Download Powerpoint for chapters 17-20 of Campbell Biology by Emily Diamond

Unit 4: Genes, Viruses,
and Biotech
Powerpoint for chapters 17-20 of Campbell
Biology by Emily Diamond
Chapter 17: Gene to
Protein
! 
Gene Expression
! 
the relationship between genes
! 
proposed by Archibald Garrod
! 
demonstrated by Beadle and Tatum
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
! 
Revisions to Beadle and Tatum s gene definition
! 
not all proteins are enzymes
! 
many genes code for RNA
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
! 
Basic Principles of Transcription and Translation
! 
Transcription
! 
Translation
! 
DNA needs a translator
! 
DNA is read in codons
! 
the universality of the code?
! 
template strand vs. the coding strand
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
! 
Eukaryotic mRNA modifications
! 
5 cap and polyadenylation
! 
splicing
! 
introns and exons
Chapter 17: Gene to
Protein
! 
Translation requires four things:
! 
mRNA
! 
amino acids
! 
ribosomes
! 
tRNA
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
! 
Translation has three steps
! 
initiation
! 
elongation
! 
termination
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
Chapter 17: Gene to
Protein
! 
the Polypeptide has been complete. we re done!
! 
WRONG!
! 
Proteins must be folded and can be posttranslationally modified Chapter 17: Gene to
Protein
! 
Polypeptides can be sent to specific locations
mid-translation
Chapter 17: Gene to
Protein
! 
Nucleotide mutations can affect polypeptides
! 
point mutations
! 
nucleotide pair substitution
! 
! 
missense vs. nonsense
nucleotide pair insertion or deletion
Chapter 17: Gene to
Protein
! 
Let s Review
Chapter 18: Gene
Expression Regulation
! 
Bacterial Gene Expression is often Regulated
through Operons
! 
Operons - consist of an operator, promoter,
and an entire stretch of DNA with more than
one gene on it
! 
Two types of operons: repressible and inducible
! 
We will look at two examples: the Trp Operon
and the Lac Operon
Chapter 18: Gene
Expression Regulation
! 
The Trp Operon
Chapter 18: Gene
Expression Regulation
! 
The Lac Operon
Chapter 18: Gene
Expression Regulation
! 
Eukaryotic Gene Expression Regulation can occur
at many steps.
! 
why can t this happen in bacteria?
Chapter 18: Gene
Expression Regulation
! 
Regulation of Chromatin Structure
! 
location of promoter relative to nucleosomes
! 
location of promoter relative to scaffolding and attachment to
lamina
! 
chemical modifications
Chapter 18: Gene
Expression Regulation
! 
Regulation of Transcription Initiation
Chapter 18: Gene
Expression Regulation
! 
RNA Splicing
! 
mRNA Degradation
! 
Translation initiation
Chapter 18: Gene
Expression Regulation
! 
Protein Processing and Degradation
Chapter 18: Gene
Expression Regulation
! 
Cancer can result as a breakdown of any of these
control steps
! 
oncogenes and proto-oncogenes
! 
tumor-supressor genes
! 
specific examples: ras, p53
! 
multistep model
! 
inherited predisposition and other factors
Chapter 19: Viruses
! 
Structure of Viruses: nucleic acid enclosed in a
protein coat, sometimes surrounded by an
envelope
! 
SOME VIRUSES INFECT BACTERIA:
PHAGES
some viruses have envelopes
Chapter 19: Viruses
! 
Viruses can only reproduce inside a host
Chapter 19: Viruses
! 
Bacteriophages can replicate two different ways
Chapter 19: Viruses
! 
! 
How do bacteria defend themselves?
! 
bacteria can often identify the virus as foreign
! 
lysogeny
How can we fight viruses
! 
the extent of the damage a virus can cause depends on a
tissues ability to regenerate. example: common cold vs
polio
! 
medicine
Chapter 19: Viruses
! 
Emergent Viruses ! 
mutations of current viruses
! 
dissemination form a small isolated population
(AIDS)
! 
spread of existing viruses from other animals Chapter 19: Viruses
! 
! 
Viral Diseases in Plants
! 
horizontal vs. vertical transfer
! 
viroids
Prions
! 
huge incubation periods
! 
virtually indestructible Chapter 20: Biotech
! 
Terms
! 
recombinant DNA
! 
biotechnology
! 
genetic engineering
Chapter 20: Biotech
! 
DNA Cloning
! 
most common approach uses bacteria (E. coli)
! 
because bacteria have plasmids
! 
basic idea
Chapter 20: Biotech
! 
How Gene Cloning happens: restriction enzymes
! 
very specific
! 
a specific example:
Chapter 20: Biotech
! 
Polymerase Chain Reaction (PCR)
! 
A 3 step cycle
! 
heating to denature and separate
! 
cooling to anneal
! 
extension of DNA primers with a heat-stable
DNA polymerase
Chapter 20: Biotech
! 
20.2 will be covered in lab.
! 
20.3 will be covered by your reading!
Chapter 20: Biotech
! 
Practical Applications
! 
! 
Medical Applications
! 
Disease Treatment and Diagnosis
! 
Gene Therapy ! 
Pharmaceutical Products
Forensic Applications Chapter 20: Biotech
! 
Practical Applications
! 
Environmental Applications
Credits and Copyright
! 
Information taken from Biology, 9th edition by
Campbell, Reece, et al..
! 
! 
Compiled and formatted for AP Biology by Emily
Diamond
All images Copyright 2005 Pearson Education,
Inc., publishing as Benjamin Cummings