Unit 3, Concept 1: Enzymes and Biochemical Reactions

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chemical reactions

the creation or breaking of bonds

activation energy

the amount of energy needed to start a chemical reaction

reactants

substrate- substances that are changed during a reaction

products

substances that are made by a chemical reaction

endothermic

absorbs energy (energy is stored as sugar, therefore endothermic)

exothermic

releases energy ie cellular respiration (energy is released when sugar is broken down, there fore exothermic reactions)

enzyme

type of protein that speeds up biochemical reactions, they are specialized molecules that bind to substrates and help to break or form bonds

active site

site on the enzyme where the reaction takes place

denaturation

enzymes active site gets deformed and loses its specific shape causing a loss of biological activity

function of enzymes

speeds up biochemical reactions

photosynthesis

6CO2 + 6H2O -> C6H12O6 + 6O2

cellular respiration

C6H12O6 + 6O2 -> 6CO2 + 6H2O

endothermic diagram

energy starts low and then gains energy for a process and ends with more energy than before

exothermic diagram

energy starts high and increases for a process then decreases as it is released

what are the 5 things that affect the rate of a chemical reaction

temperature, pH, substrate concentration, catalysts, and competitive inhibitors

temperature

higher X increases the rate of reaction as molecules move faster more collisions occur

pH

how acidic a solution is; most enzymes only work at a specific X

substrate concentration

more X means faster reaction because there are more particle collisions

catalysts

speed up reactions (like enzymes)

competitive inhibitors

slow down reactions

lock and key model

enzymes can break bonds in a substrate to form two products or make bonds between substrates to from one product

describe the lock and key model

the substrate enters the enzymes activation site and comes out as the product