Download Ch. 16_17_18 Objectives

Chapter 16
The Molecular Basis of Inheritance
Teaching Objectives
DNA Replication and Repair
1. Describe the process of DNA replication, including the role of the origins of replication
and replication forks.
2. Explain the role of DNA polymerases in replication.
3. Explain what energy source drives the polymerization of DNA.
4. Define antiparallel and explain why continuous synthesis of both DNA strands is not
possible.
5. Distinguish between the leading strand and the lagging strand.
6. Explain how the lagging strand is synthesized even though DNA polymerase can add
nucleotides only to the 3’ end. Describe the significance of Okazaki fragments.
7. Explain the roles of DNA ligase, primer, primase, helicase, topoisomerase, and singlestrand binding proteins.
8. Explain the roles of DNA polymerase, mismatch repair enzymes, and nuclease in DNA
proofreading and repair.
9. Describe the structure and function of telomeres.
10. Explain the possible significance of telomerase in germ cells and cancerous cells.
*Key to remember: DNA Polymerase READS DNA in the 3’  5’ direction, but BUILDS in the 5’
 3’ direction
Key Terms
DNA ligase
double helix
lagging strand
mismatch repair
nucleotide excision repair
origin of replication
primase
replication fork
single-strand binding protein
telomere
transformation
DNA polymerase
helicase
leading strand
nuclease
Okazaki fragment
phage
primer
semiconservative model
telomerase
topoisomerase
Chapter 17
The Connection Between Genes and Proteins
1.
2.
3.
4.
5.
From Gene to Protein
* = Not covered in class
Explain how RNA differs from DNA.
Briefly explain the Central Dogma.
Distinguish between transcription and translation.
Compare where transcription and translation occur in prokaryotes and in eukaryotes.
Define codon and explain the relationship between the linear sequence of codons on mRNA
and the linear sequence of amino acids in a polypeptide.
6. Explain why polypeptides begin with methionine when they are synthesized.
7. Explain what it means to say that the genetic code is redundant and unambiguous. *
8. Explain the significance of the reading frame during translation.
The Synthesis and Processing of RNA
9. Explain how RNA polymerase recognizes where transcription should begin. Describe the
promoter, the terminator, and the transcription unit.
10. Explain the general process of transcription, including the three major steps of initiation,
elongation, and termination.
11. Explain how RNA is modified after transcription in eukaryotic cells.
12. Describe the functional and evolutionary significance of introns.
The Synthesis of Protein
13. Describe the structure and functions of tRNA.
14. Explain the significance of wobble. *
15. Describe the process of translation (including initiation, elongation, and termination) and explain
which enzymes, protein factors, and energy sources are needed for each stage.
16. Describe the significance of polyribosomes. *
17. Explain what determines the primary structure of a protein and describe how a polypeptide must
be modified before it becomes fully functional. *
18. Describe what determines whether a ribosome will be free in the cytosol or attached to the rough
endoplasmic reticulum. *
19. Compare protein synthesis in prokaryotes and in eukaryotes.
20. Define point mutations. Distinguish between base-pair substitutions and base-pair insertions. Give
examples of each and note the significance of such changes.
21. Describe several examples of mutagens and explain how they cause mutations.
Key Terms
5’ cap
base-pair substitution
exon
intron
mutagen
point mutation
primary transcript
ribosomal RNA (rRNA)
RNA processing
signal-recognition particle (SRP)
template strand
transcription factor
transfer RNA (tRNA)
wobble
alternative RNA splicing
codon
frameshift mutation
messenger RNA (mRNA)
mutation
poly-A tail
promoter
ribosome
RNA splicing
spliceosome
terminator
transcription initiation complex
translation
anticodon
deletion
insertion
missense mutation
nonsense mutation
polyribosome (polysome)
reading frame
RNA polymerase
signal peptide
TATA box
transcription
transcription unit
triplet code
Chapter 18
1. Explain the adaptive advantage of genes grouped into an operon.
2. Using the trp operon as an example, explain the concept of an operon and the function of the
operator, repressor, and corepressor.
3. Distinguish between structural and regulatory genes.
4. Describe how the lac operon functions and explain the role of the inducer, allolactose.
5. Explain how repressible and inducible enzymes differ and how those differences reflect
differences in the pathways they control.
6. Distinguish between positive and negative control and give examples of each from the lac
operon.
7. Explain how cyclic AMP and catabolite activator protein are affected by glucose concentration.
8. Which operons are used for catabolic vs. anabolic process?