Agenda:
1. High-Yield Science: Enzyme Kinetics
2. Science Passage Strategy
3. Science Questions: Type and Rephrase
4. Science Questions: Investigate and Match
In this lesson, you’ll learn to:
•
Explain the significance of key aspects of the double-reciprocal Lineweaver–
Burk format, including axes, intercepts, units, and slopes
•
Identify Vmax and Km on both Michaelis–Menten and Lineweaver–Burk plots
•
Plot the effects of competitive inhibition on both graph types
Enzyme activity is often graphed using a Michaelis–Menten plot. However, enzyme activity may
also be graphed using an alternative format, the Lineweaver–Burk plot. HMG-CoA reductase is the
rate-limiting enzyme of cholesterol synthesis. Statins, such as atorvastatin (Lipitor), simvastatin
(Zocor), and rosuvastatin (Crestor) are routinely used to treat patients with high cholesterol because
they are competitive inhibitors of HMG-CoA reductase. How would the use of a statin affect the
Lineweaver–Burk plot of HMG-CoA reductase?
A Michaelis–Menten plot clearly shows the asymptotic behavior of a plot
of an enzyme’s kinetics. What is the plot’s basic shape? How does it
display KM and Vmax?
Reaction Velocity
Substrate Concentration [S]
V (s/µmol)
A Lineweaver–Burk plot shows the same information as a Michaelis–
Menten plot. How does it display KM and Vmax? What are the benefits of a
Lineweaver–Burk plot, compared to a Michaelis–Menten plot?
1
Needs
Review
1
[S]
(mM–1)
Why does a competitive inhibitor increase an enzyme’s KM while leaving
its Vmax unchanged?
V (s/µmol)
A competitive inhibitor will have the effect of increasing the slope of a
Lineweaver–Burk plot. Why?
1
Needs
Review
1
[S]
(mM–1)
A competitive inhibitor will have the effect of increasing the slope of a
Lineweaver–Burk plot. Why?
Reaction Velocity
Needs
Review
Substrate Concentration [S]
Reflect: What are 3 things from this lesson you recalled and what are 3
things you need to review more?
I knew:
I need to review:
1.
1.
2.
2.
3.
3.
The content in this lesson can be found in Biochemistry Review Chapter 2:
Enzymes.
In this lesson, you’ll learn to:
• Preview a science passage at a glance,
determining likely topic and difficulty
• Utilize the highlight, outline and
interrogation methods as they apply to
science passages
Science Topics
• Organic Chemistry Reactions (Organic
Chemistry Review Chapter 1)
• Biology and Behavior (Behavioral Sciences
Review Chapter 1)
• Translation (Biochemistry Review Chapter 7)
Science
Knowledge
MCAT
Expertise
MCAT
Science
Science
Knowledge
Skills
Data and
Statistical
Analysis
Scientific
Reasoning
and
Problem
Solving
Experimental
and Research
Design
MCAT Strategy—Science Passages
PREVIEW
for difficulty
Decide whether to read the passage now or later
CHOOSE
your approach
Decide whether you will Highlight, Outline, or Interrogate
the passage
READ and DISTILL
the meaning of
each paragraph
Use keywords and science terms to identify the most
important and testable content, and use the approach
you choose to extract major takeaways from each
paragraph
Needs
Review
In this section, you’ll learn to:
• Preview a science passage at a glance, determining likely topic and difficulty
Practice Passage 1 – Chem/Phys
Styrene is used extensively in the manufacture of plastics, rubber, and resin. It is a colorless liquid with a
sweet, aromatic odor at low concentrations and a sharp, disagreeable odor at high concentrations.
Because its metabolite is reactive, styrene is classified as a mutagen. Studies have not yet proven
definitively that exposure leads to cancer, but a causal link is strongly suspected; the U.S. National
Toxicology Program describes styrene as “reasonably accepted to be a human carcinogen.”
Styrene can be synthesized in the lab either by reacting sulfuric acid with compound A (1-phenylethanol),
characterized by a mild hyacinth odor, or using zinc metal with compound B (1-phenyl-1,2
dibromoethane) in ethanol; Compound B can be synthesized by generating Br2 gas in situ from the
reaction of potassium bromate and hydrobromic acid and irradiation with a lamp. The preferred method
for styrene production on an industrial scale involves taking compound C (ethylbenzene) through a
dehydrogenation reaction catalyzed by an amalgam of iron(III) oxide and potassium carbonate.
