Transcript Enzymes
Word of the day
• Catalyst:
– A substance that increases the speed of a
chemical reaction AND lowers the amount of
energy needed
Agenda
Latin and Greek Quiz
Enzyme Notes
Enzyme Study Tool
Review
• There are four macromolecules
–
–
–
–
Carbohydrates
Lipids
Nucleic acids
Proteins
• Monomer: amino acids
• Polymer: polypeptide chains
Let’s study one protein:
Enzymes
What do Enzymes do?
• Our body makes many
enzymes
• Enzymes are specialized
proteins that breakdown
or combine molecules
into things our cells need
Catalysts
Catalysts: decrease (lowers) the amount of energy needed to start a
reaction (activation energy).
Enzyme = catalyst
Each enzyme is specific to a
reaction
Ex: Lipase, Protease, Amylase, Lactase, Sucrase, Catalase
(Think of a Lock & Key)
Enzyme Animation
• http://highered.mheducation.com/sites/0072
495855/student_view0/chapter2/animation_
_how_enzymes_work.html
In our lab toothpickase…
• What represented
the enzyme?
• What represented
the substrate?
• What represented
the product?
Induced Fit Model
• The active site on
the enzyme is
temporarily
reshaped each
time the
molecules bind
Like a lock and a key – that you
have to jiggle
How do Enzymes Work?
1. A substrate(s) fits into a active site on the enzyme.
2. The enzyme lowers the energy required to complete the reaction.
3. The product is released by the enzyme.
Factors that affect rates of enzymes:
1. Temperature—work best at body temp.
Cold = slow, Hot = denatured (change shape)
2. Concentration of enzyme--more enzymes to do the work
= faster
3. Concentration of substrate—more to work on = the
slower it goes
4. Competition with inhibitors—other substances (ex:
drugs) block active site = they work slower
5.
pH—each enzyme has a “best” pH. Out of that range
they denature.
In our toothpickase lab…..
• What did we do that showed enzyme
concentration?
• What did we do to show substrate
concentration?
• What did we do to represent the
environment?
Denatured Enzyme
• Definition: a change in the shape of the enzyme molecule
making the enzyme useless or less effective.
• The substrate no longer “fits” into its’ Active Site.
• Substrate does not fit
enzyme does not work
Enzyme Animations
• http://www.kscience.co.uk/animations/anim
_2.htm
Can you……..?
• Define the key words: enzyme, catalysts,
substrate, active site, activation energy,
products, denatured and substrate specific
• Describe how an enzyme works.
• Describe factors that affect enzymes.
An
Enzyme
in Action
Can you describe
what is happening
here?
Active
Site
Which would be the
substrate and
product for this
enzyme?
Substrate 1 and products 3/4
P1
Substrate 1
P2
Product
Substrate 2
P3
Assignment
• Make a study tool
– Must have the word or concept
– Must have a picture representing the
word/concept
– Must have a written definition of the
word/concept