PBS Unit 4 Study Guide
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Name_____________________
KNOW ALL KEY TERMS
- Use the definitions in the curriculum, crossword puzzles and online
quizlet to study these.
Activity 4.1.1: What Are Sickle Cells?
1. Describe the hemoglobin protein.
It is the primary component of red blood cells.
Fills the interior of the red blood cell and oxygen molecules bind to it.
It is composed of four sub-units. (two alpha-globin chains and two beta-globin chains)
2. Describe the difference between normal red blood cells and sickle cells.
Beta-hemoglobin S differs from normal beta-hemoglobin A by a single amino acid.
3. Draw a picture of a sickle cell.
Activity 4.1.2: What Are the Clinical Symptoms and Complications?
4. List one example for each of the following clinical aspects of sickle cell anemia:
D Dizziness, shortness of breath,headaches, jaundice, swollen hands and feet
a. symptoms - ____________________________________________________
D organ damage, blindness, gallstones, infections,stroke
b. complications - _________________________________________________
D blood transfusions, pain medication, Hydroxyurea, antibiotics
c. treatment - ____________________________________________________
D live to approx. age 50, cause of death usually due to organ failure and infection
d. prognosis - ____________________________________________________
5. What is the difference between someone having the sickle cell trait and having
sickle cell anemia?
Sickle disease= inherit two alleles for the sickle hemoglobin
Sickle trait = inherit one allele for sickle hemoglobin and one allele for normal hemoglobin
Activity 4.1.3: What Is the World Distribution of Sickle Cell Disease?
6. Name the disease associated with the concentration of sickle cell in certain areas
malaria
of the world: ______________________________
7. What areas of the world have the highest occurrence of sickle cell anemia?
Africa (especially Nigeria)
Activity 4.2.1: What Are Chromosomes?
8. How many chromosomes are in a normal cell? 46
Activity 4.2.2: The Story of HeLa Cells
9. Describe Henrietta Lack’s story.
Activity 4.2.3: The Doctor’s Point of View
10. In your opinion, was Dr. Gey’s use of Henrietta Lacks cells unethical? Support your
response with evidence from the two articles dealing with HeLa cells you read.
Activity 4.2.4: How Does Sickle Cell Pass through Families?
Activity 4.2.5: What Is a Family’s Pedigree?
Activity 4.2.6: What Is the Probability?
Review the pedigree and answer the following questions:
II.
I.
II.
III.
IV.
11. What is the relationship between generation III individual 4 and generation IV
individual 4? generation III individual 4 is the uncle of generation IV individual 4
12. If “H” = normal hemoglobin and “h” = sickle cell hemoglobin, what is the genotype of
generation IV individual 8? hh
13. How many individuals in generation II have sickle cell trait? 4
14. If generation IV individual 1 married someone without sickle cell disease or sickle
cell trait, what is the probability that their child would have sickle cell disease? 0%
Activity 4.3.1: How Do Chromosomes Carry Information?
Activity 4.3.2: What Is The Structure of DNA?
15. Label the diagram showing the relationship between the following terms: nucleotide,
gene, histone protein, DNA Double Helix, nucleosome, chromosome, gene.
nucleotide
ch
chromosome
G
gene
nucleosome
DNA Double helix
Histone protein
16. Using simple shapes, draw and label all parts of a nucleotide. See figure below.
17. Name all four bases of DNA – which bases are structurally similar to one
another? Which bases pair with each other? Which base is NOT present in RNA?
See figure below.
18. Does every cell in an organism have the same DNA? How do you know?
Yes, all cells are derived from the zygote
Activity 4.3.3: How is DNA Isolated From Cells?
19. How do scientists isolate DNA in order to study it?
Extract the DNA using lysis buffer and ethanol (Think about the lab we did.)
Activity 4.3.4: How Much DNA Is in a Human Cell?
Use the following information to complete the calculations.
Length of one nucleotide pair in a DNA helix: 3.4 angstroms
Estimated total number of nucleotide pairs in a human cell: 6 x 109
Number of amino acids in the β - hemoglobin chain: 146
1 angstrom equals 0.0000000001 meters.
1 micrometer equals 0.000001 meters.