Needs
Review
Practice Passage 2 – Psych/Soc
In evolutionary psychology, a supernormal stimulus, or “superstimulus,” is an evolutionarily novel
concentration of engaging factor that produces a stronger response than a typical one. Certain systems
that govern the reaction to rewarding stimuli can be overloaded and their negative feedback component
overridden. This hypothesis provides explanations for the number of excessive behaviors in society, often
conceptualized as “behavioral addictions:” drug addiction, internet addiction, food addiction, and so on.
The neurocircuitry and endocrinology underlying hunger and satiety may represent the best studied
system in this regard. They clearly produce a physiological balance under certain conditions with regular
stimulus, such as when a laboratory mouse fed rodent chow its whole life maintains a normal weight, but
are dysregulated in other conditions that contain superstimuli, such as when that mouse fed a high-fat,
high-carbohydrate diet becomes obese. The signals that encode hunger and satiety alter the brain’s
dopaminergic reward system in multiple ways, affecting hypothalamic neurocircuits and neuropeptides in
combination with peripheral hormones, to modulate midbrain dopaminergic activity and alter reward
value.
Ghrelin, a peptide hormone produced in the stomach, allows for preferential promotion of food-seeking
and food-consuming behavior. It also increases the amplitude of dopamine release via AgRP/NPY
neurons (agouti-related peptide/neuropeptide Y). Finally, by acting on the hippocampus, ghrelin promotes
dopamine induced synaptic plasticity and future silencing of the reward cue.
Needs
Review
Practice Passage 3 – Bio/Biochem
It is well established that 1α(OH)2D3 (1,25D3), the active metabolite of vitamin D, negatively affects
breast cancer cells by inhibiting cell proliferation and curtailing invasiveness, both through apoptosis and
potentiating differentiation. 1,25D3 downregulates estrogen receptor α expression and inhibits estrogenmediated signalling in these cells Furthermore, lower circulating levels of vitamin D in women have
been positively linked with enhanced breast cancer risk and disease mortality.
Vitamin D action is mediated by the nuclear receptor and transcription factor Vitamin D receptor (VDR).
A polymorphism in the VDR gene found on exon 2 in the 5' coding region results in different translation
initiation sites. A thymine (T) to cytosine (C) conversion in the first translation initiation codon ATG
generates long and short variants of VDR. In the VDRff variant, initiation of translation occurs at the first
ATG site, giving rise to a full-length VDR protein comprised of 427 amino acids. Conversely, in the
VDRFF variant, translation begins at the second ATG site, resulting in a truncated protein with three
fewer amino acids. Researchers have proposed that this polymorphism may be implicated in the
differential response to vitamin D treatment for breast cancer.
MCF-7 cells with transfected vector, VDRff, or VDRFF were treated with estradiol in the presence or
absence of 1,25D3 for 4 days and dyed with crystal violet. Absorbance at 570 nm was used to assay for
cell proliferation. The results are displayed below (** indicates p <0.01).
Adapted from: Alimirah, F, Peng, X, Murillo, G, Mehta, RG (2011). Functional significance of vitamin D receptor FokI
polymorphism in human breast cancer cells. PLoS One. 6(1): e16024. doi:10.1371/journal.pone.0016024.
Needs
Review
In this section, you’ll learn to:
• Utilize the highlight, outline and interrogation methods as they apply to
science passages
Practice Passage 1 – Highlight
Styrene is used extensively in the manufacture of plastics, rubber, and resin. It is a colorless liquid with a
sweet, aromatic odor at low concentrations and a sharp, disagreeable odor at high concentrations.
Because its metabolite is reactive, styrene is classified as a mutagen. Studies have not yet proven
definitively that exposure leads to cancer, but a causal link is strongly suspected; the U.S. National
Toxicology Program describes styrene as “reasonably accepted to be a human carcinogen.”
Styrene can be synthesized in the lab either by reacting sulfuric acid with compound A (1-phenylethanol),
characterized by a mild hyacinth odor, or using zinc metal with compound B (1-phenyl-1,2
dibromoethane) in ethanol; Compound B can be synthesized by generating Br2 gas in situ from the
reaction of potassium bromate and hydrobromic acid and irradiation with a lamp. The preferred method
for styrene production on an industrial scale involves taking compound C (ethylbenzene) through a
dehydrogenation reaction catalyzed by an amalgam of iron(III) oxide and potassium carbonate.
