Enzymes &The Need for Energy

Enzymes &The Need for Energy

Section 1:EnzymesSection 1:Enzymes

Enzymes are CatalystsEnzymes are Catalysts

Catalysts- substances that speed up speed up chemical chemical reactions without being affected by the reactions themselves.

Enzyme- a protein that can be a catalystprotein that can be a catalyst to increaseincrease the rate of reactions by lowering the activation energy.

Catalysts- substances that speed up speed up chemical chemical reactions without being affected by the reactions themselves.

Enzyme- a protein that can be a catalystprotein that can be a catalyst to increaseincrease the rate of reactions by lowering the activation energy.

Enzymes lower AEEnzymes lower AE

Activation Energy - the amount of energy needed to start a chemical reaction

Activation Energy - the amount of energy needed to start a chemical reaction

Enzyme-Substrate SpecificityEnzyme-Substrate SpecificitySubstrateSubstrate-- molecule on which an enzyme acts

An enzyme binds to a substrate and stresses the bonds of that molecule in a way that makes a reaction more likely to occur.

SubstrateSubstrate-- molecule on which an enzyme acts

An enzyme binds to a substrate and stresses the bonds of that molecule in a way that makes a reaction more likely to occur.

Enzyme

Enzyme-Substrate SpecificityEnzyme-Substrate SpecificityThe KEY to an enzyme’s activity is its shapeshape.

Active SiteActive Site- location on an enzyme where the substrate bindsEach substrate can only bind to one enzyme.

Enzymes canbe reused!

Factors that Can Effect Enzymes

Factors that Can Effect Enzymes

1. Temperature2. pH3. Concentration of Enzyme4. Concentration of Substrate

1. Temperature2. pH3. Concentration of Enzyme4. Concentration of Substrate

Effect of Temperature on Enzymes

Effect of Temperature on Enzymes

•Raising the temperature Raising the temperature will increase the speed will increase the speed and energy of collisions and energy of collisions between molecules.

•Therefore it will increase increase the activity of the enzyme the activity of the enzyme TO A POINT! The point where the rate is the highest is called the optimum of the enzyme.

•Every enzyme has its own Every enzyme has its own optimumoptimum.

•Raising the temperature Raising the temperature will increase the speed will increase the speed and energy of collisions and energy of collisions between molecules.

•Therefore it will increase increase the activity of the enzyme the activity of the enzyme TO A POINT! The point where the rate is the highest is called the optimum of the enzyme.

•Every enzyme has its own Every enzyme has its own optimumoptimum.

Effect of pH on EnzymesEffect of pH on Enzymes•Like temperature, each each enzyme has a specific pH at enzyme has a specific pH at which it works bestwhich it works best. This is called the optimum of pHoptimum of pH. • •Enzyme pH Optimum •Lipase (pancreas) 8.0 •Lipase (stomach) 4.0 - 5.0 •Lipase (castor oil) 4.7 •Pepsin 1.5 - 1.6 •Trypsin 7.8 - 8.7 •Urease 7.0 •Invertase 4.5 •Maltase 6.1 - 6.8 •Amylase (pancreas) 6.7 - 7.0 •Amylase (malt) 4.6 - 5.2 •Catalase 7.0

•Like temperature, each each enzyme has a specific pH at enzyme has a specific pH at which it works bestwhich it works best. This is called the optimum of pHoptimum of pH. • •Enzyme pH Optimum •Lipase (pancreas) 8.0 •Lipase (stomach) 4.0 - 5.0 •Lipase (castor oil) 4.7 •Pepsin 1.5 - 1.6 •Trypsin 7.8 - 8.7 •Urease 7.0 •Invertase 4.5 •Maltase 6.1 - 6.8 •Amylase (pancreas) 6.7 - 7.0 •Amylase (malt) 4.6 - 5.2 •Catalase 7.0

DenaturationDenaturationEnzymes become denatured or denatured or

stop working at allstop working at all when exposed to high temperatures or adverse pH.

Enzymes become denatured or denatured or stop working at allstop working at all when exposed to high temperatures or adverse pH.

Effect of [Enzyme] on

Enzymatic Reactions

Effect of [Enzyme] on

Enzymatic Reactions

The rate of the rate of the reaction reaction increases increases with an increase in increase in the enzymethe enzyme

The rate of the rate of the reaction reaction increases increases with an increase in increase in the enzymethe enzyme

Effect of [Substrate] on

Enzymatic Reactions

Effect of [Substrate] on

Enzymatic Reactions

•Increasing the substrate on which the enzyme works will also increase the increase the rate of reaction rate of reaction UNTIL the all the enzymes are busy.

• •This is called the saturation pointsaturation point

•Increasing the substrate on which the enzyme works will also increase the increase the rate of reaction rate of reaction UNTIL the all the enzymes are busy.

• •This is called the saturation pointsaturation point

Section 2:The Need for Energy

Section 2:The Need for Energy

Biochemical PathwaysBiochemical Pathways

Biochemical Pathway: a series of biochemical reactions Usable energy produced by one reaction may

be stored and used in a later reaction. In most cases, this energy is stored in a

molecule called adenosine triphosphate (ATP).

Biochemical Pathway: a series of biochemical reactions Usable energy produced by one reaction may

be stored and used in a later reaction. In most cases, this energy is stored in a

molecule called adenosine triphosphate (ATP).

Structure of ATPStructure of ATP

Structure- the ATP molecule has three parts: 1. adenine (a nitrogen-containing molecule) 2. ribose (a five-carbon sugar)

The adenine bonds to ribose, forming adenosine. 3. three phosphate groups

Structure- the ATP molecule has three parts: 1. adenine (a nitrogen-containing molecule) 2. ribose (a five-carbon sugar)

The adenine bonds to ribose, forming adenosine. 3. three phosphate groups

Structure of ATPStructure of ATP

Function of ATPFunction of ATP

ATP stores energy in the bonds between the phosphate groups (high-energy bonds)

ATP stores energy in the bonds between the phosphate groups (high-energy bonds)

ATP-ADPCycleATP-ADPCycleATPase is an

enzyme that removes a phosphate from ATP to make it ADP

ATP Synthase is an enzyme that adds a phosphate to ADP to make it ATP

ATPase is an enzyme that removes a phosphate from ATP to make it ADP

ATP Synthase is an enzyme that adds a phosphate to ADP to make it ATP

ATP SynthaseATPase

ATP-ADP CycleATP-ADP Cycle

ATP Synathase ATPase

ATP-ADP CycleATP-ADP Cycle

The breakdown of ATP to ADP may result in: 1. free phosphate ions + energy.

OR 2. the transfer of a phosphate group to

another molecule (phosphorylation). The phosphorylated molecule gains both the phosphate group and the energy.

The breakdown of ATP to ADP may result in: 1. free phosphate ions + energy.

OR 2. the transfer of a phosphate group to

another molecule (phosphorylation). The phosphorylated molecule gains both the phosphate group and the energy.

Phosphorylation by ATPPhosphorylation by ATP

Phosphorylation- protein gets phospate group and enrgy

ATP-ADP CycleATP-ADP CyclePhotosynthesis, respiration, and the ATP-

ADP cycle form a fundamental biological cycle: plants store energy in glucose molecules

during photosynthesis → animals and plants release that energy during

respiration → the energy is stored in ATP → until it is

needed to fuel cell activities

Photosynthesis, respiration, and the ATP-ADP cycle form a fundamental biological cycle: plants store energy in glucose molecules

during photosynthesis → animals and plants release that energy during

respiration → the energy is stored in ATP → until it is

needed to fuel cell activities

ATP-ADP CycleATP-ADP Cycle