Protiens Flashcards
What is a amino acid comprised of
There is an amine group a carboxyl group and an r group (variable) that can be any number of molecules depending on the different proteins it will form
Identify the atoms that are removed in the formation of a polypeptide and what reaction is used
there is a condensation reaction that removes water to form the bond (peptide)
What is the name of the reaction that is used to seperate the the chain
hydrolysis
Describe the primary structure of a protein
chain of amino acids in a particular order that are joined together with the use of peptide bonds.
What are the two forms a secdodnary protein molecule can take?
Alpha Helix or beta pleated sheet
What chemical bonds are used in a tertiary structure
Ionic, hydrogen, peptide, disulphide bridges
Describe the quaternary strucutre
2 or more polypeptide chains that are joined together
Name any globular proteins
2 marks
Haemogoblin , hormones, myoglobin and antibodies
Name any fibrous proteins
Keratin, collagen, elastin, tropin, myosin
what is the test for proteins and how is it carried out
the test is the biuret test and it is carried out by adding sodium/potassium hydroxide to the sample. then adding a few drops of copper sulphate and then if the sample turns purple there is a protein present.
Compare the properties and functions of fibrous proteins and globular proteins in the human body
Fibrous proteins are used primarily for the structural role. They are strong, thin and are insoluble to water so that they can provide strength in the areas they are present within. Another property of some fibrous proteins is being elastic. This allows the protein to stretch when needed and then to recoil such as the elastin lining the arteries to cope with pressure. Whereas globular proteins are used for the metabolic role within the body to ensure process are carried out such as the haemoglobin with the transport of O2 and pepsin with the digestion of proteins in the stomach.
Characteristics of collagen
This is a fibrous protein that is used for structural support. It is comprised of a triple helix of firbril. The protein is used in connective tissue between bones and in the arteries to provide the strength needed to handle the high pressures of blood.
characteristics of keratin
The properties of keratin are the pure strength, toughness and impermeability to water to prevent water bound infections. Keratin is normally used in hair and nails.
characteristics of elastin
The main property of elastin is the coiling and cross-linking that allows it to be extensible and stretch to cope with any movements. Such as within the skin and in the lungs. The ability for these to be able to stretch and recoil back to the original shape is a key process
Characteristics of Haemoglobin
This has a Quaternary structure that consists of 4 polypeptide chains. There are 2 alpha globin chains and two beta globin chains. All of these tertiary structures combined form the haemoglobin molecule. Each of the 4 chains contain a prosthetic group that contains an iron ion with either 2+ or 3+ charge. this is used to bond with oxygen to then carry it around the body.This makes the molecule conjugated.
