4 Flashcards
1
Q
Where Did It All Begin?
A
The Big Bang Theory
2
Q
The Big Bang
A
- Interstellar dust and gases disturbed by a nearby
supernova - Gravity causes matter to coalesce into sun, planets,
moons, asteroids, comets, etc. - Formation requires more than 100 million years
3
Q
The Earth was likely formed roughly __________
A
5,000,000,000 years ago
4
Q
The age of the Earth
ACCORDING TO SCIENCE
A
4.6 billion years
5
Q
The age of the Earth
ACCORDING TO THE
BIBLE
A
6,000 years
6
Q
evidence of the Big Bang
A
Microwave radiation
7
Q
They detected leftover, cooled down radiation
by carefully scanning the sky with a device called the Holmdel Horn
Antenna. Their discovery was important evidence in support of the Big Bang
Theory and won them the Nobel prize in 1978.
A
Arno Penzias and Robert Wilson
8
Q
Arno Penzias and Robert Wilson detected leftover, cooled down radiation
by carefully scanning the sky with a device called the ___________
A
Holmdel Horn Antenna
9
Q
Atmosphere mostly contained:
A
H2
Methane
CO2
Carbon Monoxide
and not much O2
10
Q
The Environment for Life
A
- Volcanic Hot Springs
- Oceanic hydrothermal vent system
- Deep (below the level of UV penetration)
- Clays and/or Zeolites as templates
- Similarity with present day
chemosynthetic heterotrophic organisms
11
Q
BIRTH OF AN ISLAND
A
Surtsey Island, Island
12
Q
BIRTH OF AN ISLAND
A
*Formed on November 1963
*Formed in a volcanic eruption
originating in the Mid-Atlantic Ridge
*A classic site for the study of biocolonization of founder populations
13
Q
*Formed on November 1963
*Formed in a volcanic eruption
originating in the __________
*A classic site for the study of biocolonization of founder populations
A
Mid-Atlantic Ridge
14
Q
- Dark, billowing clouds of hot hydrothermal fluid are rich in
dissolved metals. - As they rise into the cool ocean water, they precipitate these
metals along the sides of the vent, thus creating a “chimney”
that builds over time.
A
Black smokers
15
Q
- Dark, billowing clouds of hot hydrothermal fluid are rich in
dissolved metals. - As they rise into the cool ocean water, they precipitate these
metals along the sides of the vent, thus creating a “__________”
that builds over time.
A
chimney
16
Q
- The __________ also provide nutrients to a variety
of unusual plants and animals that
congregate around the vents in an area of
the ocean where life would generally not
exist.
A
fluids
17
Q
Chemical Development of Prebiotic Organic Compounds -How?
A
- Bada and Miller’s “sub-ice organic gazpacho” theory
(ice as a catalyst for abiosynthesis reactions) - Amino acids of extraterrestrial origin
– Carbonaceous chondrite meteorites contain organic
compounds, amino acids,etc.
– Murchison Meteorite, Australia (L) and Allende Meteorite (~2
tons), Mexico (R)
18
Q
Bada and Miller’s theory
A
“sub-ice organic gazpacho”
19
Q
(ice as a catalyst for abiosynthesis reactions)
A
Bada and Miller’s “sub-ice organic gazpacho” theory
20
Q
– Carbonaceous chondrite meteorites contain organic
compounds, amino acids,etc.
– Murchison Meteorite, Australia (L) and Allende Meteorite (~2
tons), Mexico (R)
A
Amino acids of extraterrestrial origin
21
Q
contained amino acids not occurring in chemical
systems of living things on earth (exotics). It has been hypothesized that life
originated out in space and came to earth inside a meteorite.
A
The Allende Meteorite
22
Q
do not come from Mars,
but from elsewhere in
space — most likely they
are remnants of spent
comets
A
terrestrial nanobacteria
23
Q
The Murchison forms are interpreted to represent
an indigenous population of the preserved and
altered carbonized remains (microfossils) of
microorganisms that lived in the parent body of
this meteorite at diverse times during the past 4.5
billion years (Gy). —
A
Richard B. Hoover
24
Q
*Made of layers of sediments that contain
Precambrian fossils of bacteria and
Cyanobacteria
*About 3.5 million years old
*Layers reflect the presence of
communities of many types of microscopic
organisms
*Became mineralized and preserved in rock
layers
A
stromatolites
25
*Internal layering and close-up of ___________. Surface is covered by a felt of cyanobacterial filaments that trap sediment grains that are washed
across the mat surface. Abundant sediment supply produces granular laminae, low
sediment supply produces layers rich in organic matter (green in drawing).
columnar stromatolites
26
The ___________ was the age of microbes, macroscopically expressed in colonial
structures that we call stromatolite
Precambrian
27
*helped in the evolution of early multicellular animals by radically increasing
oxygen levels in lakes and lagoons
*microbial mats contained four times more
oxygen than the virtually lifeless water
above – sufficient to support early multicellular animals such as worms and larvae.
