In order for chemical reactions to take place enzymes must be present to help speed up the reaction Chemical bonds connect atoms to make molecules Chemical reactions can do two things ID: 932502
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Slide1
Enzymes
Slide2Chemical Reactions
In order for chemical reactions to take place,
enzymes
must be present to help speed up the reaction.Chemical bonds connect atoms to make molecules.Chemical reactions can do two things:They can join atoms to make molecules. They can break bonds in molecules. The sum of all the chemical reactions that take place within a cell is referred to as the cell’s metabolism.
Slide3Chemical Reactions
The molecules or atoms at the beginning of a chemical reaction are called the
reactants
. The materials produced by the chemical reaction are called products. 2H2 + O2 2H2O Reactants Product
Slide4Law of Conservation of Matter/EnergyMatter and Energy cannot be created or destroyed in chemical reactions
Slide5Energy-Absorbing vs. Energy-Releasing Reactions
Energy-Absorbing
Reaction
Endothermic Reaction
Energy-Releasing Reaction
Slide6The molecules or atoms at the beginning of a chemical reactions are called ______.
Enzymes
Reactants
ProductsActive sites
Slide7Chemical reactions in which the products have more energy than the reactants are called _________ reactions.
Energy-Releasing
Energy-Absorbing
Slide8Which graph illustrates an energy-releasing reaction?
Graph A
Graph B
Slide9Introduction to Enzymes
Enzymes
are
proteins that act as biological catalysts. Catalysts - speed up chemical reactions.Enzymes- speed up chemical reactions in living things.
Slide10Structure and Function of Enzymes
A
substrate
is the molecule that the enzyme changes.It is the reactant a chemical reaction controlled by an enzyme!Each enzyme has an active site which is the place where the enzyme and substrate attach.
Slide11Structure and Function of Enzymes
During a chemical reaction, the enzyme helps the
reactant
turn into product, however, the enzyme is not changed. Enzymes can be used over and over again.Reactant/Substrate
Product
Enzyme
No change in the shape of
enzyme/ready to catalyze next reaction.
Slide12Enzymes are specific types of which biological macromolecule?
Carbohydrates
Proteins
LipidsNucleic acids
Slide13The molecule on which an enzyme acts:
Catalyst
Substrate
MetabolismHomeostasis
Slide14Which shape is the enzyme?
A
B
CD
A
A
A
B
C
D
D
Slide15Which shape is the product of the chemical reaction shown below?
A
B
CD
A
A
A
B
C
D
D
Slide16Enzyme Specificity
Enzymes are very
specific
. This means that each enzyme can only work on one substrate.For example:1. Maltase only breaks down maltose (a carbohydrate).2. Lipase only works on certain lipids. 3. Protease only works on certain proteins.Does a specific enzyme work on more than one substrate? NO!!!
Slide17Enzyme Specificity
Therefore you need
thousands of
different enzymes for the thousands of different chemical reactions in your body. The names of many enzymes (Amylase, Lipase, Pepsin, Trypsin) usually end in ase or in.
Slide18Enzyme Specificity
The diagram below shows
the
lock and key model of how enzymes work on a specific substrate.Just like every lock has one type of key that opens it, every substrate has one type of enzyme that works on it.
Slide19How Enzymes Work
Lower
activation energy
Energy that is needed to start a chemical reaction Puts substrates in a good position to make/break bonds with each other
Slide20Reaction with enzyme vs. Reaction without enzyme
Slide21The energy that is required to start a chemical reaction is called
Endothermic energy
Exothermic energy
Enzyme energyActivation energy
Slide22How do catalysts speed up or facilitate chemical reactions?
Lower the activation energy
Add energy to the reaction
Break hydrogen bonds in the chemicalsDecrease the number of reactants
Slide23Enzymes lower activation energy
Slide24Enzymes and Their Environment
Most cells function best within a narrow range of
temperature
and pH. At very low temperatures, enzymes work too slow.
Slide25Enzymes and Their Environment
At
high temperatures or extremes of pH
the enzymes lose their shape.What would happen if a key lost its shape? It wouldn’t turn or fit in the hole. What will happen if an enzyme lost its shape?It wouldn’t recognize or bind with it’s substrate.
Slide26Enzymes and Their Environment
When an enzyme loses its shape and can no longer work correctly, it has been
denatured
.
Slide27Enzymes stop functioning if:
They act on a substrate
They become denatured due to improper pH or temperature
They catalyze too many reactionsThey bind with the wrong substrate
Slide28When proteins, such as enzymes, lose their specific shape they have become __________.
Passive
Endothermic
ExothermicDenatured
Slide29What is the optimum pH for the enzyme pepsin?
1
2.5
56.5
pepsin
trypsin
Slide30Introduction to Macromolecules
Slide31Building Macromolecules
Polymer
– large biomolecules made by linking together a large number of the same type of subunit
Monomer- small molecule that is a subunit of a polymer (building blocks)Chemical reactions link monomers together to build polymers or break down polymers into monomersEnzymes help speed up these reactions!!
Slide32Organic Macromolecules (Polymers)
MONOMER
POLYMER
Amino AcidProteinSugar(monosaccharide)Carbohydrate(polysaccharide)NucleotideNucleic Acid
Slide33Polymers are large biomolecules made of repeated subunits called
Enzymes
Sugars
MonomersProteins
Slide34Proteins are polymers made of monomers called
Monosaccharides
Fatty acids
Amino acidsnucleotides