Download Unit 1 – Biochem 1. Consumers ingest large amounts of the

Unit 1 – Biochem
1. Consumers ingest large amounts of the carbohydrate polymers starch and cellulose, but only the
glycogen polymer is found in significant amounts in the body, mainly in the liver and the muscle cells.
Explain in one paragraph why this is observed.
2. Mysterious disease “X” is found to be caused by a misfolded protein. The misfolding is traced back to a
mutation that results in the substitution of a polar amino acid for a nonpolar amino acid. Explain in one
paragraph what has occurred.
3. Phosphofructokinase is an enzyme used during the pathway of cellular respiration, which ultimately
breaks down glucose to transfer the energy to the ATP molecule. It acts on the substrate fructose 6phosphate. In cells that have abundant ATP, this enzyme’s reaction rate is very low. It’s found that the
substrate is unable to bind to the enzyme. Explain in one paragraph what is occurring and WHY.
LAB Review
An experiment was conducted to measure the reaction rate of the human salivary enzyme αamylase. Ten mL of a concentrated starch solution and 1.0 mL of α-amylase solution were
placed in a test tube. The test tube was inverted several times to mix the solution and then
incubated at 25°C. The amount of product (maltose) present was measured every 10 minutes
for an hour. The results are given in the table below.
Time (minutes)
Maltose Concentration (M)
0
0
10
5.1
20
8.6
30
10.4
40
11.1
50
11.2
60
11.5
(a) Graph the data and calculate the rate of the reaction for the time period 0 to 30 minutes.
(b) Explain why a change in the reaction rate was observed after 30 minutes.
(c) Draw and label another line on the graph to predict the results if the concentration of
amylase was doubled. Explain your predicted results.
(d) Identify TWO environmental factors that can change the rate of an enzyme-mediated
reaction. Discuss how each of those two factors would affect the reaction rate of an enzyme.
1. If the pH of a solution is increased from pH 5 to pH 7, it means that the hydrogen ion
concentration has changed by a factor of _________ (be careful of your signs). SHOW
YOUR WORK.
2. If a DNA sample were composed of 10% thymine, what would be the percentage of
guanine? SHOW YOUR WORK.
3. An enzyme reaction has been observed to accumulate product at a rate of 10.7 grams per
minute. After adding substance A, the reaction occurs at a rate of 15.6 grams per minute.
After adding substance B, the reaction occurs at a rate of 8.7 grams per minute. What is
the standard deviation of these enzyme reaction rates? SHOW YOUR WORK.
Xi = individual data point
=
average
∑ = Sum
n = total number of sample data points
Unit 2 – Cells
1. The permeability of Red Blood Cells (RBC) varies depending on environmental conditions. Explain in
one paragraph how this occurs.
2. The transport of water is essential to plant survival. The soil surrounding the roots is naturally higher in
solutes than the roots, but plants are able to pump ions into the roots. Explain in one paragraph what
has occurred and how this will affect the movement of water.
3.Respiration concludes with a pH gradient being created by
using electron energy to pump H+ ions out from the matrix and into
the intermembrane space. The only location permeable to H+ ions
is the ATP synthase enzyme, which utilizes the diffusion of H+ ions
down their gradient to catalyze the creation of ATP from ADP and
P. Explain in one paragraph how membrane structure
determines function.
LAB Review
Beta cells of the pancreas secrete “mature insulin”, a protein that is 35 amino acids fewer than
the original polypeptide synthesized at the ER. This protein is made in response to rising levels
of sugar in the blood and binds to receptors on liver and muscle cells to signal for the target cells
to remove sugar from the blood to be stored as glycogen. Explain how the endomembrane
system contributes to ensure that the insulin is effective.
1. A scientist is preparing an
environment to grow cells. A 0.2M
solution is created and maintained at
solute potential? SHOW YOUR WORK.
saline (NaCl)
22˚C. What is the
2. When the cells are placed in this environment, the cells gain water. Before being placed in
the solution, the water potential of the cells had to be less than what value? SHOW YOUR
WORK.
