Download Reading Guide for Week 5

Reading Guide for Week 5 – Bio260
Colleen Sheridan
Stage 02 – Colonization and Infection
Now that our bacteria have transported in nutrients, broken them down through a series of catabolic reactions to
harvest energy, stored that energy in ATP, reducing power, and the proton motive force, and produced a
multitude of precursor metabolites, its time to use that energy and those precursor metabolites in anabolic
reactions to build new cells. We’ve already seen how precursor metabolites are used to build subunits (amino
acids, nucleotides, fatty acids, glycerol, and monosaccharides). In this reading guide we’ll put those subunits
together to make macromolecules through the processes of DNA replication, transcription, and translation, and
put those macromolecules together to make cellular structures (for example: protein + phospholipids = cell
membrane). We’ll also learn about another type of microbe, the virus, and look at how it replicates itself by
taking over these macromolecular-generating processes inside our own eukaryotic cells.
In this week’s reading you will learn about:
1. DNA Replication, and the regulation of gene expression through transcription and translation
2. Different types of viruses, viral structure, and viral replication.
Essential question: As you are reading, keep asking yourself, “How is this helping me to understand how
bacterial cells undergo binary fission during colonization or infection?”
Chapter 7: The Blueprint of Life, from DNA to Protein (7.1 – 7.3, 7.5 – 7.6)
Some terms and structures to know:
1. Know the definition of the following terms: genome, gene, protein, genomics, DNA replication,
transcription, and translation.
2. What is meant by the terms genotype and phenotype? (Use glossary if needed)
3. What is a gene? What is the relationship between a gene and a protein?
4. Understand all the chemical components found in DNA. Be able to draw a representation of DNA as in
Figure 7.2
5. Know the characteristics of DNA and RNA.
In order to make a new bacterial cell, the cell has to make a duplicate copy of its DNA. How does it do
that?
6. Be able to explain DNA replication. What is meant by semi-conservative replication? Know the role of all
the enzymes involved in the process of DNA replication.
In order to make a new bacterial cell, the cell has to make a duplicate copy of its structural and
regulatory proteins. How does it do that?
7. Understand the process of transcription. What enzyme is key in the process? Where does it bind to DNA?
What forms of RNA can be made in transcription? What happens at each stage of transcription; initiation,
elongation, and termination?
8. Understand the process of translation. What happens at each stage: initiation, elongation, and termination?
9. Be able to replicate, transcribe, and translate a sample of DNA.
In order to make a new bacterial cell, the cell has to sense its environment and respond to changes in
order to keeping growing. How does it do that?
10. Understand the three ways in which enzyme expression is regulated. Know an example of each.
11. Understand how the DNA binding protein repressors and activators work.
13. Understand how the lactose operon works. What conditions are necessary to turn the operon “on”, what
conditions are necessary to turn it “off”? Understand what occurs in reference to the lactose operon to cells
growing in the presence of both glucose and lactose.
14. Understand how organisms respond to environmental conditions and alter gene expression through signal
transduction, two-component regulatory systems, and quorum sensing. How does natural selection play a
role in gene expression?
Essential question: As you are reading, ask yourself, “How is this helping me to understand how viruses
replicate during infection?”
Chapter 13: Viruses (13.1-13.2, 13.6-13.8)
What is a virus?
1. Are viruses considered living?
2. What is a bacteriophage?
3. What is a virion? Describe the chemical composition of a typical virus. (capsid coat, nucleic acid etc)
4. What is the difference between a naked virus and an enveloped virus?
5. Read through Table 13.1, pick 3 virus families and know the information in the table about them.
How do viruses replicate?
6. Explain the steps in the life cycle of T4 (lytic/virulent) bacteriophage. What is the host cell?
7. Explain the steps involved in the life cycle of lambda phage (temperate phage). What is the host cell?
8. What is a benefit of infection with a lysogenic phage? What change may occur with the bacterial cell?
9. What are the generalized steps of infection of an animal cell by a virus? How do the steps of infection of an
animal virus differ from infection with a bacteriophage?
10. Understand how single stranded DNA and RNA animal viruses replicate. What is meant by (+) ssRNA
versus (-) ssRNA?
11. What is unique to viruses in the family Retroviridae? What is an example of a virus in this family?
How do viruses interact with the host and how does that affect their growth?
12. Understand what is meant by acute and persistant viral infections and identify an example of each.
13. Understand the two different types of persistant infections and an example of each.
14. Understand how animal viruses may induce tumors. What type of virus most commonly induces tumors?
How do viruses induce tumors in animal cells?
15. Understand Figure 13.18 and the various effects that animal viruses have on infected cells.