1947: Erwin Chargaff

%T=%A
%G=%C

30.9% Adenine
29.4% Thymine
19.9% Guanine
19.8% Cytosine

Mauice Wilkins and Rosalind Franklin used x-ray crystallography to study the structure of DNA

In this technigue,, x-rays are diffracted as they passed throuh aligned fibers of purified DNA
The diffraction pattern can be used to deduce the three dimension shape of molecules

James WAtson learned from their research that DNA was helical in shape and he deduced the with of the helix and the spacing of bases.

The ladder makes a twist every 10 base "3.4"

Each side is anti parallel

The nitrogenous bases are held by weak hydrogen bonds
A-2 bonds
T-2 bonds
C-3 bonds
G-3 bonds

Paring with like nucleotides did not fit the unifor diameter
Purine to Purine was to wide
Pyrimidine to Pyrimidine is to small

Watson and Crick's modle, semiconservative replication, predicts that when a double helix replicates each of the daughter molecules will have one old strand and one newly made strand.

Other competing modles, the conservative modle and the dispersive model, were also proposed

In the late 50s matthew meselson and franklin stahl suported the semiconservative model

In theri experiments they labeld the nucleotides of the old strands with a heavy isotope of nitrogen(15n) while any new nuclecotied would be indicated by a lighter isotope (14n)

PThe frist replication in 14n nedium produced a band of hybride 15-14n dna eliminated the conservative model

The second replication produced both light and hybrid dna whic eleminated the dispersive model

It takes e. coli less than an hour to copy each of the 5 million base pairs in its sinle chromosome and divde to form 2 identical daughter cells

A human cells can copy its 6 billion base pairs and divide into daughter cells in only a few hours

This process only has one per billion nucleotides

The replication of a DNA molecule begins at special sites, orgins of replication

At the orign sites the DNA strands searate forming a preplcation buble with replication forks at each end.

The bubles elongate at the DNA is replicateed and eventually fuse.

1000s of bubbles

DNA polymerases catalyze the elongation of new DNA at the replication fork

As nucleotides align with complementray bases along the template strand by the polymerase

500 per second in bacteria
50 per second in humans

The raw necleotides are nucleoside triphosphate
when the phosphate bonds break the energy is used to connect the nucliotides together

DNA polymerase can only add from 3' to 5'
The leading strand copies toward the fork while the lagging strand copies away from the fork

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1. In respiration the final acceptor for electrons from NADH is oxygen. This not only regenerates the nad+ required for glycolysis but pays an ATP bonus when the stepwise electron transport from NADH to oxygen drives oxidative phosphorylation. An Even bigger ATP payoff comes from the oxidation of pyrubated in the Krebs cycle, which is unique to respiration. Without oxygen, the energy still stored in pyrubate is unavailable to the cell. Thus, cellular respiration harvest much more energy from each sugar molecule than fermentation can. Pyruvate is a fork in metabolic road that leads to 2 different catabolic routes. Under aerobic conditions (oxygen present) pyruvate can be converted to acetyl CoA and respiration can take its course.

3. The H+ gradient is referred to as a proton-motive force. It drives H+ ions back across the inner mitochondrial membrane. ATP synthase is a molecular mill. It is a protein complex that, powered by the flow of hydrogen ions, pumps hydrogen ions across the mitochondrial membrane. A cylindrical rotor within the membrane spins clockwise when H+ flows through it dow the H+ gradient. A rod connection the cylindrical rotor and knob also spins, activating catalytic sites in the knob. A protruding knob contains catalytic sites that join the inorganic phosphate to ADP to make ATP. Once the H+ is pumped across the gradient it couples with redox reactions of the electron transport chain to ATP synthesis. This coupling mechanism is called chemiosmosis.

4. Cellular respiration is governed by supply and demand. If little ATP is in a system then the cell speeds up the process of cell respiration and acetyl CoA is created from pyruvate and goes through the Kreb cycle. If acetyl CoA is abundant and oxygen then reparation can occur and lots of ATP can be created. If too much ATP is present then it acts as a feedback mechanism to slow down the production of ATP This insures that the cell will not waste energy making more of a particular substance than it needs. Also it keeps the production of ATP at a maintainable pace.

6. Aerobic respiration can make up to 38 ATP while fermentation only makes 2 because respiration uses the potential energy stored in NADH.

7. Glucose first goes through glycolysis. It enters the cell and is phosphorylated by the enzyme hexokinase, which transfers phosphate group from ATP to the sugar. Then the Glucose-6-phosphate is rearranged into Fructose-6-phosphate. From there another phosphate is added and the molecule becomes Fructose-1,6-bisphosphate. Then it splites to 2 Glyceraldehyde-3-phosphates. These each produce 2 ATP. They are rearranged to 1,3-Bisphoglycerate. Then one phosphate group is detached and one ATP is gained each. The remaining phosphate group is moved to form 2-phosphoglpyruvate with the lose of a water molecule. The last phosphate group is removed and the molecule becomes pyruvate. If oxygen is present in the system then the pyruvate is pulled into the mitochondrion where a CO2 molecule is taken away and Coenzyme A is add making in Acetyl CoA.

