basic oxygen

When was the origin of earth

4.5 billion years ago

how do you get deuterium?

interaction of a proton with a neutron

100 seconds after the big bang what was the proton to neutron ratio?

7:1 protons to neutrons
halflife 610 seconds (~6 min)

What is the stable helium neucleus

helium 4
4He

as the universe cools what is the ratio of hydrogen to helium?

3:1 hydrogen to helium

What is primordial nucleosynthesis?

100 seconds after the Big Bang

Deuterium --\> 4-He (3:1 ratio of 1-H to 4-He)

In the first 100 seconds of the universe... H, He and trace amounts of Li and Be

What is the stability gap?

Occurs when Neutrons + Protons \= 8
Cannot jump past 7-Li to get to 8-Be; it is too unstable to add a proton and a neutron.

There is a similar gap from 4-He to 6-Li

Most common elements

hydrogen
helium
oxygen
carbon
neon
iron
nitrogen
silicone
magnesium
sulfur

proton- proton chain

proton and proton act becoming deuterium- have to convert a proton into neutron releases energy that can make more helium

How many years ago can the origin of oxygen in the universe be dated to?

14 billion years ago

What is the stability endpoint?

56-Fe

Anything undergoing fission will fission down to 56-Fe
Anything undergoing fusion will fuse up to 56-Fe

How did we get oxygen if we were limited by initial 4 elements? (What were those 4 elements?)

First 4: H, He, trace Li and Be

Stellar nucleosynthesis brought about C and O 14 billion years ago.

2 4-He atoms fused to become a 8-Be (which is very unstable) and then an 8-Be fused with another 4-He to become 12-C.

Then 12-C fused with a 4-He to become a 14-O.

When was the Hadean era? associated milestone?

4.5 billion years ago

lava, brimstone, fire
formation of earth

When was the Archean era? associated milestone?

4 billion years ago

sulfur isotopes
bacterial life began

When was the Proterozoic era? associated milestone?

2.5 billion years ago

Great oxidation event
multicellular organisms

When was the Paleozoic era? associated milestone?

550 million years ago

vertebrates, first land plants, cambrian explosion (complex animals appear)

When was the Mesozoic era? associated milestone?

250 million years ago

dinosaurs (triassic, jurassic, cretaceous)

When was the cenozoic era? associated milestone?

65 million years ago

meteorite killed dinosaurs

What is the permian Triassic boundary?

Major extinction event 251 million years ago between the permian period and the triassic period (between the Paleozoic and mesozoic era)

Earths first atmosphere included....?

Hydrogen and helium

When was the origin of oxygen on earth be dated to?

4.5 billion years ago

What was the classical primordial atmosphere makeup?

A reducing atmosphere! (

UV breakdown of H2O yeilds

some O2

What is the importance of the intital reducing conditions of earth?

• organic molecules could not accumulate in the presence of oxygen

• photosynthesis developed using H2S

• radical defense develops against sulfur radicles

• first life in sea vents, oxygen in ocean would disrupt it

What are volcanic gases comprised of?

50-60% water vapor
24% CO2
13% sulfur
6% nitrogen
trace gases Ar, He, Ne, CH4, CO, H2

Wha is the most abundant in volcanic gases?

water vapor

3.8 BYA origin of life hypothesis

spontaneous generation, primordial soup, meteorites, deep sea vents, multiple genesis (more than one of the above)

when is the origin of life on earth dated to ?

3.5 billion years ago (3.8 billion years ago)

what is abiogenesis?

life from non-life

also known as biopoiesis

What are the main points of the Hypothesis of spontaneous generation? Who was involved with this hypothesis?

• ancient, Aristotle

• believed in abiogenesis

Redi and Pasteur showed it does not work "omne vivum ex vivo"

spontaneous generation hypothesis

Haldane-oparin 1920s

• Oparin, Urey, Miller, Fox

-Darwin's warm little pond

• electric sparks

• community clay

• chilly start (UV protection by surface ice)

• radioactive beach hypothesis

meteorites hypothesis

• panspermia (billions of exoplanets

• Arrhenius 1903 Wickramasinghe and Hoyle 1970's

• exogenesis chirality

• Murchison meteorite (1969) L-amino acids, purines, prymidines

Deep sea vents hypothesis

-Günter Wächtershäuser: Iron-sulfur world

• Black smokers

• White smokers (deep hot biosphere model, thermosynthesis)

• Hydrogen spewing

• Metabolism came first (iron-sulfur world hypothesis, Zinc world hypothesis, Wächtershäuser, 1980's)

3.5 BYA

• Water - (from comets?) is a prerequisite

• LUCA (last universal common ancestor)

• Bacteria and Cyanobacteria (blue-green algae) single cells (3.5 bya?)

