Part 4 - Proteins Flashcards
Proteins
Complex molecules made of a chain of amino acids, order of amino acids determines the proteins shapes and its functions
Each protein will have a different order of amino acids
What are the 6 types of proteins?
Haemoglobin, antibodies, hormones, enzymes, structural, receptors
Haemoglobin
The iron containing oxygen, transport oxygen in red blood cells, gives red blood cells their red colour
Antibodies
Produced by white blood cells, protect body from harmful microbes
Hormones
Chemical messengers, e.g insulin and glucagon
Structural
Forms supporting framework inside cells and forms body structures, e.g tubulin and keratin
Receptors
Structures that hormones bind to
Enzymes
Made of protein, biological catalysts, increase the rate of a chemical reaction by lowering the activation energy, reusable, unchanged by chemical reactions, produced by all living cells, specific because they can only react with one substrate because the shape of the active site is complementary to that substrate, can be involved in degradation and synthesis reactions , eg lipase and amylase
Explain an enzyme reaction
Enzyme meets complementary substrate, substrate fits into the enzymes active site like a lock and key forming an enzyme substrate complex, products are made and released from the enzyme
Degradation enzyme reactions
Fats —lipase— fatty acids+glycerol
Starch —amylase— maltose
Protein —pepsin— peptides
Hydrogen peroxide —catalase— oxygen+water
Synthesis enzyme reaction
Glucose+phosphate —phosphorylase— starch
What factors affect enzyme activity
Temperature (humans optimum is 37)
And pH
What is optimum condition?
The point where the enzyme works at its most active and best rate
If temperature goes above its optimum, what happens?
The activity decreases
Explain an enzyme that is denatured
Definition: The enzyme active site has permanently changed shape meaning the substrate will no longer it into the active site
Cause: Very high temperature, above the optimum , pH out of the working range