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contents 1 2 3 4 5 6 7 8 9 10 11 12 13 14
h20 9.8 9.4 4.5 9.0 23.5 x x x x x x x x x
0.2 x x x x x 13.6 12.2 14.2 31.5 5.4 x x x x
0.4 x x x x x x x x x x 13.1 5.1 13.3 9.9
0.6 10.4 7.2 4.5 9.3 18.5 x x x x x x x x x
0.8 x x x x x 12.8 12.2 13.4 33 5.6 x x x x
1 x x x x x x x x x x 12.3 11.1 13.7 10.3




contents 1 2 3 4 5 6 7 8 9 10 11 12 13 14
h20 7.2 9.8 5.8 9.2 10.3 x x x x x x x x x
0.2 x x x x x 9.4 12.5 11.5 9.1 4.8 x x x x
0.4 x x x x x x x x x x 10.8 4.5 10.1 7.6
0.6 11.7 11.3 3.7 10.3 6.7 x x x x x x x x x
0.8 x x x x x 13.1 8.5 8.4 6.1 3.5 x x x x
1 x x x x x x x x x x 8.4 9.5 8.4 6.5

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First law of thermodynamics (energy can not be created or distroyed)

Second law of thermodynamics (universe is going towards enthropy)

Anabolic -builds
non spontaneous processes are those that can only occur if energy is added to a system
less stable

catabolic -distroies
Spontaneous processes are take away energy from a system
more stable

Free energy -energy that is avalable to do work (delta)G<0)
G=h-ts

G = free energy
H = total energy
S = entropy
T = tempeture

Free energy can be thought of as a measure of the stability of a system.

Systems that are high in free energy are unstable and tend to moce toward a more stavle state one with less free energy.

Systems that tend to change spontaneously ate those that have high energy, low entroypy or both

in any spontaneous process the free energy of a system decreases

Delta G = G (final state) - G (starting state)

For a system to be spontaneous the system must either give up energy (deacrease in H), give up order (increase

in S), or both

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stupid lausd... trying to block my email --yahoo AND gmail-- sheesh.
well this is my way around it... NuTang blog of typed homework and notes ecessable everywhere.. kinda like the memos feature but it doesnt pile up on you... its not something for you to enjoy really unless you like Greek history and amino acid side chains.

Greece in the Archaic Age: Development of Trade

Due to Greece’s poor soil, little rainfall and rough, nounatainous terrain Greeks were forced to develope a system of trade to survive. The population of Greece did not increase during the dark ages because of damage the Dorians inflicted on Myceneaen culture. The trade that used to go through Greece now is done by Arameans and Phoenicians. As the Greeks start to settle down once again they get many benifits of this trade but don’t have any control over it yet.
Meanwhile the first empire of the world is being formed by the Assyrians. They Assyrians used their huge expanse of control to protect the many trade routes that go through the agean and medateranian sea. With the help of the Assyrian naves piracy begings to curtail and no longer to greek merchants have to fear being robbed of their goods by pirates. Now trade can flow much easier to and from Greece. Also the high class is interested in other things than just food like luxuries.
In order to get luxuries of the outside world Greek nobles have to have something to exchange for them. They had some crops but they need them to survive so they had to look for alternatives. One thing that they did have was greak soil of pottery. During the Archaic age Greek pottery became a very popular item of trade and put Greece as a major player in economic market.
In parallel to the development of trade was the development of “polis” and city-states. As far back as the begining of the Dark Ages Greeks had a strong sense of pride for their community. They lived in small nomadic tribes with a political system consisting of a leader who wasnt that different than the rest of the society and a counicl that would come up with ideas for the rest of the people to vote on. This early community of wandering waring people started to settle down but they still kept the same basic system intact. They all settled into individual valleys which became different states that acted as their own country seperated by mountains from other states. The cultural center of each state was called a polis; there were about 200 poli in Greece. Every Greek did not regard them self as a member of Greece but as a member of their particular poli. This extream pride of their homeland produced many wars and competitions. Greeks would not only fight over crop land, animals and raw materials but also the arts. They would try to out do eachother by making the best pottery of sculpture. This competitiveness helped push Greek goods to the top of the market. As Greeks started accnologing wealth as an important part of charater or arete they looked for ways to get rich.
There were three main ways for a Greek to get money. They could sell their abilities in battle as merchenaries, start wars on their own to steal goods or as already stated in the above paragraphs they could use trade. People would become merchants or leave their polis for good and start a trading post. These trading posts could become polis of there own and were basically colonies. Including these coloines there were around 1500 Greek poli stretching form north Eygpt to the black sea and over to italy and even spain. These colonies greatly affected greek culture by introducing new ideas into greece and eventually give birth to the rise of philosophy and reason.

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