chapter 4 - enzymes Flashcards
are enzymes globular or fibrous
globular
what are enzymes
biological catalysts
what is the lock and key hypothesis
the active site ( tertiary structure ) is fit with a specific substrate forming enzyme-substrate complex . substrates react to form enzyme-product complex
what is the induced fit hypothesis
initial interaction between enzyme and substrate changes tertiary structure of active site that strengthen binding which weakens bonds on substrate and lowers activation energy
what does amylase do
breaks down starch to maltose in saliva and pancreatic juice in small intestine
what does maltase do
breaks maltose down to glucose in small intestine
what does trypsin do
digests proteins into smaller peptides
factors affecting enzyme activity
temperature
pH
substrate concentration
enzyme concentration
what are inhibitors
molecules that prevent enzymes from carrying out their normal function
what is competitive inhibitor
a molecules with similar shape to substrate of an enzyme so fits in its active site preventing substrate from entering active site
what in non-competitive inhibitor
binds to allosteric site of enzyme causing tertiary shape of enzyme and active site to change therefore active site is no longer complementary to substrate so cannot carry out its function
what is end-product inhibition
when the product formed acts as an inhibitor for the enzyme used to produce it as negative feedback to prevent excess products
what are cofactors and coenzymes
non-proten components to help enzyme function. Co enzymes are organic molecule of cofactor
what are examples of cofactors
chloride ion used in amylase to form active site to breakdown starch
zinc
calcium
iron
what vitamins form coenzymes
vitamin b3 to synthesise coenzyme NAD
vitamin B5 to synthesise coenzyme A for breakdown of carbohydrates and fatty acids in respiration