20. How many DNA nucleotides code for one amino acid? _____3__________________
21. How many DNA nucleotides code for the β - hemoglobin chain? 3x146=438
22. What is the length of the DNA nucleotides in angstroms that code for the
β - hemoglobin chain? 438 x 3.4 angstroms = 1489.2 angstroms
23. What is the length of the DNA nucleotides in meters that code for the
β - hemoglobin chain? 1.4892 x 10-7 m
Activity 4.4.1: What is the DNA Code?
24. What is a gene?
A discreet unit of hereditary information
25. What is the DNA code?
Contains the code or instructions for how to make specific proteins which then
determine the organism’s traits.
26. What is the connection between genes and proteins?
The specific instructions for a protein are on sections of the chromosome called genes.
27. How are proteins produced in a cell?
Transcription
translation
protein synthesis
28. How does the sequence of nucleotides in DNA determine the sequence of amino acids
in a protein?
Each triplet codon codes for a specific amino acid.
29. Describe in 4-5 sentences how a protein is made from start to finish. Use the
terms: ribosome, nucleus, RNA, DNA, transcription, cytoplasm, amino acid,
translation, codon
see 4.4.1
30. Complete the steps using the following DNA strand and Codon chart
DNA
TACGCAAATGGT
mRNA
AUGCGUUUACCA
_________________________________________
tRNA
UACGCAAAUGGU
_________________________________________
MET-ARG-LEU-PRO
amino acid ________________________________________
Activity 4.4.2: What Determines the Shape of a Protein?
Project 4.4.4: How Are Designer Proteins Made?
31. What determines the shape of a protein (hint: there are SEVERAL factors)?
Amino acid sequence primarily determines a proteins shape, but secondary (alpha helix and beta sheet)
and tertiary structures (Hydrogen bonding, other chemical bonding between structures) adds to it.
32. If the DNA code is changed, does the shape of a protein change?
Yes
33. Draw a general amino acid. Which atoms in all of the amino acids form the “amino”
portion of the molecule? Which atoms form the “acid” portion of the molecule?
34. Explain the difference between hydrophobic and hydrophilic.
Hydrophobic = water-fearing
Hydrophilic = water-loving
35. Review the amino acid chain. The hydrophobic amino acids are labeled “h” and the
hydrophilic amino acids are labeled “H”.
H-H-H-H-h-h-h-h-h-h-H-H-H-H-H-h-h-h-h-h-H-H-H-H-H-h-h-h-h-h
a. Draw the resulting folded amino acid chain if placed in water.
36. If the DNA code is changed, does the shape of a protein change? Explain.
Different sequences of amino acids are built so there will be different hydrophobic and
hydrophilic regions of the protein which will determine the shape.
37. Can changing just one nucleotide in a gene change the shape of a protein? Explain.
Yes. One nucleotide will changes the codon and therefore changes the amino acid in
the chain which changes the protein that is made.
38. How would a scientist design proteins that have specific characteristics?
Combine specific amino acid sequences
Activity 4.5.1: What is Karyotyping?
39. What is the purpose of a Karyotype?
Analyze chromosomes to see if a person has an normal or abnormal number of
chromosomes.
40. How can doctors detect if a patient has an abnormal number of chromosomes? Give
an example of a syndrome you studied in class – how many chromosomes would a
person with this syndrome have? Look at the karyotype to see if a person has more or
less than 46 chromosomes.
Down’s Syndrome – Extra on the 21
Trisomy 13 - Extra on the 13
Klinefelter’s - XXY
41. What happens if someone has more or fewer than 46 chromosomes?
If a person has fewer chromosomes it is usually lethal.
If a person has more they will have a syndrome.
Activity 4.5.2: Does Changing Just One Nucleotide Make a Big Difference?
42. How does changing a nucleotide in the DNA code for the ß-globin protein change the
characteristics of the entire hemoglobin protein?
Due to a change in the nucleotide a completely different protein is coded for. The normal
protein has glutamic acid which is hydrophilic. The mutated protein has valine which is
hydrophobic. Therefore the shape of the protein changes.
43. Explain the difference between normal hemoglobin DNA and sickle cell disease DNA.
44. Explain the difference between normal hemoglobin protein and sickle cell disease
protein.
Beta-hemoglobin S differs from normal beta-hemoglobin A by a single amino acid. This single
substitution makes the hemoglobin more prone to polymerize when oxygen is not bound, thus
distorting the shape of the red blood cell into a half-moon or sickle shape as opposed to the normal
concave round shape.