Download You Light Up My Life

Information
• Today
– Chapter 14 and 16 highlights
• Wed., 30 November
– Final exam review – BRING YOUR QUESTIONS!
– Instructor evaluations
• Mon., 12 December, 2:15-4:15pm in C317
– Final Exam
• [email protected]
• Office: B-203 (by appointment)
Chapter 14
READ:
– Key Concepts
– 14.1
– 14.2
DNA to Proteins
1) DNA is transcribed to form RNA
2) RNA is translated to form polypeptide
chains, which fold to form proteins
3 Classes of RNAs
• Messenger RNA (mRNA)
– Protein-building instruction
• Ribosomal RNA (rRNA)
– Major component of ribosomes
• Transfer RNA (tRNA)
– Delivers amino acids to ribosomes
Base Pairing during
Transcription
DNA
G
C
A
T
RNA
G
C
A U
DNA
C
G
T
A
DNA
C
G
T A
base pairing in DNA replication
base pairing in transcription
Transcription
• Small DNA stretch = template
• RNA polymerase = enzyme
• Product = 1 RNA strand
transcribed DNA
winds up again
DNA to be
transcribed unwinds
mRNA
transcript
PROTEIN INSTRUCTIONS
RNA
polymerase
Genetic Code
• 64 base triplets
• Triplets = codons
– 61 = amino acids
– 3 = stop
Figure 14.7
Page 230
tRNA Structure
codon in mRNA
BRINGS AMINO ACIDS
TO RIBOSOMES
anticodon
amino-acid
attachment site
amino
acid
OH
Figure 14.8
Page 231
Transcription
Overview
mRNA
Mature mRNA
transcripts
Translation
rRNA
ribosomal
subunits
tRNA
mature
tRNA
Chapter 16
READ 16.2, 16.4
Double-stranded
DNA to copy
Polymerase
Chain
Reaction
(PCR)
DNA heated to
90°– 94°C
Primers added to
base-pair with
ends
Mixture cooled;
base-pairing of
primers and ends
of DNA strands
Stepped Art
Figure 16.6
Page 256
DNA polymerases
assemble new
DNA strands
Polymerase
Chain
Reaction
Mixture heated again;
makes all DNA
fragments unwind
Mixture cooled; basepairing between
primers and ends of
single DNA strands
Stepped Art
Figure 16.6
Page 256
DNA polymerase
action again
doubles number of
identical DNA
fragments
Gel Electrophoresis
•
•
•
•
DNA placed at one end of a gel
A current is applied
DNA molecules (-) move to + end
Small molecules faster than large
Nucleotides for Sequencing
• Standard nucleotides (A, T, C, G)
• Modified versions
– Fluoresce
– Stop DNA synthesis
Reactions Proceed
• PCR
• Stops with modified nucleotide
• Millions of copies of varying length
Recording
the
Sequence
Figure 16.8
Page 258
TCCATGG
TCCATG
TCCAT
TCCA
TCC
•DNA placed on gel
•Fragments move by
TCCATGGACC
TCCATGGAC
TCCATGGA
TC
T
electrophoresis
gel
one of the many
fragments of
DNA migrating
through the gel
size
•Pass through laser
beam
•Color of each fragment
one of the DNA fragments
passing through a laser beam
after moving through the gel
is recorded on printout
T C C A T G G A C C A
Information
• Today
– Chapter 14 and 16 highlights
• Wed., 30 November
– Final exam review – BRING YOUR QUESTIONS!
– Instructor evaluations
• Mon., 12 December, 2:15-4:15pm in C317
– Final Exam
• [email protected]
• Office: B-203 (by appointment)