Micro Chapter 6 - Enzymes and Inhibition

enzyme

biological catalysts that bind to a substrate

the enzyme-substrate increases the chance for…

collision, which reduces activation energy needed

hydrolases

adds water to break bonds

hydroses

removes water to form bonds

oxidoses/dehydrogenases

works to transfer electrons and promotes redox reactions; used for separating non-lactose fermenting gram negative rods or staph species from micrococcus species

transferases

transfers radicals

demolases/lyases

used to split/form carbon to carbon bonds

isomers

changes/rearranges molecular geometry of a molecule

ligases

joining 2 molecules thru hydrolysis of pyrophosphate bonds in ATP/GTP

competitive inhibition

substrate + another substance compete for enzyme

feedback inhibition

excessive product fills activation site, limiting future substrate/enzyme reactions

non-competitive/allosteric inhibition

substances when added to the substrate alter the enzyme so it can’t accept the substrate

substrate inhibition

occurs when excess substrate is present

collision theory

all atoms, ions, and molecules are continuously moving and are always colliding

coenzymes

accept atoms removed from substrate by donating atoms the substrate needs

most enzymes are made of…

• apoenzyme = protein portion

• cofactor = non protein portion

factors influencing enzymatic activity

• exposure to heavy metals

• temperature

• pH

• substrate concentration

• inhibitors

• strength of ionic compound

catabolism

breaking down complex organic molecules to simpler ones

anabolism

building complex organic molecules from simpler ones

enzyme action step 1

substrate’s surface contacts active site

enzyme action step 2

temperature intermediate (enzyme-substrate) complex forms

enzyme action step 3

substrate molecule is transformed - existing atoms are rearranged or substrate molecules are broken down

enzyme action step 4

transformed substrate molecules are released from enzyme molecules