• Anerobic prokaryotic synthesizers

• "Oxygen Whiffs"

• "The great oxidation event" 2.3 - 2.35 bya - Holland

• "Snowball earth(s)" - Kirschvink

• Precambrian life altered the atmosphere

• Eukaryotic aerobes (~1.5 bya - 800 mya)

• Banded Iron Formations (BIFs) (but purple bacteria too)

• Mass-independent fractionation of sulfur isotopes (MIFs) - Farquar et al Science 2000, Kump Nature 2008

What is significant about banded iron formations?

Give insight into the change of Earth's atmosphere over the course of time (from reducing to oxidizing)

earliest evidence of life on earth

What is the "snowball Earth"?

Proposed by Joseph Kirschvink - 1992

Approx 650 mya (Proterozoic era) Earth's surface was nearly entirely frozen. rapidly cooled the earth- positive feedback leads to runaway cooling

Facilitated by equatorial continent distribution

Volcanic activity releases greenhouse gases mainly CO2 which begins the global warming cycle

Glaciation reduces photosynthesis and thus O2 production

When was the GOE (great oxidation event) and what likely induced it?

2.3 billion years ago

- induced by cyanobacteria through photosynthesis. Before the GOE, any free O2 they produced was chemically captured by disolved iron or organic matter. The GOE was the point in time when these oxygen sinks became saturated at which point oxygen, produced by cyanobacteria was free to escape into the atmosphere.

A cooling earth meant less volcanic reducing gases to titrate the O2 from cyanobacteria.

chloroplast provide __% of global photosynthesis

5%

Oxygen accumulation in the atmosphere came from what reaction?

- CO2 + H2O \= CH2O + O2

Carbon dioxide plus water yields formaldehyde and oxygen gas.

Excess oxygen comes from loss of formaldehyde by burial of organic matter in earth crust

What is pyrite?

Fools gold (iron sulfide)

" fermentation is life without oxygen. Fermentation of organic compounds in the absence of oxygen. Substrate level oxidation."

Louis pasteur

""The atavistic genes of modern organisms often betray their evolutionary roots"

Nick Lane

What is the energy equation for life?

2H2 + O2\= 2H2O + E

Life requires energy. Life is separation of the energy state of the universe. Life is a state of dynamic disequilibrium

What is the prevailing view of atmospheric oxygen evolution over time?

That proxies set an upper limit for oxygen levels before 2.45 bya and a lower limit after that time.

The record of oxidative weathering after 2.45 bya ago sets a lower limit for oxygen levels at 1% of present atmospheric level and and upper limit of 40% (inferred from the evidence of the anoxic oceans during the Proterozoic). There are tighter bounds on O2 from 420 mya to the present which is set by a continuous record of charcoal accumulation: flames cannot be set below an oxygen level of 60% PAL and above 160% of PAL.

What does the oxygen level need to be for flames to render (in regards to PAL)?

Needs to be at least 60% PAL and can't be more than 160% PAL.

What happens during the Precambrian era?

beginning of life, photropic bacteria, cyanobacteria plus phototrophs, macroscopic eukaryotes, and the beginnings of algae and shelly invertebrates

It covers 90% of the history of the Earth up until 600 mya.

After that comes the Paleozoic, the Mesozoic, and the Cenozoic (current era)

When were the first real fossils found?

Boundary of Cambrian
600 million years ago around hte proterozoic era

What is the composition of the current atmosphere?

• oxygen 20% -nitrogen 79%

• carbon dioxide 0.03%

• trace nobel gases

What facilitated warm temperatures?

water and CO2 in the athmosphere allowed warmer temperatures (15C vs. -18c)

What does predation favor?

both growth and size of the predator and prey

oxidation is about 40% efficient so there can be 6 levels where predators can still survive

What are prokaryotes constrained by?

surface/volume because energy production is on the surface

What effect did atmospheric oxygen have on body size and mass?