Needs
Review
Practice Passage 2 – Outline
In evolutionary psychology, a supernormal stimulus, or “superstimulus,” is an evolutionarily novel
concentration of engaging factor that produces a stronger response than a typical one. Certain systems
that govern the reaction to rewarding stimuli can be overloaded and their negative feedback component
overridden. This hypothesis provides explanations for the number of excessive behaviors in society, often
conceptualized as “behavioral addictions:” drug addiction, internet addiction, food addiction, and so on.
The neurocircuitry and endocrinology underlying hunger and satiety may represent the best studied
system in this regard. They clearly produce a physiological balance under certain conditions with regular
stimulus, such as when a laboratory mouse fed rodent chow its whole life maintains a normal weight, but
are dysregulated in other conditions that contain superstimuli, such as when that mouse fed a high-fat,
high-carbohydrate diet becomes obese. The signals that encode hunger and satiety alter the brain’s
dopaminergic reward system in multiple ways, affecting hypothalamic neurocircuits and neuropeptides in
combination with peripheral hormones, to modulate midbrain dopaminergic activity and alter reward
value.
Ghrelin, a peptide hormone produced in the stomach, allows for preferential promotion of food-seeking
and food-consuming behavior. It also increases the amplitude of dopamine release via AgRP/NPY
neurons (agouti-related peptide/neuropeptide Y). Finally, by acting on the hippocampus, ghrelin promotes
dopamine induced synaptic plasticity and future silencing of the reward cue.
Needs
Review
Practice Passage 3 – Interrogate
It is well established that 1α(OH)2D3 (1,25D3), the active metabolite of vitamin D, negatively affects
breast cancer cells by inhibiting cell proliferation and curtailing invasiveness, both through apoptosis and
potentiating differentiation. 1,25D3 downregulates estrogen receptor α expression and inhibits estrogenmediated signalling in these cells Furthermore, lower circulating levels of vitamin D in women have
been positively linked with enhanced breast cancer risk and disease mortality.
Vitamin D action is mediated by the nuclear receptor and transcription factor Vitamin D receptor (VDR).
A polymorphism in the VDR gene found on exon 2 in the 5' coding region results in different translation
initiation sites. A thymine (T) to cytosine (C) conversion in the first translation initiation codon ATG
generates long and short variants of VDR. In the VDRff variant, initiation of translation occurs at the first
ATG site, giving rise to a full-length VDR protein comprised of 427 amino acids. Conversely, in the
VDRFF variant, translation begins at the second ATG site, resulting in a truncated protein with three
fewer amino acids. Researchers have proposed that this polymorphism may be implicated in the
differential response to vitamin D treatment for breast cancer.
MCF-7 cells with transfected vector, VDRff, or VDRFF were treated with estradiol in the presence or
absence of 1,25D3 for 4 days and dyed with crystal violet. Absorbance at 570 nm was used to assay for
cell proliferation. The results are displayed below (** indicates p <0.01).
Adapted from: Alimirah, F, Peng, X, Murillo, G, Mehta, RG (2011). Functional significance of vitamin D receptor FokI
polymorphism in human breast cancer cells. PLoS One. 6(1): e16024. doi:10.1371/journal.pone.0016024.
Lesson Review
PREVIEW for difficulty
• Decide whether to read the passage now or later
CHOOSE your approach
• Decide whether you will highlight, outline or interrogate the passage
READ for keywords
• Use keywords and science terms to identify the most important and testable
content
DISTILL the meaning
• Use the approach you choose to extract major takeaways from each
paragraph
Reflect: What are 3 things from this lesson you recalled and what are 3
things you need to review more?
I knew:
I need to review:
1.
1.
2.
2.
3.
3.
The content in this lesson can be found in Organic Chemistry Review Chapter 1:
Nomenclature, Behavioral Sciences Review Chapter 1: Biology and Behavior,
and Biochemistry Review Chapter 7: RNA and the Genetic Code.
