2.4)Enzymes Flashcards
what are enzymes?
biological catalysts that speed up the rate of metabolic reactions without being used up
what type of proteins are enzymes?
globular
how do enzymes work?
interact with substrate mol. to form enzyme substrate complex (ES)
what is the turnover number?
number of reactions that an enzyme can catalyse in one second
what is a difference between chemical catalysts and enzymes?
-they can work at lower temp, neutral pH + lower press
-more specific than chemical catalysts
what effects do gene mutations have on enzymes?
-alter the AA sequence of a protein
-alter the enzymes tertiary structure
-prevent enzyme from functioning
what can a deficiency in enzymes cause?
metabolic disorder
what is an active sight?
indentation or cleft on the surface of the enzyme consisting of about 6~10 AA
what structure does the active sight have?
tertiary
why is the tertiary structure of the active sight crucial?
-shape is complementary to the shape of the substrate binding to it
why are enzymes specific?
the active sight is complementary to the substrate
how to enzymes affect the activation energy ?
lowers the activation energy to get the reaction started
what is the activation energy?
minimum energy to start a reaction
what are intracellular enzymes?
-act within cells
-structure and function of cells
what are the 3 pathways that intracellular enzymes take?
-metabolic
-anabolic
-catabolic
what is the metabolic pathway?
each step catalysed by a different enzyme
what is the anabolic pathway?
large mol. synthesised from small mol.
what is the catabolic pathway?
large mol. broken down into smaller mol.
what is one product of metabolic pathways?
hydrogen peroxide
which enzyme breaks down hydrogen peroxide?
catalase
how does catalase protect the cell from damage from reactive oxygen?
breaks it down into water + oxygen
what are extracellular enzymes?
work outside the cell
what is one type of the extracellular enzymes?
-digestive enzymes secreted from the cells lining the alimentary canal in the lumen of the gut
-digest large mol. (fat,protein + starch)
-absorbed into the bloodstream
what are 2 types of digestive enzymes?
-amylase
-trypsin