What is Life? Biological Information - Genomics, gene regulation: controlling DNA
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What is Life?
!
Biological Information
• Genomics, gene regulation: controlling DNA
Erwin Schrödinger
• Genomes!
• Expanding Genomes!
• The Bacterial Operon!
• Levels
!
of control
What is Life? !
Fueling Life: Metabolism
• Photosynthesis, oxidative respiration
SPU 20 Fall 14
This Fire Franz Ferdinand
Mid-term Feedback!
!
Erwin Schrödinger
Thank you!
!
1. More ‘big picture’ contextualization!
2. More in-class activities!
3. Better jargon control (esp. Bio)
What is Life? !
SPU 20 Fall 14
Plant species chromosome numbers: the
preponderance of even numbers suggests a
significant role for genome-doubling through
polyploidy in evolution
(Plants)
Genome Duplication
3
Segment Duplication: Hemoglobin Gene Family
Segment Duplication
Globin use profile through development
4
A new gene is born: transposition of genetic material
1.
ancestral gene ancestral gene duplicate
Local Duplication
The creation of a novel functional gene, Jingwei, in Drosophila
through the transfer from one chromosome to another of part of
the alcohol dehydrogenase gene, and its insertion into another
gene
5
A new gene is born: transposition of genetic material
1.
ancestral gene ancestral
new hybrid
genegene,
duplicate
Jingwei
exons
2.
alcohol dehydrogenase gene
introns transcription
edited RNA transcript!
(introns removed)
3. Reverse transcription!
(RNA => DNA)
The creation of a novel functional gene, Jingwei, in Drosophila
through the transfer from one chromosome to another of part of
the alcohol dehydrogenase gene, and its insertion into another
gene
6
Jingwei ( or is the name of a
character in Chinese mythology. Originally
the daughter of the emperor Yandi, she
perished at a young age in the East Sea. After
her death she chose to assume the shape of a
bird in order to exact revenge upon the sea
by dropping into the sea stones and small
twigs from nearby mountains in an effort to
fill it up
7
What is Life?
!
Biological Information
Erwin Schrödinger • Genomics, gene regulation: controlling DNA
• Genomes!
• Expanding Genomes!
• The Bacterial Operon!
What is Life? !
• Levels of control
SPU 20 Fall 14
8
Regulatory proteins often bind DNA
The “Lac operon” in E. coli
9
Stephanie Wang
What is Life?
!
Biological Information
Erwin Schrödinger • Genomics, gene regulation: controlling DNA
• Genomes!
• Expanding Genomes!
• The Bacterial Operon!
What is Life? !
• Levels of control
SPU 20 Fall 14
11
12
Gene expression can be controlled at
multiple levels
14
1. Chromosome
inactivation
15
2. Transcription
16
Epigenetic modification of DNA (with
chemical tags) to turn on/off genes
A signal transduction
pathway is a form of
long distance control of
transcription
18
protein-coding segments of a gene
3. Post-transcriptional Introns
control non-protein-coding segments of a gene
Alternative splicing
19
4. Post-translational control
Production and secretion of insulin are largely independent; prepared insulin
is stored awaiting secretion.
205. Development: a hierarchical
cascade of gene switching
21
What is Life?
!
Fueling Life: Metabolism
!
Last universal common ancestor
Erwin Schrödinger
• LUCA!
• Extremophiles: microbial metabolic diversity!
• Oxygenic Photosynthesis!
• Great Oxygenation Event!
What is Life? ! • Oxidative Respiration!
• Evolution of Eukaryotes
SPU 20 Fall 14
2223
Adenosine triphosphate (ATP)
2425
An Anaerobic World
Lactate
fermentation
26What is Life?
!
Fueling Life: Metabolism
!
Erwin Schrödinger
• LUCA!
• Extremophiles: microbial metabolic diversity!
• Oxygenic Photosynthesis!
• Great Oxygenation Event!
What is Life? ! • Oxidative Respiration!
• Evolution of Eukaryotes
SPU 20 Fall 14
27
Tree of Life
You are here
28Extremophiles
• the ability to survive in environments previously deemed inimical to life!