Exhibited in Drosophila melanogaster

Greater oxygen saturation and tolerance: larger body size and mass

Pre ganglionic concepts

bios, Zoe, psyche, thymos

bios

Mode or duration
"the good life", "life-span", a written life

zoe

Ensemble of actions (zaien \= "to live")
Zoon (a living being), the process of living

psyche

"Soul"
"anima", "breath-soul", "life-soul", life \= breath, confers ability of motion "animation"

thymos

Life
Spirit, elan, courage, heart (as in battle)

quintessential physiology

It was a diagram used in Galen's time that reduced the world down to irreducible elements and had biological components ascribed to them:
Earth (black bile)
Wind (blood)
Water (phlegm)
Fire (yellow bile)

This system worked for a 1000 years to classify people and their illnesses

Empedocles (465bce)

Erasistratus

Pneuma

• pneuma Zotikon- vital spirit arterial

• pneuma psychon- animal spirit in nerves

breath

• anemos- soul

• pneuma- air, breath of life

• psyche- spirit mind

Galen (130-200ce)

Physician to Marcus Aurelius

animal spirits made the muscle move

Leonardi DiVinci (1452-1519)

Air is composed of at lest 2 components

air which does not support fire, does not support life (without oxygen)

William Harvey (1578-1657)

De moto cortis- motion of the Heart

Influenced by Galen

"Pores" in the heart

blood only goes in one direction and has to circulate (showed that there were valves in the venous circulation)

recognized that the blood flows rapidly around hte humban body being pumped through a single system of arteries and veins

investigated the heart beat

made diagram of the heart as a pump

Malpighi (1628-1694)

Proved Harvey's hypothesis by modeling it on a frog (gave Harvey's concept a mechanism)

Evangelista Torricelli (1608-1647)

Invented the mercury barometer and demonstrated the existence of a vacuum (although did not publish it because it was scientific heresy; went against Aristotle's findings that were supported by the Church)

What did pascal contribute?

Substantiated Torricelli's ideas of vacuum and showed that air has weight that is diminished by height

what did Dalton and Boyle contribute?

• daltons law of partial pressures

• Boyle showed that in a partial vacuum animals die and flames go out

Joseph Black (1728-1799)

• invented analytic balance

• discovery of fixed air (carbon dioxide) by pouring acid on chalk and capturing the bubbles (heavier than air)

Henry Cavendish (1731-1810)

discovers hydrogen in (1766) thinks its phlogiston

makes water by burning hydrogen finds 2:1 ratio with dephlogisticated air

proves water is a non-essential element because it can be broken down into parts

figured out air was 20% oxygen

Daniel Rutherford (1749-1819)

Student of Joseph black

1772 discovers nitrogen

called it noxious air or phlogisticated air

What is phlogistin? When was the theory prominent?

1667-1774

When you burn something, it weighs more because you're adding something (we know now that it's oxygen)
But they thought it was because of the fire principle that was being taken away and termed them phlogistin reactions.

So phlogisticated air is when you take oxygen out of the air. Essentially, the air is so saturated with "phlogistin" that you can't light a fire.

Who theoretically discovered oxygen then?

Priestley* b. 1733-1804
Lavoisier*

Joseph Priestley (1733-1804)

De-phlogisticated air

Worked in a brewery noticed CO2 put out flames

If you scooped the air over the beer and passed it into water you get something refreshing- invented carbonated water (known as Black's fas, or fixed air, into water) which was proposed as a cure for scurvy.

Discovered HCl named it muriatic acid

Discovered O2 via a nitric oxide assay, he generated O2 by burning mercuric oxide

discovered CO when he moved to Pennsylvania

Carl Scheele (1742-1786

discovered fire air but did not realize its biological implications in respiration nor its role in combustion.

discovered oxygen but called it fire air

Antoine Lavoisier (1743-1794)

Used Scheele's and Presitley's research and "discovered oxygen"

Worked for the FrenchArmy producing gunpowder, colelcted taxes, became nobility and was later executed in the French Revolution

wrote a treatise on oxygen without crediting Priestly

Named oxygen because he thought oxygen is what made acid and acid (literally acid generator)

collected oxygen with burning (like Scheele)

replaced the phologistin theory with Joseph Black's Caloric theory (heat consist of a self-repellant fluid that flows from hotter to colder bodies)

What were the eight sages that contributed to the discovery of oxygen?

Priestley
Lavoisier
Scheele
Cavendish
Ibn al-Nafis
Servetus
Sendivogius
Mayow

Ibn al-Nafis (1213-1288)

Described the pulmonary circulation

Michael Servetus (1511- 1553)

Described blood flowing through the lungs and how it changed color doing so (oxygenated vs. deoxygenated blood)

Michael Sendivogius (1566-1636)

Air contains the "Secret Food of Life" - gas emitted by potassium nitrate when heated

John Mayow (1641-1679)

Wrote about air he names SPIRITUS NITRO-AEREUS. He said it is consumed in the fire and that our body utilizes it to provide body heat and energy.

Who was Edward Morley?

• A professor here at Western Reserve;

• Worked in the Sanitary Commmision during the Civil War where many soldiers died of dysentery. Also did forensic science as a side job as well as maintained a clock in Cleveland.

