Announcements
Quiz Today!
Labs 9-11, 13-14
Today’s
plan
Start chapter 8 -
Genetics
•Genome-all
the genetic information in a cell
•Chromosome-the
physical structure that carries the genes
•Genes-
sequences of base pairs that code for a protein
•Genotype-potential
of the cell not all genes expressed
•Phenotypes-observed
traits, expressed genes, proteins coded for
Genetics overview (flow) Figure 8.2
Genotype vs.
phenotype
Catalase
test result for E. coli when grown under aerobic conditions?
anaerobic?
Nucleotides
Nitrogen
base (purine or pyrimidine)
Back to Chapter 2!
pp.47-49
RNA - AGCU
Nitrogen base (purine
or pyrimidine)
5 C sugar (ribose or
deoxyribose)
PO4 group
Hydrogen Bonding of
the bases
DNA
Double Helix
Double Stranded
•RNA is single stranded, uracil
replaces thymine
•Messenger RNA -(mRNA) “writes” or
transcribes the DNA codes
•Transfer RNA-(tRNA)- translates the
mRNA into proteins
•Ribosomal-RNA (rRNA) part of the
structure of ribosomes where protein synthesis
occurs
•Details Later!
•Sequence of base pairs that code
for a protein
•Average 1000 base pairs per gene
•Most sequences are nonsense or
code for nothing
Oswald Avery, Colin MacLeod and Maclyn
McCarty
Macleod and McCarty
Helped Avery purify the
“transforming” factor.
DNA
was isolated, a compound ubiquitous
to living organisms.
Not
sure how it works though.
Double
Helix structure of DNA
Rosalind Franklin
“DNA
image”
Watson & Crick
“Structure”
DNA
Polymer of
nucleotides: adenine, thymine,
cytosine, guanine
•Nucleotide is a
monomer
•Backbone is
deoxyribose-phosphate
•Notice number of H
bonds between bases
Fig. 8.3
DNA base pairing
•Backbone is
deoxyribose-phosphate
•Bases are
complementary
•Strands are
antiparallel
Semiconservative
Replication
Single Parent Strand
serves as a template for the
new daughter strand
Only occurs 5´ to 3´
How?
Fig. 8.6
Origin of replication
• Replication fork
•
Leading strand - continuous
•
Lagging strand - discontinuous
RNA polymerase
•
RNA primer
•
DNA polymerase
•
DNA ligase