In this lesson, you’ll learn to:
• Identify the question type using the question stem and answer choices
• Rephrase the question stem to determine the task(s) to be carried out
Science Topics
• Amino Acids, Peptides, and Proteins
(Biochemistry Review Chapter 1)
• Enzyme Structure, Function, and Regulation
(Biochemistry Review Chapter 2)
• Nucleic Acid Structure and Function
(Biochemistry Review Chapter 6)
• Transcription and Translation (Biochemistry
Review Chapter 7)
Science
Knowledge
MCAT
Expertise
MCAT
Science
Science
Knowledge
Skills
Data and
Statistical
Analysis
Scientific
Reasoning
and
Problem
Solving
Experimental
and Research
Design
TYPE the question
Use the question stem and answer choices to identify the
question type and difficulty and decide whether to do it
now or later
REPHRASE the
stem
Simplify the phrasing of the question stem to determine
the specific tasks required to answer it
INVESTIGATE
potential
solutions
Use prior knowledge and the passage, if necessary, to
predict what you can about the answer
MATCH your
prediction to an
answer choice
Look for an answer choice that is synonymous with your
prediction
Needs
Review
Type By:
• Reading the question AND answers
• Identifying the question type and difficulty
• Deciding to attack now or later
Look in the question stem and answer choices for:
• Science “buzzwords”
• Passage references (e.g., “paragraph 3,” “Experiment 2”)
• Length, complexity, and structure
• Numbers or formulas
• Common question and answer patterns
Using what you find, determine:
• The science being tested
• How hard the question will be for you
• How long the question will take you
Rephrasing a Science Question
• Determine the task to be accomplished based on the question type
• Simplify the phrasing of the original question stem
• Translate the question into specific pieces of information you either know or
can locate in the passage
Needs
Review
Question Stem
A scientist has an unknown sample of an amino
acid that has been determined to have an amino
group, a carboxyl group, optical activity, and
multiple amino groups on its side chain. Of the
following values, its most likely isoelectric point
is:
The different antigenic blood types (A, B, and
O) are inherited through allelic genes. The
actual molecular difference between two blood
types is in the carbohydrate that is attached to a
common molecular backbone. The best
explanation for how genes determine blood
type, therefore, is that each gene:
A mixture composed of four organic
compounds:
pentanone, pentane, pentanoic acid, and ethanol,
is separated by column chromatography using
silica gel with cyclohexane as the eluent. What
is the most likely order of elution of the four
compounds, from first to last?
A scientist uses a fluorescent marker to tag a
large protein before placing it near a
macrophage. Once the macrophage
phagocytoses the protein, which of the
following organelles will most likely fluoresce
when viewed under a microscope?
Rephrase
Needs
Review
1. If a point mutation occurs that changes one nucleotide in an
mRNA molecule, the final protein product is LEAST likely
to be affected if the altered nucleotide is in the
A.
B.
C.
D.
original start codon.
original stop codon.
first letter of a codon.
third letter of a codon.
2. Which set of graphs best depicts the optimal
temperature and pH range for pepsin activity?
A.
B.
C.
D.
Needs
Review
3. A segment of a DNA strand has the base sequence:
5′—GTTCATTG—3′
What would be the base sequence of the RNA
strand transcribed from this DNA?
A.
B.
C.
D.
5′—CAATGAAC—3′
5′—GTTCATTG—3′
5′—CAAUGAAC—3′
5′—CAAGUAAC—3′
4. Which of the following is a possible interpretation of the
repetitive nerve stimulation studies in Figure 1?
A. People with Lambert–Eaton myasthenic
syndrome experience increasing weakness
with repetitive stimulation.
B. People with myasthenia gravis experience
increasing weakness with repetitive nerve
stimulation.
C. People with myasthenia gravis experience
decreasing weakness with repetitive nerve
stimulation.
D. People with Lambert–Eaton myasthenic
syndrome experience slower nerve conduction
than people with myasthenia gravis.
Needs
Review
5. Which of the following is the most likely reason
for the production of faulty prelamin A in
individuals with progeria?
A. The mutation causes a termination sequence
in the DNA to appear earlier than is normal.
B. The point mutation causes a stop codon to
appear earlier in protein sequencing than is
normal.
C. The DNA splices and reforms at the lamin A
gene, removing part of the protein’s template
strand.
D. The protein that is sequenced from prelamin
A is less stable as a result of the mutation, and
it denatures.
Lesson Review
When Typing the question, look in the question stem and the answer
choices for:
•
•
•
•
•
•
•
Science “buzzwords”
Passage references (e.g., “paragraph 3,” “Experiment 2”)
Length, complexity, and structure
“Yes/No” patterns in the answer choices
Numbers or formulas
Figures, tables, or other graphics
Anything else that has made similar questions easy, hard, or otherwise
notable for you in the past
Using what you find, determine:
•
•
•
•
The science being tested
How hard the question will be for you
How long the question will take you
Whether you should skip the question for now
Then, Rephrase the question stem to determine the task(s) to be carried
out by:
• Eliminating any extraneous information, or “fluff”
• Identifying the core topic(s) being tested
So you can decide:
• Whether content knowledge is enough to answer the question
• Whether you require additional information from the passage
• The steps required to convert the relevant information into a viable
prediction
Use your experience with similar questions to avoid mistakes.