*Multi-cellular animals first evolved during
the Ediacaran period, around 635 to 542
million years back, when level of oxygen
were merely 10 per cent of today's levels.
*Early mobile animals might have evolved in
such an environment, living in the biomats
and creating burrows similar to those found
in Ediacaran-aged rocks.
Bacterial mats
28
**Bacterial mats**
*helped in the __________ of early multicellular ____ by radically increasing oxygen levels in lakes and lagoons
evolution, animals
29
**Bacterial mats**
microbial mats contained four times more
_______ than the virtually lifeless water
above – sufficient to support early multicellular animals such as worms and larvae.
oxygen
30
**Bacterial mats**
Multi-cellular animals first evolved during
the ___________, around 635 to 542
million years back, when level of oxygen
were merely 10 per cent of today's levels.
Ediacaran period
31
**Bacterial mats**
_______ might have evolved in
such an environment, living in the biomats
and creating burrows similar to those found
in Ediacaran-aged rocks
Early mobile animals
32
Chemosynthesis: Most Popular Scientific Hypothesis on the Origin of Life
1. Stages
2. Aerobic vs. Anaerobic
3. Lack of free Oxygen >> No Ozone layer
4. Models
33
**Chemosynthesis: Most Popular Scientific Hypothesis on the Origin of Life**
– inorganic production of key simple organic molecules
– production of more complex molecules that can synthesize more of the same
molecule
– development of a genetic code of self-replicating molecules (RNA,DNA,proteins)
– production of the first cell by separation of these codes from the outer world by a
membrane
Stages
34
**Chemosynthesis: Most Popular Scientific Hypothesis on the Origin of Life**
oxygen poisons living cells so early life was anaerobic
Aerobic vs. Anaerobic
35
**Chemosynthesis: Most Popular Scientific Hypothesis on the Origin of Life**
– UV radiation kills cells so life had to originate at depth;
– Water depths of 10m or more
Lack of free Oxygen >> No Ozone layer
36
**Chemosynthesis: Most Popular Scientific Hypothesis on the Origin of Life**
- non-oxidizing secondary atmosphere rich in the constituent chemicals for life--
H2O, CO2, N
– Energy in the form of UV radiation & Hot springs
Models
37
History of the Origin of Life
1828
Synthesis of Urea (Wohler)
38
History of the Origin of Life
1850
Synthesis of Alanine (Strecker)
39
History of the Origin of Life
1861
Synthesis of sugars (Butlerov)
40
History of the Origin of Life
1900
Synthesis of glycine (Klages, Loo, Lingm and Nanji)
41
History of the Origin of Life
1824-1929
Oparin, Haldane, Lipman, Harvey
42
History of the Origin of Life
1953
Miller expirement
43
History of the Origin of Life
1961
Synthesis of adenine
44
Chemical evolution led to the
formation of ________
protocells
45
There is evidence that microspheres (______) could form spontaneously
protein spheres
46
**STAGES IN THE EVOLUTION OF LIFE**
Chemical Evolution
Primitive earth --> gases --> small organic molecules --> macromolecules --> plasma membrane
47
**STAGES IN THE EVOLUTION OF LIFE**
Biological Evolution
Protocell --> cell --> photosynthesis and aerobic respiration
48
- hypothesized that life
formed in the oceans
that formed on early
earth
Alexander OparinRussian scientist (1930s)
49
- tested Oparin’s
hypothesis using electric
spark to substitute for
lightning
Stanley Miller and Harold Urey
(1953)
50
Production of hydrogen cyanide, formaldehyde and 4 different
amino acids from water vapor, methane, hydrogen and
ammonia and electrical sparks
Urey and Miller- 1953
51
* heated 18 different amino acids at 70oC to produce proteins( in water vapor,
CO2, and nitrogen and UV radiation)
* demonstrated that short chain polypeptides could form abiotically from
amino acid monomers through dehydration of amino acid solutions
* artificial proteins were also formed (protenoid microspheres)
spontaneously clumped together when brought into contact with water
* resembled bacteria; lacked nucleic acids
* buds appeared when microspheres were allowed to stand in solution
* lipid-based microcells, called liposomes would form.
