Section 2.4 Enzymatic reactions
Formative assessment
1. An enzyme is what type of molecule?A. CarbohydrateB. LipidC. Nucleic acidD. ProteinE. Sugar
Carbohyd
rate
Lipid
Nucleic
acid
Protein
Sugar
0% 0% 0%0%0%
2. Cells need enzymes because they:A. Speed up chemical
reactions for their particular substrate
B. Act as biological (organic) catalysts
C. Lower activation energy, making the reaction more likely to start
D. A and BE. A, B, and C
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3. Activation energy is :A. Chemical potential energy
stored in the substrate
B. Chemical potential energy stored in the product
C. Energy released after the chemical reaction
D. Energy needed to start the chemical reaction
E. Energy needed to allow the substrate to bind to the active
site.Chemica
l pote
ntial energ.
..
Chemical p
otential e
nerg...
Energy r
eleased after t
he...
Energy n
eeded to st
art t..
Energy n
eeded to allo
w t..
0% 0% 0%0%0%
5. Which part of the graph shows the activation energy for the enzyme catalyzed reaction?
A. AB. BC. CD. D
A B C D
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AD
C
B
6. The part of an enzyme where substrate binds is?
A. ProductB. Active siteC. Enzyme substrate
complexD. ProteinE. Sugar
Product
Active
site
Enzyme su
bstrate
complex
Protein
Sugar
0% 0% 0%0%0%
7. All enzymes require an optimal pH, salt concentration, and temperature because under other conditions the protein may _____?
A. Be denatured.B. Be converted to a
carbohydrate.C. Be broken down to
amino acids.D. Be converted to a lipid.E. Be too active as a
catalyst.Be denatu
red.
Be conve
rted to
a carb
o...
Be broke
n down to am
in...
Be conve
rted to
a lipid.
Be too acti
ve as a ca
talys
t.
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8. Which is(are) the reactants of the chemical reaction described in this chemical equation ? C12H22O11 + H2O 2C6H12O6
A. C12H22O11
B. C12H22O11 & H2O
C. C6H12O6
D. H2O and C6H12O6
E. C12H22O11 & H2O & C6H12O6
C12H22O11
C12H22O11 & H
2O
C6H12O6
H2O and C6H12O6
C12H22O11 & H
2O
0% 0% 0%0%0%
9. When they are bound to an enzyme, thereactants of a chemical equation are called:
A. ProductsB. Active sitesC. Substrates
Products
Active
sites
Substrate
s
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10 Enzymes are specific types of which biological macromolecule?
A. CarbohydratesB. ProteinsC. LipidsD. Nucleic acids
Carbohyd
rates
Proteins
Lipids
Nucleic
acids
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11 The molecule on which an enzyme acts:
A. CatalystB. SubstrateC. MetabolismD. Homeostasis
Catalys
t
Substrate
Meta
bolism
Homeostasis
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12 Enzymes stop functioning if:
A. They act on a substrate
B. They become denatured due to improper pH or temperature
C. They catalyze too many reactions
D. They bind with the wrong substrate They a
ct on a su
bstrate
They beco
me denatured...
They cata
lyze to
o many ...
They bind w
ith th
e wro
..
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13 When proteins, such as enzymes, lose their specific shape they have become __________.
A. PassiveB. EndothermicC. ExothermicD. Denatured
Passiv
e
Endotherm
ic
Exoth
ermic
Denatured
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14 What is the optimum pH for the enzyme pepsin, the stomach enzyme that digests protein?
A. 1B. 2.5C. 5D. 6.5
0% 0% 0% 0%0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1 2.5 5 6.5
pepsin trypsin
15 What is the optimum pH for the enzyme trypsin, the small intestinal enzyme that digests protein?
A. 1B. 2.5C. 5D. 6.5
0% 0% 0% 0%0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1 2.5 5 6.5
pepsin trypsin
16 Examine the graph of enzyme activity versus temperature, then choose the most probable explanation of the data.
A. The enzyme whose rate is shown in blue has optimal activity at 37°C but is denatured at 4°C
B. The enzyme shown in red has a optimal temperature of 37°C, but is denatured at 4°C
C. The organism which uses the enzyme shown in blue is likely to be a mammal, but the enzyme shown in green is likely an extremophile bacterium that lives in a geyser
D. The enzyme shown in red has an optimal temperature of 37°C, but is denatured at 95°C and has too little activation energy at 4 °C
The enzyme w
hose ra
te i..
.
The enzyme sh
own in re
...
The organism
which
uses..
.
The enzyme sh
own in re
...
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17 Why won’t the enzyme that breaks down sucrose also break down maltose?
A. Organisms who eat sucrose don’t eat maltose
B. Maltose is rareC. The enzyme that
breaks down sucrose is denatured at the pH where maltose is active
D. The substrate maltose has the wrong shape so can’t fit the active site of the sucrose digesting enzyme
Organism
s who eat s
ucr...
Malto
se is
rare
The enzyme th
at bre
aks...
The substr
ate m
altose
h..
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18 Lactase is likely:
A. An enzyme that digests lactose
B. A carbohydrate found in milk
C. A protein found in milk
D. An enzyme that digests sucrose
An enzyme th
at dige
sts l..
.
A carb
ohydrate
found in
...
A prote
in found in
milk
An enzyme th
at dige
sts s.
..
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19 Which is NOT true of all enzymes?
A. All enzymes have an optimal pH of 7 & optimal temperature of 37°C
B. All enzymes are specific for a particular substrate because of the shape of the active site
C. All enzymes are re-useable unless they become denatured
D. All enzymes can be denatured when physical conditions are extremely different from their normal conditions
All enzy
mes have an
opt...
All enzy
mes are sp
ecific f
..
All enzy
mes are re
-useab..
All enzy
mes can
be dena...
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Building 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 monomers– Enzymes help speed up these reactions!!
Organic Macromolecules (Polymers)
MONOMER POLYMER
Amino Acid Protein
Sugar(monosaccharide)
Carbohydrate(polysaccharide)
Nucleotide Nucleic Acid
https://www.youtube.com/watch?v=hzFn3jH1tK0 potato catalase enzyme activity lab video—pH
https://www.youtube.com/watch?v=0nwI0xnG8W4 Enter Answer Text
Enter A
nswer T
ext
100%
Polymers are large biomolecules made of repeated subunits called
A. EnzymesB. SugarsC. MonomersD. Proteins
Enzymes
Sugars
Monomers
Proteins
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