3. The scientist tests three different types of cells in the environment. Cells “A” experience a
20% increase in mass. Cells “B” experience a 2% increase in mass. Cells “C” experience a
5% decrease in mass. What is the standard deviation of the change in mass in the three
cell types? SHOW YOUR WORK.
Xi = individual data point
= average
∑ = Sum
n = total number of sample data points
Unit 3 – Cellular Energy
1. In the heart, glycolysis may be a preferential source of adenosine triphosphate (ATP) for cellular
membrane functions, such as activation of gated channels. Explain in one paragraph why this might
occur.
2. A cell has an abundance of 3-C molecules. Explain in one paragraph how this might have
occurred and what the cell could do with the three carbon compounds.
3. DCMU is an herbicide that blocks electron flow from Photosystem II to the rest of the light-dependent
reactions. Explain in one paragraph how this will affect photosynthesis.
LAB Review
Organization of structures is important to the functioning of the organism. Identify how both
leaf and chloroplast structures are important to photosynthesis. Evaluate how changes in
structure could be either beneficial or harmful to the process.
1. The intermembrane space and the matrix are found to have a 1000 times difference in the
concentration of hydrogen ions. The pH of the matrix is found to be 8. What is the pH of
the intermembrane space? SHOW YOUR WORK.
2. A cell is found to have a chain of starch with 72 carbons. If each NADH makes 2.5 ATP
and each FADH2 makes 1.5 ATP, how many total ATP will be made when the starch
molecule is completely metabolized? SHOW YOUR WORK.
3. The scientist tests three photosynthetic cells in differing environments. Cells “A”
experience a 20% increase in ATP production. Cells “B” experience a 2% decrease in ATP
production. Cells “C” experience a 5% increase in ATP production.
What is the standard deviation of the change in mass in the three
cell types? SHOW YOUR WORK.
Xi = individual data point
=
average
∑ = Sum
n = total number of sample data points
Unit 4 – Cell Reproduction
1. A variety of cells are found to have entered G0 at different points in the cell cycle. Describe G0 and give
three examples why a cell might be in G0.
2. Thomas Hunt Morgan and his lab used
crossing over rates to create the first gene
maps. Morgan’s data showed higher frequency
of combinations of long aristae with brown eyes
than long aristae with black bodies. Use the
principles of crossing over to explain why these
results allowed Morgan to create an estimated
gene map.
3. Describe how the cell can signal whether or
not to pass the spindle checkpoint. Describe
the effect on both mitosis AND meiosis if the
signal is incorrect.
LAB Review
Sexual reproduction requires that half of the chromosomes in a zygote come from one parent
and the other half from the second parent.
(a) Describe the process by which a germ cell’s complement of chromosomes is halved in the
formation of the gametes.
(b) Choose one organism of group of organisms that reproduce asexually. Describe the
mode of asexual reproduction in that organism and explain the advantages to the
organism of asexual reproduction.
(c) Choose one organism of group of organisms that reproduce sexually. Describe the mode
of asexual reproduction used in that organism and explain the advantages to the
organism of sexual reproduction.
4. A cuboidal epithelium cell that lines the kidney has sides of equal length that are 150
micrometers in length. Calculate the surface area of this cell. SHOW YOUR WORK.
5. A cell is found to have a surface area to volume ratio of 3:2. The volume of the cell is 2.3
cubic micrometers. What is the surface area of the cell? SHOW YOUR WORK.
6. The scientist tests three tumor cultures in differing environments. Cells “A” experience a
15% increased rate of cell division. Cells “B” experience a 10% decreased rate of cell
division. Cells “C” experience a 5% decreased rate of cell division.
What is the standard deviation of the changes in division rate of the
three cell types? SHOW YOUR WORK.
Xi = individual data point
=
average
∑ = Sum
n = total number of sample data points
Unit 5 – Genetics
1. Explain how Klinefelter syndrome is an example of an error in one of Mendel’s Laws.
2. A woman went on a TV show to get help figuring out her baby’s father. The baby is blood type O, and
the mother is blood type B. The two possible fathers are blood type A and blood type O. Explain if you can
identify whom the father is. Identify why the use of science on these shows increase the perception of
drama.
