Warm up date 10/1Define these words

Chemical reactionReactantProductActivation energyCatalystEnzymesSubstrate

Warm up date 10/6Write the question and answer!What is the purpose of an enzyme?Describe activation energy?What is the role of a substrate?

Ms Caldarola

Biochemistry: Chemical Reactions and

Enzymes

Chemical reactionChemical reaction - a process that changes, or

transforms, one set of chemicals into anotherMass and energy is conserved during chemical

reactionReactants – elements or compounds that enter

into a chemical reactionProduct – elements or compound produced by a

chemical reaction

Chemical reactionWhat happens to chemical bonds during

chemical reaction?Chemical reactions involve changes in the

chemical bonds that join atoms in compounds

Energy Source?In order to stay alive, organisms need to carry

out reactions that require energyEx: plants trap and store energy from sunlightEx: animals must consume food to get energy

Energy in ReactionsEnergy is released or absorbed whenever

chemical bonds are formed or brokenThis means chemical reactions involve changes

in energyHow do energy changes affect whether a

chemical reaction will occur?Chemical reactions that release energy often

occur on their ownEx: burning of hydrogen gas 2H2 + O2 2H2OEnergy is released in the form of heat

Chemical reactions that absorb energy will not occur without a source of energy

Activation EnergyActivation energy – energy that is needed to get

the reaction started

Catalyst- a substance that speeds up the rebate of a chemical reaction Catalysts work by lowering the activation energy level

EnzymesWhat role do enzymes play in living things and

what affects this function?The role of enzymes is used to speed up

chemical reactions that take place in cellsEnzymes – are proteins that act as a biological

catalysts

Enzyme Substrate ComplexFor a chemical reaction to take place…

the reactants must collide with enough energy so that existing bonds will be broken and new bond will form

Enzymes provide a site where reactants can be brought together to react

Substrates – reactants of enzyme catalyzed reactions

Regulation of enzyme activityWhat can affect the activity of enzymes?

TemperaturepHRegulatory molecules

Enzymes important to the human body

Lactase - is an enzymes produced by the small intestines found in the digestive system of Humans.Lactase breaks down lactose, a simple sugar

which gives milk its sweetnessSalivary amylase -is a protein enzyme, found in

saliva and breaks starch into maltose and dextrin.amylase is most prominent in pancreatic juice

and saliva, each of which has its own isoform of human α-amylase

It will break large, insoluble starch molecules into soluble starches

Enzymes important to the human bodyProtease -is any enzyme that breaks down proteins

into smaller polypeptides or amino acidsbegins protein catabolism by hydrolysis of the

peptide bonds that link amino acids together in the polypeptide chain forming the protein

Catalase - common enzyme found in nearly all living organisms exposed to oxygen (such as vegetables, fruit or animals). It catalyzes the decomposition of hydrogen

peroxide in living tissue. It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS).