ENZYMES Protein catalysts necessary to carry out metabolic reactions in living organisms

Enzymes are necessary to carry out metabolism in our bodies… Release energy from glucose Break down proteins, starches, fats… Build new cells; repair damaged cells Replicate DNA Control cell division Destroy foreign substances in our cells Carry out protein synthesis

ENZYMES Proteins Biological catalysts Speed up rate of metabolic reactions Specific in their function Not used up

TERMS TO KNOW CATALYST Substance that speeds up reactions SUBSTRATE substance that enzyme works on ACTIVE SITE where reaction takes place b/w enzyme & substrate ACTIVATION ENERGY energy needed to start a rxn LOCK & KEY model used to describe how an enzyme works… shows enzyme specificity

How Enzymes Work Lower amount of activation energy needed to start reactions Sometimes need a cofactor (Cu, Zn, Fe) or Coenzyme (A, B-12, C, D; vitamins) to work properly; Can be altered by heat, radiation, electricity, pH, chemicals (changes the shape of the enzyme… enzyme said to be DENATURED) Keep reactions at normal Body temperature!

ENZYME SUBSTRATE COMPLEX