Reflect: What are 3 things from this lesson you recalled and what are 3
things you need to review more?
I knew:
I need to review:
1.
1.
2.
2.
3.
3.
The content in this lesson can be found in Biochemistry Review Chapter 1:
Amino Acids, Peptides, and Proteins , Biochemistry Review Chapter 2: Enzyme
Structure, Function, and Regulation , Biochemistry Review Chapter 6: DNA and
Biotechnology, and Biochemistry Review Chapter 7: RNA and the Genetic Code
In this lesson, you’ll learn to:
• Determine the best method to investigate potential solutions
• Make strong predictions for MCAT style questions
• Match your prediction to an answer choice
Science Topics
• Amino Acids, Peptides, and Proteins
(Biochemistry Review Chapter 1)
• Enzyme Structure, Function, and Regulation
(Biochemistry Review Chapter 2)
• Nucleic Acid Structure and Function
(Biochemistry Review Chapter 6)
• Transcription and Translation (Biochemistry
Review Chapter 7)
Science
Knowledge
MCAT
Expertise
MCAT
Science
Science
Knowledge
Skills
Data and
Statistical
Analysis
Scientific
Reasoning
and
Problem
Solving
Experimental
and Research
Design
TYPE the question
Use the question stem and answer choices to identify the
question type and difficulty and decide whether to do it
now or later
REPHRASE the
stem
Simplify the phrasing of the question stem to determine
the specific tasks required to answer it
INVESTIGATE
potential
solutions
Use prior knowledge and the passage, if necessary, to
predict what you can about the answer
MATCH your
prediction to an
answer choice
Look for an answer choice that is synonymous with your
prediction
Needs
Review
In this section, you’ll learn to:
•
Determine the best method to investigate potential solutions
Investigate and Match by:
• Deciding whether to refer back to the passage
• Determining whether you can make a focused prediction
• Matching to the correct answer or eliminating the incorrect answers
1. Which of the following statements about
DNA methylation is the most accurate?
2. Polymerase chain reaction amplifies DNA
by first unwinding it using heat rather than
DNA helicase. What bonds must be broken
in order for this reaction with heat to
proceed?
3. Which of the following can be inferred from
the passage?
4. Which of the following processes is
demonstrated in the regulation of enzyme A,
as described in the passage?
5. A person has a mutation in the promoter site
of the gene for the lactase enzyme,
rendering the promoter site nonfunctional.
What symptom(s) will occur?
I. Less digestion of lactose by the person
II. More digestion of lactose by the person’s
symbiotic gut bacteria
III. Malnutrition due to glucose deficiency
Needs
Review
6. If a point mutation occurs that changes one nucleotide in an
mRNA molecule, the final protein product is LEAST likely
to be affected if the altered nucleotide is in the
A.
B.
C.
D.
original start codon.
original stop codon.
first letter of a codon.
third letter of a codon.
7. Which set of graphs best depicts the optimal
temperature and pH range for pepsin activity?
A.
B.
C.
D.
Needs
Review
8. A segment of a DNA strand has the base sequence:
5′—GTTCATTG—3′
What would be the base sequence of the RNA
strand transcribed from this DNA?
A.
B.
C.
D.
5′—CAATGAAC—3′
5′—GTTCATTG—3′
5′—CAAUGAAC—3′
5′—CAAGUAAC—3′
9. Which of the following is a possible interpretation of the
repetitive nerve stimulation studies in Figure 1?
A. People with Lambert–Eaton myasthenic
syndrome experience increasing weakness
with repetitive stimulation.
B. People with myasthenia gravis experience
increasing weakness with repetitive nerve
stimulation.
C. People with myasthenia gravis experience
decreasing weakness with repetitive nerve
stimulation.
D. People with Lambert–Eaton myasthenic
syndrome experience slower nerve conduction
than people with myasthenia gravis.
Needs
Review
10. Which of the following is the most likely reason
for the production of faulty prelamin A in
individuals with progeria?
A. The mutation causes a termination sequence
in the DNA to appear earlier than is normal.
B. The point mutation causes a stop codon to
appear earlier in protein sequencing than is
normal.
C. The DNA splices and reforms at the lamin A
gene, removing part of the protein’s template
strand.
D. The protein that is sequenced from prelamin
A is less stable as a result of the mutation, and
it denatures.