• an array of metabolisms
29
Thermophiles,Yellowstone
3031 32
What is Life?
!
Fueling Life: Metabolism
!
Erwin Schrödinger
• LUCA!
• Extremophiles: microbial metabolic diversity!
• Oxygenic Photosynthesis!
• Great Oxygenation Event!
What is Life? ! • Oxidative Respiration!
• Evolution of Eukaryotes
SPU 20 Fall 14
33
Cyanobacteria, photosynthetic bacteria
34Bloom of cyanobacteria in a Guatemalan lake
35
Converting electromagnetic energy into chemical energy
Step 1!
Light Dependent
6H2O + 6CO2 C6H12O6+ 6O2
36Step 2!
Light Independent
37
38What is Life?
!
Fueling Life: Metabolism
!
Erwin Schrödinger
• LUCA!
• Extremophiles: microbial metabolic diversity!
• Oxygenic Photosynthesis!
• Great Oxygenation Event!
What is Life? ! • Oxidative Respiration!
• Evolution of Eukaryotes
SPU 20 Fall 14
39
Isotope fractionation analysis suggests that
photosynthesis arose considerably earlier
than 2.4 MYA. Why do you think that we had
to wait until 2.4 MYA for oxygen to start
accumulating in the atmosphere?
40The Great Oxygenation Event!
Approx 2.4 billion years ago
Sunlight
oxygen!
Cyanobacteria
41
Another !
Anaerobe!
***!
1. Mass Extinction Oxygen !
Victim
Sunlight
oxygen
Cyanobacteria
42Palm House Kew Gdns, Decimus Burton 1848
Over 100 years,!
2. Greenhouse ! methane has 25 times the
greenhouse impact of the
crisis same amount of carbon
dioxide
CH4 + 2 O2 → CO2 + 2 H2O
Sunlight
methane, a major component of the early atmosphere
oxygen
Cyanobacteria
43
44“Snowball Earth” An Ice Age that Goes Global
How did life survive?!
!
•! Reservoirs of anaerobic and low-oxygen life powered by chemicals in
deep ocean hydrothermal vents (no photosynthesis)!
•! Quiescent cells and spores! !
• Under the ice layer, as chemolithotrophs like those we see today in
modern glacier beds, and in high-alpine and Arctic permafrost. !
• In small oases of liquid water associated with geothermal activity!
How did it end?!
!
•! Gradual replenishment of green house gases through volcanic activity!
45
463. Adding the Ozone
Umbrella Ozone formation (and destruction)
Ozone is continuously created and destroyed in the
atmosphere by UV radiation. This highly energetic UV
Sunlight radiation is called UVC (wavelength 280 nm) and is very
harmful for human health. UVC is fully absorbed in the
atmosphere by oxygen and ozone molecules. Ozone also
absorbs UVB radiation that is less energetic (wavelength
oxygen 280 - 325 nm) but is also harmful
Cyanobacteria
47
48The ozone layer permits:!
!
• life in shallow water (which in
turn facilitates higher rates of
photosynthesis)!
!
• life on land
49
What is Life?
!
Fueling Life: Metabolism
!
Erwin Schrödinger
• LUCA!
• Extremophiles: microbial metabolic diversity!
• Oxygenic Photosynthesis!
• Great Oxygenation Event!
What is Life? ! • Oxidative Respiration!
• Evolution of Eukaryotes
SPU 20 Fall 14
50C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
51
What is Life?
!
Fueling Life: Metabolism
!
Erwin Schrödinger
• LUCA!
• Extremophiles: microbial metabolic diversity!
• Oxygenic Photosynthesis!
• Great Oxygenation Event!
What is Life? ! • Oxidative Respiration!
• Evolution of Eukaryotes
SPU 20 Fall 14
52Early eukaryote fossils!
(from as early as 1.5
billion years ago)
53
Prokaryote
0.2-10µm 5-100µm
5455 The Origin of the Nucleus? 56
Phylogenetic anomalies suggest
the origin of organelles by
endosymbiosis
57
5859 60
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