3. True breeding bronze-eyed, stunted-winged male fruit flies were crossed with true-breeding red-eyed,
normal-winged females. All the F1 offspring had bronze eyes and stunted wings. The F1 flies were crossed
with true-breeding red-eyed, normal-winged flies and the results are shown in the table below. What
conclusions can you draw from this data? Explain how the data supports your conclusions.
Phenotype
Male
Female
Bronze eyes, stunted wings
2,360
2,220
Bronze eyes, normal wings
220
300
Red eyes, stunted wings
260
220
2,240
2,180
Red eyes, normal wings
LAB Review
Given the above pedigree:
a) Identify all possible patterns of inheritance and justify your answers.
b) Identify all the possible genotypes for the parents in the box.
c) Select one possible pattern of inheritance and perform a Chi-Square analysis on the F1 generation to
determine if the observed data supports your expected ratio. Use the p-value of 0.05.
1. A purebred normal-winged female fly with red eyes is crossed with a vestigial-winged male
fly with white eyes. What percentage of the offspring are expected to be vestigial-winged
males with white eyes? SHOW YOUR WORK.
Phenotype
# of flies
observed
2. A purebred normal-winged female fly with red eyes is
crossed with a vestigial-winged male with white eyes.
They have 370 offspring. How many of the flies would
be expected to have normal wings? SHOW YOUR
WORK.
3. The flies from the above crosses mate and produce an
F2 generation. The chart below shows the offspring.
Calculate the Chi-square value for this cross. SHOW
YOUR WORK.
Female, normal-winged, red eyes
137
Female, normal-winged, white eyes
0
Female, vestigial, red eyes
48
Female, vestigial, white eyes
0
Male, normal-winged, red eyes
69
Male, normal-winged, white eyes
67
Male, vestigial, red eyes
24
Male, vestigial, white eyes
25
Unit 6 – DNA and Protein
1. A woman went on a TV show to get help figuring out her baby’s father. The baby is blood type O, and
the mother is blood type B. The two possible fathers are blood type A and blood type O. Explain if you can
identify whom the father is. Identify why the use of science on these shows increase the perception of
drama.
2. A cell that has been exposed to radiation is found to no longer produce ligase, even though the mutation
did not occur in the ligase gene. Identify TWO other explanations for why ligase is not being
produced. Describe the impact of not having ligase.
3. Insulin production occurs in the Beta cells of the pancreas and then insulin signals to muscle
and adipose cells to increase their uptake of glucose from the blood. If transcription has already
occurred, identify TWO possible ways the cell can decrease the amount of insulin
produced. Contrast the TWO gene regulation examples you chose with the use of a
molecule that would compete with insulin at the insulin receptors.
LAB Review
1. The insulin protein is 51 amino acids long. If mRNA is made at a rate of 50 bases/second and amino
acids are joined at a rate of 20 amino acids/second, how long does it take Beta cells to make insulin?
SHOW YOUR WORK and complete the grid.
Unit 7 – Evolution
Some mutants of Staphylococcus aureus have an enzyme that cleaves antibiotics (such as
methicillin), thereby rendering the antibiotic ineffective. As the CDC collects data on antibioticresistant infections, they also track the number of staph infections that are considered “wildtype.” The scientific community is considering if methicillin-resistant Staphylococcus aureus
(MRSA) should be considered a separate species.
1) Explain how MRSA differs phenotypically from the wild-type.
2) Explain what causes this phenotypical difference.
3) A patient’s culture comes back from the lab with a mixture of MRSA and the wild-type.
Explain what will happen if this patient is given methicillin.
4) List the five conditions needed for a population to be at Hardy-Weinberg equilibrium.
Describe how each condition could be seen in this population.
5) Describe what data and evidence would be used to determine if MRSA is a different species.
A large population of laboratory animals has been allowed to breed randomly for a number of
generations. After several generations, 25% of the animals display a recessive trait (aa), the
same percentage as at the beginning of the breeding program. The rest of the animals show the
dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants.
6)
What is the
estimated frequency
of the allele A in the
gene pool?
7)
What proportion of
the population is
probably
heterozygous (Aa)
for this trait?
Show your work.
Show your work.