Needs
Review
In this section, you’ll learn to:
• Make strong predictions for MCAT style questions
• Match your prediction to an answer choice
Practice Passage (Questions 11–15)
Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease that affects one in eight million
live births. Individuals with progeria exhibit symptoms of aging at an early age and generally only live
until their teenage years or, occasionally, their early 20s. Affected individuals experience stunted growth,
musculoskeletal degeneration, loss of hair, and have a characteristic appearance.
Progeria typically results from a point mutation in position 1824 of the LMNA gene coding for lamin A.
A cytosine is replaced with a thymine, resulting in a shortened mRNA transcript that codes for a faulty
version of unprocessed prelamin A. During post-translational processing, prelamin A is incapable of
losing its farnesyl group (a 15-carbon isoprenoid), preventing the conversion of prelamin A to mature
lamin A. Figure 1 shows the post-translational processing that results in mutant prelamin A, also known
as progerin.
The farnesyl group locks progerin to the nuclear rim. While bound to the nuclear rim, progerin cannot
offer the necessary structural support to the nuclear envelope. As a consequence, the nuclear envelope is
misshapen. The structure of the nuclear envelope is essential for the proper manipulation of chromatin
during mitosis.
Figure 1. Mutant prelamin A post-translational processing
Needs
Review
Normal prelamin A post-translational modification consists of four steps. The processing begins with the
farnesylation of the cysteine of the CaaX box (cysteine and three aliphatic amino acids located at the
carboxyl terminus of prelamin A) by farnesyltransferase (FTase). Shortly thereafter, the –aaX portion of
the CaaX box is removed. Next, the product is methylated. Finally, the carboxyl terminal as well as the
modified farnesyl group is sliced off by the peptidase ZMPSTE24. Figure 2 illustrates normal prelamin A
post-translational processing. FTase inhibitors have been tested with animal models and shown to reverse
the malformation of the nuclear envelope caused by progerin.
Figure 2. Normal prelamin A post-translational processing
Needs
Review
11. Why is the malformation of the nuclear envelope
reversed in animal models when FTase
inhibitors are used?
A. FTase inhibitors catalyze the upstream
cleavage of the modified farnesyl group.
B. No progerin is made in the presence of FTase
inhibitors.
C. Normal prelamin A is created when FTase
inhibitors are present.
D. FTase inhibitors physically prevent progerin
from locking to the nuclear rim
12. One of the three amino acids found at the
carboxyl terminus of prelamin A could be:
A.
B.
C.
D.
tyrosine.
tryptophan.
phenylalanine.
alanine.
Needs
Review
13. What is the most likely reason for the production
of faulty prelamin A in individuals with
progeria?
A. The mutation introduces a new splice site,
resulting in loss of RNA from one of the
exons of prelamin A.
B. The point mutation causes a stop codon to
appear earlier in protein sequencing than is
normal.
C. The DNA splices and reforms at the lamin A
gene, removing part of the protein’s template
strand.
D. The protein that is sequenced from prelamin
A is less stable as a result of the mutation,
and it denatures.
14. Which of the following is most likely to result in
stunted growth and musculoskeletal
degeneration?
A. Structurally supported nuclear envelopes
B. Loss of the farnesyl group by prelamin A
C. Methylation of prelamin A during
posttranslational processing
D. The improper manipulation of chromatin
during mitosis
Needs
Review
15. What change occurs in DNA when a point
mutation changes a cytosine to a thymine?
A. One fewer hydrogen bond is formed between
base pairs.
B. A pyrimidine is changed into a purine.
C. An −OH group is added to deoxyribose.
D. The phosphate backbone is deformed due to
base pair mismatch
Lesson Review
INVESTIGATE means…
• Use prior knowledge and the passage, if necessary
• Predict what you can about the answer or decide to use elimination.
• Be flexible if your initial approach fails
Don’t be afraid to change your approach if:
• You find or remember new information
• The question is harder or easier than you first thought
• The question is taking you too long
MATCH means…
• Search the answer choices for a response that is synonymous to your
prediction
• Eliminate answer choices that diverge from your prediction or are factually
inaccurate
• Select an answer and move on
Reflect: What are 3 things from this lesson you recalled and what are 3
things you need to review more?
I knew:
I need to review:
1.
1.
2.
2.
3.
3.
The content in this lesson can be found in Biochemistry Review Chapter 1:
Amino Acids, Peptides, and Proteins , Biochemistry Review Chapter 2: Enzyme
Structure, Function, and Regulation , Biochemistry Review Chapter 6: DNA and
Biotechnology, and Biochemistry Review Chapter 7: RNA and the Genetic Code