activators Correct Answers bind to DNA enhancer regions
adenylyl cyclase Correct Answers converts ATP to cAMP
allosteric regulation Correct Answers small molecule binds to
large protein and causes it to changes its shape and activity
arabinose operon Correct Answers another metabolic operon
under positive and negative control
conditions that lac structural genes expressed most efficiently
Correct Answers no glucose, high lactose
Define "operon" Correct Answers set of operator and promoter
sites and the structural genes they control
-in presence of glucose, lac operon not being stimulated
-transcription
Define distal and proximal; explain the role of enhancers and
promotor proximal elements in tissue-specific and coordinated
gene expression Correct Answers -proximal: near promoter
-distal: away from promoter
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Describe a typical replication cycle of an animal virus and
explain why viruses typically replicate and cause disease in only
certain species and replicate in only certain cell types Correct
Answers -capsid interact with host receptor (1st step)
, -lipid bilayer of virus fuses with membrane delivers nucleic acid
to cytosol
Describe characteristics common to all viruses & common
variations in structure and genome Correct Answers -some have
single molecule for genome, others segmented chromosomes
(influenza), animals can be infected with multiple different
strains simultaneously creating new novel viruses
-contain genetic material (either DNA or RNA) surrounded by
capsid (protein shell), some have membranous envelope that
contains glycoproteins
-enveloped viruses bud from host cell, retrovirus contains RNA,
capsid enters host cell if virus is enveloped, HIV contains
reverse transcriptase
-viral genome: "bad news", instructions for producing new virus
particles and for damaging effects to host cells and organisms
-viruses diverse: organized based on form of nucleic acid they
have and how they generate viral mRNA
Describe common mechanisms of viral pathogenesis Correct
Answers Pathogenesis is the process by which an infection
leads to disease. Pathogenic mechanisms of viral disease include
(1) implantation of virus at the portal of entry, (2) local
replication, (3) spread to target organs (disease sites), and (4)
spread to sites of shedding of virus into the environment.
Describe how replica plating can be used to identify certain lac
operon mutants Correct Answers
Describe the general roles and timing of our defenses against
viruses, including interferons, antibodies and cytotoxic (killer) T