8)
In another
population, the
frequency of the a
allele is at 0.1. What
is the percentage of
the population that is
heterozygous for this
allele?
Show your work.
9)
In a third population,
the frequency of the
a allele is 0.2. What
is the percentage of
the population that is
heterozygous for this
allele?
Show your work.
After the formation of a new island, the island is colonized by a flock of traveling seagulls. A rare
mutation can occur that causes the seagulls to be missing the webbing between the bones of
their feet. Out of the 10 colonizing seagulls, none are missing the webbing. In one mated pair,
25% of their F1 generation are missing the webbing. The rest of the mated pairs have 100%
normal offspring.
10) What is the frequency of the 11)
recessive allele in the
population of the founding
seagulls? Show your work.
After 3 generations, the
frequency of the dominant
allele is found to be 0.85.
Determine the Chi Square
value for the differences found
between the frequencies of
the two alleles after 3
generations.
Show your work.
12)
After 10 generations, the
frequency of the recessive
allele is found to have
doubled. Given a population of
500 birds, how many birds
would be expected to be
missing the webbing?
Show your work.
13) Sheathbills are Antarctic birds without webbing between their feet. Describe if this is an
example of homology or analogy and explain why.
Unit 8 – Classification
1. Archaebacteria such as Halarchaeum acidiphilum Strain MH1-52-1(T) are able to grow at pHs
between 4.0-6.0. The differences in the hydrogen ion concentration is… SHOW YOUR
WORK.
2. A collection of leaf litter containing fungal species is shown to decrease in weight from 35
grams to 21 grams in a 7 day period. What is the daily rate of decomposition? SHOW YOUR
WORK.
3. A taxonomist is examining samples from organisms B, C, and D. The anatomical structures
all appear similar to organism A. Within organism A’s specie, there is usually a 95% similarity
of nucleotide sequences. After examining the nucleotide differences, the taxonomist uses the
Chi-Square formula to determine if there is any significant difference between the expected
number of nucleotide differences and the observed. SHOW YOUR WORK.
Organism
LAB Review
# of nucleotide similarities with
reference organism “A”
Organism B
4,340,000 out of 4,600,000
Organism C
4,360,000 out of 4,600,000
Organism D
4,355,000 out of 4,600,000
1) Cytochrome b is one of the embedded proteins in the ETC of the mitochondria. When
examining the Plasmodium genus, researchers examined Mitochondrial DNA.
Differences in mitochondrial DNA sequence for Cytochrome b gene
P. falciparum
P. reichenowi
P. gallincaeum
P. lophrae
P. mexicanum
P. falciparum
P. reichenowi
P. gallincaeum
P. lophurae
P. mexicanum
0
2
6
8
10
0
6
8
10
0
2
10
0
10
0
a) Explain why mitochondrial DNA would be examined.
b) Create a phylogenetic tree based on the data.
c) If P. lophurae and P. mexicanum were found to have identical “ATP synthase subunit a”
proteins, describe what would this mean about the phylogenetic tree.
2) IN ESSAY FORM: Organisms differ from one another and yet share common characteristics.
a. Select two kingdoms and briefly describe three characteristics used to distinguish between
members of one kingdom and members of the other.
b. Describe three characteristics (at least one molecular and one cellular) that members of
these two kingdoms share.
c. Propose an explanation for the existence of similarities and differences between the two
kingdoms.
Unit 9 – Microorganisms and Immune
HIV is found to exist in two main types – HIV-1 and HIV-2. HIV-1 contains groups M, N
and O. Each group contains several clades. Group M clade B is currently the most
prevalent in North America and Europe, while group M clade C is most prevalent
worldwide.
1) Would variation within the reverse transcriptase gene be expected? Why or why not?
2) HIV is found to mutate at a rate of 10-3 substitutions per reproductive cycle. The HIV genome
is 9,200 bases. Over 2 generations, how different would two viruses be expected to be?
Highly active anti-retroviral drugs have been found to delay onset of clinical disease.
However, inadequately treated or nonadherent persons is an increasing concern, as is
transmission of drug resistant strains (primary resistance).
3) Compare and contrast two possible anti-retroviral drug targets.
4) Choose one of your above anti-retroviral targets from #3 and explain how drug resistance
could develop.