Sydney Fox (1959)
52
**Sydney Fox (1959)**
heated __________ at 70oC to produce proteins( in water vapor,
CO2, and nitrogen and UV radiation)
18 different amino acids
53
**Sydney Fox (1959)**
demonstrated that ___________ could form abiotically from
amino acid monomers through dehydration of amino acid solutions
short chain polypeptides
54
**Sydney Fox (1959)**
artificial proteins were also formed (______________)
spontaneously clumped together when brought into contact with water
protenoid microspheres
55
**Sydney Fox (1959)**
resembled bacteria; lacked ______
nucleic acids
56
**Sydney Fox (1959)**
________ appeared when microspheres were allowed to stand in solution
buds
57
**Sydney Fox (1959)**
lipid-based microcells, called _____ would form.
liposomes
58
In solutions of simple organic molecules, two structures
form:
1. Microspheres
2. Coacervates
59
– spherical shaped
proteins that are organized as a
membrane
*Can bud to form smaller microspheres
*Microspheres
60
– collections of droplets of
different molecules, mainly amino
acids and sugars
Coacervates
61
*Both of these can be made in the lab setting.
* yet these cell-like structures are NOT alive
and also lack hereditary characteristics
Microspheres and Coacervates
62
Oparin and Fox formed
formed protobionts, proteinoids, &
microspheres (also called coacervate droplets)
63
Oparin and Fox formed protobionts, proteinoids, &
microspheres (also called ____________)
coacervate droplets
64
These molecular collections mimic cell behavior, but are non-living
Oparin and Fox formed protobionts, proteinoids, &
microspheres (also called coacervate droplets)
65
Coacervates have many of the properties of
life. They:
1. Accumulate monomers and polymers
from solution and grow
2. Divide (though only by budding off
portions of the ‘cell’)
3. Decompose glucose (one form of
metabolism)
4. Trap energy (a primitive form of
electron transport)
5. Have the potential for self-growth
(capable of some RNA and protein
synthesis)
6. Have the potential to undergo a kind of
selection
66
Probably appearance of an early protobiont
- microspheres
- external membrane
- membranous invagination
- RNA or DNA
67
Journey to the modern cell
1. **Evolution starts**
- the first protocell is just a sac of water and RNA and requires an external stimulus (such as cycles of heat and cold) to reproduce.
2. **RNA catalysts**
Ribozymes - folded RNA molecules analogous to protein-based enzymes arise and take on such jobs as speeding up reproduction and strengthening the protocell's membrane. Consequently, protocells begin to reproduce on their own.
3. **Metabolism begins**
Other ribozymes catalyze metabolism-chains of chemical reactions that enable protocells to tap into nutrients from the environment.
68
Biologist John Desmond Bernal coined the term
_________ and suggested that there are a number
of clearly defined "stages”in explaining the origin of
life.
Biopoesis
69
Biologist __________ coined the term
Biopoesis
John Desmond Bernal
70
Biologist John Desmond Bernal coined the term
Biopoesis and suggested that there are a number
of clearly defined "stages”in explaining the origin of
life.
* Stage 1: The origin of biological monomers
* Stage 2: The origin of biological polymers
* Stage 3: The evolution from molecules to cell
71
Bernal suggested that evolution (natural
selection) may have commenced early, some time
between ____________
Stage 1 and 2.
72
Evolution of Cells
* Mitochondria
* Chloroplast
* Modern Endosymbionts
73
– Double membrane system
used in converting organic
molecules into energy
– Has plasmid DNA and
ribosomes
Mitochondria
74
Double membrane system
used in converting energy
into organic molecules
– Has plasmid DNA and
ribosomes
Chloroplast
75
Modern Endosymbionts
- Coral
- Bursaria
- Aphid gut bacteria study
76
Zooxanthellae algae live
within tissues of coral polyp
(an animal)
Coral
77
* Produced without singlecellular green algae
* Acquires through modified
ingestion, then incorporates
into its “body”
Bursaria
78
* Bacteria species is losing its
genome, now just bigger than
that of a mitochondrion’s and
about as dependent on the
“host” organism
Aphid gut bacteria study
79
Two endosymbiotic events
1. Prokaryotic host cell
2. cyanobacterium
