Biotechnology Semester Exam Review
Acids and Bases
1. Describe an acid and a base.
2. What is the pH scale?
3. How does a buffer work? (Think about the bromothymol blue in the electrophoresis chambers)
DNA Structure and Replication
1. What is a nucleotide and what are the 3 components?
2. The bases are attached to which numbered carbon of the deoxyribose?
3. The phosphates are attached to which numbered carbons on the deoxyribose?
4. In the molecule below, label the 5' end and the 3' end. What do the numbers 5 and 3 refer to? Label the sugar, phosphate, and 4 nitrogen bases.
5. What does it mean that the strands of the DNA molecule are antiparallel?
6. What is the difference between purines and pyrimidines? Which bases are examples of each type?
7. Name the two base pairs in the DNA molecule.
8. What term is used to describe the shape of the DNA molecule?
9. What makes the DNA molecule negatively charged?
10. Why is important that the inside of DNA is neutral and the outside of the molecule is charged?
11. List the steps in DNA replication.
12. What are Okazaki fragments and where do they form?
13. Give the functions of the following enzymes:
helicase:
primase:
DNA polymerase:
ligase:
14. Polymerase can only replicate DNA in which direction?
DNA Sequencing
1. Why are four test tubes used to sequence a particular section of DNA?
2. What is added to each of those four test tubes?
3. What occurs in each test tube?
4. What results in each test tube?
5. How is a gel set up after the reactions are run in each test tube?
6. How is a sequencing gel interpreted after electrophoresis?
7. What is the difference between a deoxynucleotide and a dideoxynucleotide?
Protein Synthesis
1. What is a codon, and what is its function?
2. Given the following DNA sequence, list the amino acids coded for by the sequence.
3' T A C A A A C G A C G C G T A T C A A T T 5'
mRNA code chart
3. What does the "met" amino acid signal?
4. List three types of DNA mutations and describe how they affect the protein
that is produced.
5. What kind of point mutation is the most potentially damaging mutation?
6. What enables a protein to perform its function?
7. List three differences between the structure of DNA and RNA.
8. DNA is always replicated and transcribed in what direction?
9. What is meant by the following terms: coding strand, noncoding strand, template
10. Which strand is transcribed (read) by mRNA?
11. What is the function of RNA polymerase?
12. What is an intron? an exon?
13. Describe the structure of tRNA, then give its function.
14. State the "central dogma" of genetics.
______
15. List the steps in protein synthesis.
Semester 1 Review
3. Diagram how you would perform a 1:3 serial dilution with 36mg/mL of amylase stock solution.
4. Graph the following data taken from a spec:
Tube # Absorbance value
Tube 1 1.6 au
Tube 2 .6 au
Tube 3 .2 au
Tube 4 .02 au
Using your graph you just created, What should be the absorbance of a 30mg/mL solution?
Restriction Enzymes
5. Define the following terms:
SNP
VNTR
STR
6. What is a restriction enzyme and what is its function?
7. What is meant by sticky ends? Blunt ends?
8. What are DNAases?
9. Look at the sequence of DNA that is attached to this review, cut it with ECOR1 and then cut the second sequence with HindIII.
ECOR1 GAATTC HindIII AAGCTT
CTTAAG TTCGAA
ECOR1 HindIII
DNA Fingerprinting and RFLP
1. Who discovered the theory behind DNA fingerprinting? What is a DNA profile?
2. Suppose a RFLP was done using two loci. Each locus has two possible alleles.
How many bands would be in the lane from a person who was heterozygous for both
loci?
Homozygous for one locus and heterozygous for the other locus?
Homozygous for both loci?
3. How can scientists obtain a 1/1,000,000 chance match with the general population
using VNTRs to determine the identify of a suspect in a crime? How is chance
frequency determined when multiple loci are investigated?
4. What are probes?
5. Why are probes used?
6. How are probes used to identify the location of a "gene" on a chromosome?
7. List the steps in the RFLP procedure (southern blotting).
Polymerase Chain Reaction
1. List the three stages in the PCR process. What happens in each stage?
2. What temperatures are required for each stage?
3. What substances are required for each stage?
4. What prevents DNA strands from reannealing in the hybridization stage?
5. What is TAQ polymerase and how is it different from other DNA polymerases?
6. Describe the PV92 locus on chromosome #16. What does it code for? How many
alleles does it have?
7. List how many bands would be present on a gel after PCR for the PV92 locus for persons who are homozygous and heterozygous.
8. What is primer and how is it important to the PCR process?
9. A DNA sequence for amplification is shown below. What will be the length of the target PCR product?
3' T T C G C C C A T A C G T T A 5'
5' A AG C G G G T A T G C A A T 3'
Primer A: 5' C G G G 3'
Primer B: 3' C G T T 5'
10. What happens during hybridization?
11. What happens during denaturation?
12. How do scientists control which segment of a chromosome is amplified?
13. What is a thermocycler? What does it do?