• STUDIED THE CONCENTRATION OF O2 in various spots and altitudes around the world and came up with the Morley-Loomis hypothesis that states O2 % is constant everywhere (21%)

• With Michaelson found the atomic weight of O2 and 15.879 which worked to refute Prout's hypothesis that atomic weights were only whole number integers of hydrogen

What are the most important isotopes of oxygen? Which are stable and not stable?

STABLE
16-O (99.76%)
17-O (0.04%)
18-O (0.2%)

NOT STABLE
15-O (used as a positron emitter e.g. PET scans and in metabolic experiments)

What oxygen isotope is used for nuclear magnetic resonance (NMR)?

17O

which oxygen isotope is used in PET?

15O unstable

What are some uses of the isotopes of oxygen?

16-O and 18-O have changed over time with temperature so measuring the concentrations of these as a ratio we can extrapolate temperatures in different time periods

15-O is a positron emitter that is used in PET scans and in metabolic experiments

17-O has a large NMR singlet (5:2 nuclear spin, whereas the other isotopes do not have spins)

What is the Cunningham Steel Ball?

It was built in Cleveland and was used for hyperbaric oxygen therapy. After the AMA declared such therapy was quackery, it was dismantled and used in military vehicles.

pressure was 1.3-1.4 atm

oxygen was thought to improve health

Pathologies associated with hyperoxia:

Lorrain-Smith effect:

Lung damage due to oxygen intoxication

studied high oxygen exposure on the lungs

Pathologies associated with hyperoxia:

Paul Bert effect:

Acute CNS symptom where among patients placed in a hyperbaric oxygen the first problem that was induced was seizures

when you reach 4 atm you start to have seizures

Pathologies associated with hyperoxia:

John Bean effect:

Chronic spinal paralysis (at pO2s that weren't quite enough to cause the Lorrain-Smith effect, paralysis could occur)

spinal cord paralysis, hyperoxia affects the nervous system before anything else

1 RAD exposure

3ppm oxygen

What are the different states of oxygen in terms of orbitals?

Ground state triplet diatomic oxygen has 2 unpaired electrons with parallel spin in the 2p pi* orbitals \-- is a diradical

Singlet delta O2 (ground singlet state) has one set of paired electrons in the 2p pi* orbital

Singlet sigma O2 (excited singlet state has two unpaired electrons with opposite nuclear spin (shortest half life; highly reactive) \-- is a radical \-- least stable

What is the first reduction state of diatomic oxygen?

Superxoide anion

Oxygen →+ 1 e-→ Superoxide anion radical →+ 1 e-→ Peroxide → + 1 e-, + H+ → Hydroxyl radical → +1 e-, +H+ → H2O

What is a radical?

A molecule with an unpaired valence electron (unpaired electron in outermost shell)

Are radicals inherently more dangerous?

Not necessarily.

Example, ground state triplet oxygen has two unpaired electrons while peroxide does not have unpaired electrons yet it is more reactive than the diradical ground state triplet diatomic oxygen.

What is the Fenton reaction? What does it show?

Fe2+ H2O2 → Fe3+ + OH* + OH-
Fe3+ + H2O2 → Fe2+ + HOO* + H+

Free iron is dangerous as is seen in hemolysis (breakdown of hemoglobin)

Haber-Weiss elaborates on the Fenton reaction → wherever you have free iron, there is radical production which can be buffered by proteins.

What are the defenses the body has against ROS?

Avoidance
safe use
enzymatic
quenching

Defense against ROS:

Avoidance

oxygen is kept away from processes and organs unless it's necessary (blood flow control)

Defense against ROS:

Safe Use

e.g. cytochrome oxidase (binds oxygen and holds it in a pocket until 4 e- are transferred and then water is released)

Defense against ROS:

Enzymatic

superoxide dismutase/catalase

glutathione peroxidase (reduces H2O2 by transferring electrons from peroxide to glutathione; the amount of oxidized glutathione, GS-GS, can be measured against reduced glutathione to get a measure of oxidative stress)

Defense against ROS:

Quenching

Vit E - (fat-soluble, takes longer to work) grabs the electron from the radical

Vit C - regenerates Vit E (water-soluble, works immediately)

beta-carotene

What is lipid peroxidation in the context of ROS?

Has to do with how quenching agents like Vit E and Vit C can protect AGAINST lipid peroxidation which is explained thusly:

If a radical attacks double bonds in a lipid it can produce a molecular rearrangement and interact with the next lipid in the chain causing a propagation of rearrangements and ultimate destruction of the membrane fluidity and ultimately kill the cell.