Proteins Flashcards
What are the structural uses of proteins?
Collagen and Keratin
Collagen is found in connective tissue, while Keratin is present in nails and hair.
Name three enzymes.
Amylase, Maltase, DNA ligase
These enzymes facilitate biochemical reactions.
What is the role of haemoglobin?
Transport
Haemoglobin carries oxygen in the blood.
List three hormones that are proteins.
Insulin, Glucagon, ADH
These hormones play crucial roles in metabolism and homeostasis.
What is the function of antibodies?
Immunity
Antibodies help the immune system identify and neutralize pathogens.
What elements do proteins contain?
Nitrogen, Carbon, Hydrogen, Oxygen
Many proteins also contain sulphur and occasionally phosphorus.
What are amino acids?
The basic monomer unit of proteins
They are the building blocks of proteins.
How many naturally occurring amino acids are there?
20
Plants can synthesize all 20, while animals must obtain some through diet.
What are essential amino acids?
Amino acids that humans have to obtain from their diet
Animals cannot synthesize these amino acids.
What process causes peptide bonds to form?
Polymerisation of amino acids
This involves a condensation reaction.
What is the primary structure of a protein?
Type, number, and sequence of amino acids linked by peptide bonds
This structure defines the protein’s unique characteristics.
What is secondary structure in proteins caused by?
Hydrogen bonds formed between NH and C=O bonds
This can lead to alpha helices or beta pleated sheets.
What types of bonds are involved in tertiary structure?
Disulphide bridges, ionic bonds, hydrogen bonds, Van der Waals forces
These bonds occur between R groups on the same polypeptide chain.
What characterizes quaternary structure in proteins?
Bonds between R groups on different polypeptide chains
The bonding types are similar to those in tertiary structure.
What are globular proteins?
Proteins with tertiary and sometimes quaternary structures, roughly spherical shapes
They are soluble and used for metabolic reactions.
Describe the structure of haemoglobin.
4 polypeptide chains with polar and charged R groups
It contains hydrogen bonds, ionic bonds, London forces, and alpha helices.
What are fibrous proteins?
Proteins with little or no tertiary structure, long parallel polypeptide chains
They are generally insoluble in water and serve structural functions.
What is collagen?
A fibrous protein that forms connective tissue
It has a triple alpha helix structure providing high tensile strength.
What amino acids alternate in collagen’s structure?
Glycine and two other amino acids
Glycine’s small R group allows for tight coiling.
True or False: All proteins have a quaternary structure.
False
Only some proteins, like globular proteins, have a quaternary structure.
