Do Now (on index cards)
• Without looking at your
notes…
What are the four
macromolecules and their
function(s)?
Standards
• SB1B: Explain how enzymes function as
catalysts.
• SB1: Students will analyze the nature of the
relationships between structures and
functions in living cells.
• SBSh2b: Demonstrate appropriate technique
in all laboratory situations.
Do Now
• Define the following using the textbook:
- enzyme
- catalyst
• Any factor that changes the shape of an enzyme
can affect the enzyme’s activity. Which of the
following two factors affect an enzymes
operation the most?
A) temperature and pH
B) amount of light and temperature
C) blood glucose level and pH
D) amount of light and pressure
Do Now 1/21/15
Reusable, complex proteins that promote chemical
reactions within cells are called:
A) Enzymes
B) Inhibitors
C) Regulators
D) Steroids
Take out notes for organelles and cell types, cootie
catcher, macromolecules cube, and pH. STUDY!!
Quiz Procedures
• Fill in your name and lunch number on the
bubble form.
• Do not mark anywhere but the bubble.
• Must write in pencil.
• NO TALKING OR LEAVING SEAT!
• After you finish, check your work, flip it over and
wait silently until I collect all the tests.
• If you talk while any test is out, I assume you are
cheating and you will receive a zero.
Enzymes
Follow along on your note sheet.
Do-Now
• Define metabolism.
• Read page 52-53 in textbook.
• Answer questions 2-3 on page 53 (all parts).
Why eat?
From food to fuel.
• All cells help maintain homeostasis by
developing metabolic pathways.
• A metabolic pathway is an orderly sequence of
reactions with specific enzymes that act at
each step along the way.
ENERGY
EAT FOOD
Enzyme Reactions
What are enzymes?
• Enzymes are
catalytic
molecules.
• That is, they speed
up specific
reactions without
being used up in
the reaction.
• Enzymes are
proteins.
All enzymes share 3 features:
1. Enzymes speed up reactions.
2. Enzymes are not permanently altered or used
up in reactions. They can be reused.
3. They are specific to one type of reaction.
Enzymes
• Substrates are molecules that a specific
enzyme can chemically recognize and to
which it can bind (connect with).
• Substrates undergo chemical changes to form
new substances called products.
Lock-and-Key Model
• Each substrate fits into an area of the enzyme
called the active site.
• It is like a lock-and-key mechanism.
Speed up!
• The rate of a reaction depends in part on the
concentration of the enzyme.
• More enzyme…. Faster reaction…
With an enzyme, reactions need less energy.
This is called activation energy.
Up the hill…
• It is like traveling over a hill.
• The lower the hill, the less energy it takes to
get to the top, and the faster you can go over
it.
• The higher the hill, the more energy it takes to
get to the top and the longer it will take you to
go over it.
Closing