Download Enzymes: “Helper” Protein molecules

Enzymes
9/30/15
Regents Biology
ACT
Regents Biology
Brain Teaser
 It can’t be touched, but can be felt.
It can’t be opened, but can be gone into.
Those who seek it always find it under
something,
yet it moves from place to place
Regents Biology
Objectives
 Students will:
Identify the effects of enzymes
 Given a set of procedures and
materials, students will construct a
model of how enzymes interact with
other molecules in the body.

Regents Biology
Enzymes:
“Helper” Protein molecules
Regents Biology
2009-2010
Flow of energy through life
 Life is built on chemical reactions
Regents Biology
Our bodies are continuously:

building molecules
+
 synthesis

breaking down molecules
 digestion
Regents Biology
+
Nothing works without enzymes!
 How important are enzymes?
all chemical reactions in living
organisms require enzymes to work
 enzymes speed up chemical reactions

enzyme
 “catalysts”
 building molecules

We can’t live
without enzymes!
synthesis enzymes
 breaking down molecules

+
enzyme
digestive enzymes
+
Regents Biology
Why do we need to speed up
reactions?
 Because our bodies would never get


the nutrients they need in time without
enzymes.
Our bodies are too slow to process
chemical reactions without enzymes.
Catalyst – speeds up chemical
reactions without actually being
involved in the reaction
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Examples
 synthesis
+
enzyme
 digestion
enzyme
Regents Biology
+
Regents Biology
Enzymes are proteins
There’s an enzyme for that
 each enzyme needs to be the right shape
for the job
 enzymes are named for the reaction
they help

 sucrase breaks down sucrose
Oh, I get it!
They end
in -ase
 protase breakdown proteins
 lipases breakdown lipids
 DNA polymerase builds DNA
Regents Biology
Enzymes aren’t used up
 Enzymes are not changed by the reaction
used only temporarily
 re-used again for the same reaction with
other molecules
 very little enzyme needed to help in many
reactions

substrate
active site
Regents Biology
product
enzyme
It’s shape that matters!
 Lock & Key model

shape of protein
allows enzyme &
substrate to fit

specific enzyme
for each specific
reaction
Regents Biology
2
1
3
Regents Biology
Enzyme vocabulary
 Enzyme

helper protein molecule
 Substrate

molecule that enzymes work on
 Products

what the enzyme helps produce from
the reaction
 Active site

part of enzyme
that substrate
molecule fits into
Regents Biology
Enzyme vocabulary
 Catalyst

Substance that starts or speeds up a chemical
reaction without being in the reaction itself.
 Chemical reaction

Combination of two or more elements
chemically
 Activation energy

Minimum energy needed to start a chemical
reaction
 Denatured

Irreversibly changing the shape of a protein
Regents Biology
What affects enzyme action
 The SHAPE of the enzyme
Correct protein structure (order of
amino acids)
 Temperature
 pH (acids & bases)

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Order of amino acids
 Wrong order = wrong shape = can’t do its job!
chain of
amino acids
DNA
folded
protein
right shape!
folded
protein
chain of
amino acids
DNA
Regents Biology
wrong shape!
Temperature
 Effect on rates of enzyme activity

Optimum temperature
 greatest number of collisions between
enzyme & substrate
 human enzymes
 35°- 40°C (body temp = 37°C)
Raise temperature (boiling)
 denature protein = unfold = lose shape
 Lower temperature T°
 molecules move slower
 fewer collisions between enzyme &
Regents Biology substrate

Denatured – permanently changed
shape and not re-usable
Regents Biology
Temperature
reaction rate
human
enzymes
37°
temperature
Regents Biology
What’s
happening
here?!
How do cold-blooded creatures do it?
Regents Biology
pH
 Effect on rates of enzyme activity

changes in pH changes protein shape

most human enzymes = pH 6-8
 depends on where in body
 pepsin (stomach) = pH 3
 trypsin (small intestines) = pH 8
Regents Biology
pH
intestines
trypsin
What’s
happening
here?!
reaction rate
stomach
pepsin
0
1
2
3
4
5
6
pH
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7
8
9
10 11
12 13 14
For enzymes…
What matters?
SHAPE!
Regents Biology
2009-2010
Role of Enzymes
Regents Biology
Let’s build some
Enzyme Models!
Regents Biology
2009-2010
First define the vocabulary
 Catalyst

Substance that starts or speeds up a chemical
reaction without being in the reaction itself.
 Chemical reaction

Combination of two or more elements
chemically
 Activation energy

Minimum energy needed to start a chemical
reaction
 Denatured

Irreversibly changing the shape of a protein
Regents Biology
vocabulary
 Enzyme

helper protein molecule
 Substrate

molecule that enzymes work on
 Products

what the enzyme helps produce from
the reaction
 Active site

part of enzyme
that substrate
molecule fits into
Regents Biology
Then color the shapes
 Enzyme = PINK
 Triangular Substrate = PURPLE
 Square Substrate 1 = YELLOW
 Square Substrate 2 = BLUE
 Product 1 = BLUE
 Product 2 = RED
 Rectangular Product = GREEN
Regents Biology
Your cut-out paper
 Has parts for BOTH part B and C.
 Part B – triangular shaped pieces
 Part C – square and rectangular shaped
pieces
Regents Biology
Follow instructions for Parts B & C
1. Cut out your pieces.
2. Organize the cut-outs on construction
3.
4.
5.
paper according to the equation.
Glue them.
Label them.
Explain below what happened. Use as
many vocabulary words from Part A as
possible.
Regents Biology
Create your graph – Part D
 Use the data to draw a graph.
 Answer the questions using as many of
the vocabulary words in Part A as
possible.
Regents Biology