to purple
Cooper sulphate and react with peptide binds which cause biuret purple
Biuret in colour meter using hello filter gives an estimate of relative concentration of proteins present in sample
Detect concentration of proteins present in sample use a biosensor