Antibody 2G12 is found to bind to a carbohydrate found on the glycoprotein of HIV.
However, after several years of HIV infection, the antibody is only effective in 1% of
individuals.
5) Describe the normal pathway for antibody effectiveness.
6) Predict why the effectiveness of the antibody decreases over time.
LAB Review
Unit 10 – Animal Systems and Behavior
1. “Cells communicate with each other from a distance via chemical signaling.” Elaborate on how the
endocrine system uses molecular behavior to allow for specific signaling.
2. Thyroxine increases the body’s metabolic rate. Grave’s disease is also known as hyperthyroidism.
Predict the symptoms that would be seen in a patient with Grave’s disease.
3. Explain how the surface area of the small intestine relates to both digestion and absorption.
4. GABA is a neurotransmitter that binds to receptors and allows the flow of positively charged
potassium ions OUT of the neuron. Describe the effect on the polarization of the neuron and
predict if this would be an inhibitory or excitatory response. (Answer on the back)
5. Alcohol is known as a depressant. What effect would alcohol have on inhibitory
neurotransmitters and excitatory neurotransmitters?
6. The nerve gas sarin inhibits the enzyme acetycholinesterase, which is normally present in the
neuromuscular junction and required to break down acetycholine into inactive fragments. Based
on this information, what do you think are the likely effects of this nerve gas on muscle
function?
LAB Review
Unit 11 – Plants
Trichomes are small hairs found on the surface of leaves and stems. Hairs on plants are extremely
variable in their presence across species, location on plant organs, density (even within a species), and
therefore functionality. However, several basic functions or advantages of having surface hairs can be
listed. It is likely that in many cases, hairs interfere with the feeding of at least some small herbivores
and, depending upon stiffness and irritability to the "palate", large herbivores as well. Hairs on plants
growing in areas subject to frost keep the frost away from the living surface cells. In windy locations, hairs
break up the flow of air across the plant surface, reducing evaporation. Dense coatings of hairs reflect
solar radiation, protecting the more delicate tissues underneath in hot, dry, open habitats. And in locations
where much of the available moisture comes from cloud drip, hairs appear to enhance this process.
1) Predict whether the variation in trichomes is likely the result of divergent or convergent
evolution and explain why.
2) What evidence would you need to support your prediction?
3) In a population of plants, some have 10 trichomes per square cm and others have 5
trichomes per square cm. Which population would be more subject to herbivory rates? Why?
4) When a plant is wounded, the hormone jasmonate is released, which can have several effects
including the growth of more trichomes. The jasmonate pathway includes transcription
factors. Explain how jasmonate can help a plant respond to increased herbivory rates.
5) Trichomes are also found to decrease transpiration rates by slowing wind speed. Explain how
this provides an advantage for plants in windy environments.
LAB Review
1. A scientist is preparing a hydroponic
environment to grow plants in. A
(NaCl) solution is created and
What is the solute potential of the
YOUR WORK.
0.2M saline
maintained at 22˚C.
solution? SHOW
2. When the cells are placed in this environment, the cells gain water. Before being placed in
the solution, the water potential of the cells had to be less than what value? SHOW YOUR
WORK.
3. While measuring root growth, a plant is found to have 400 cells in the roots one day, 440
the next day and 484 cells on the third day. The scientist is expecting that after day 5’s
growth, differentiation will be seen in 5% of the cells. How many cells is the scientist
expecting to see be differentiated? SHOW YOUR WORK.
Unit 12 – Ecology
1. There are 2,000 mice living in a field. If 1,000 mice are born each month and 200 mice die
each month, what is the per capita growth rate of mice over a month?
2. As N approaches K for a certain population, what is predicted by the logistic equation?
3. In 2009, the US had a population of about 307 million people. If there were 14 births and 8
deaths per 1000 people, what was the country’s net population growth that year (ignoring
immigration and emigration)?
4. A hypothetical population has a carrying capacity of 1,500 individuals and rmax is 1.0.
a. Complete the following table if the population sizes were as shown
Current Population size
Expected change in population
1,600
1,750
2,000
b. What is happening to this population?
Why?