UNIT 1: (1.4) Proteins Flashcards
what subunits are proteins made up of?
subunits called amino acids
How many different amino acids are there?
20
How are amino acids held together?
amino acids are held together by peptide bonds to form long polypeptide chains
what do polypeptide chains go onto form?
chains form the protein molecule
what does the structure of a protein depend on?
specific sequence of amino acids
what does the sequence of amino acids determine?
The sequence of amino acids determines the shape and function of the protein
what would happen if the order of bases is incorrect?
The protein shape will be altered and it may not be able to do its job
what is the function, shape and example of a structural protein?
- collagen makes up the body cartilage
keratin makes up hairs and nails - composed of fibres
what is an example, function and shape of an enzyme?
- examples: amylase, pepsin, lipase, phosphorylase
- involved in metabolism, break down or build-up
- globular proteins with a shape that fits snugly with the chemicals they work on
Describe an example, function, shape of a hormone.
- e.g insulin
- act as chemical messengers in the body
- insulin controls blood glucose levels
- small globular proteins
Describe the function and shape of a antibodies
- combine with foreign proteins ( antigens) and mark them to be destroyed by the body’s immune system
- globular proteins, shaped to recognise and bind with the foreign protein
Describe the function and shape of receptors
- found on the surface of particular cells which allow hormones to target these cells
- the shape of a receptor protein on a cell allows the cell to respond to a specific hormone
what are enzymes known as?
biological catalysts which are present in all living cells. They speed up chemical reactions but remain unchanged by these reactions
what effect do enzymes have on activation energy?
lower the activation energy needed for metabolic reactions to proceed in cells
name which are the catalyst, reactant and products
manganese dioxide
water + oxygen
hydrogen peroxide
manganese dioxide= catalyst
water + oxygen= products
hydrogen peroxide= reactant
what is the function of the enzyme catalase?
breakdown hydrogen peroxide which is produced in living cells into harmless oxygen and water
why does dead tissue show no reaction when boiled?
as boiling denatured the enzyme
what does denatured mean?
The change in the shape of a protein such as an enzyme that results in them no longer fitting their substrate
what are different variables?
- volume
- mass/substrate
- concentration
- temprature
what is a degradation reaction?
A breakdown reaction - when a chemical compound splits into smaller parts.
what is a synthesis reaction?
A build-up reaction - when two or more substances join together to form one product.
how are enzymes different from other catalysts?
- enzymes are made inside living cells
- all enzymes are proteins but all catalysts are not