Warm-Up 10/29

1. chloroplasts - make glucose products for the cell (photosynthesis)
Mitochondrion - break down glucose into ATP energy (cellular respiration)

2. Leaf with greater pigment would have a higher rage of photosynthesis because the green color more easily absorbs light photons

3. Temperature - upside "U" (palabara), too hot or cold is bad
Light intensity - peaks at two different intensities
Carbon dioxide - positive correlation and then plateaus

Warm-Up 10/15

1. Describe chemiosmosis as it relates to oxidative phosphorylation.

The last part of aerobic respiration is known as oxidative phosphorylation. In this process, ADP is phosphorylated to generate ATP using the energy that was released from the oxidation (the main substance that was oxidized being NADH + H⁺). The energy from this is released in a series of small steps and then carried out by the electron transport chain. The method used to couple the release of energy by oxidation to ATP production is known as chemiosmosis, where H⁺ moves across the inner mitochondrion membrane down the concentration gradient releasing energy needed for ATP synthase (enzyme) to form ATP.

2. Describe the role of oxygen in the ETC. 

Oxygen is the "final electron acceptor."  As electrons (usually represented as Hydrogen atoms) are passed down the chain, they lose their energy in the making af ATP by phosphorylation.

Warm-Up 10/9

ETC

- group of compounds that pass electrons via reduction oxidation reactions 

- the transfer of protons across a membrane creates a proton gradient.

Warm Up 10/3

I. Cristae - mitochodrion
II. Folds increase surface area so that there is more area to perform chemical reactions. This especially aids in aerobic cellular respiration.

Warm Up 10/7

 Cellular Respiration outline 

Anaerobic (2 ATP, without oxygen) - glycolysis -> lactic acid fermentation OR alcoholic fermentation
Aerobic (38 ATP, with oxygen) - glycolysis -> pyruvate oxidation -> Krebs cycle -> electron transport chain

Glycolysis (2 ATP)
1. Phosphorylation
- addition of a phosphate group
- 2 phosphate groups added to glucose to form hexose biphosphate (provided by 2 ATP molecules)

2. Lysis
- hexose biphosphate splits to form 2 triose phosphate

3. Oxidation
- 2 hydrogen atoms removed from each triose phosphate
- energy released is used to link on another phosphate group, producing a 3-carbon compound carrying 2 phosphates
- NAD+ is the hydrogen carrier

4. ATP Formation
- pyruvate formed by removing 2 phosphates and passing them to ATP

Krebs Cycle
1. acetyl CoA is combined with oxaloacetate to form a molecule of citrate 
2. hydroxyl group and a hydrogen molecule are removed from the citrate structure in the form of water.  The two carbons form a double bond until the water molecule is added back
3. isocitrate molecule is oxidized by a NAD molecule.  The NAD molecule is reduced by the hydrogen atom and the hydroxyl group. NAD binds with a hydrogen atom and carries off the other hydrogen atom leaving a carbonyl group.  This structure is very unstable, so a molecule of CO₂ is released creating alpha-ketoglutarate.
4. coenzyme A returns to oxidize the alpha-ketoglutarate molecule.  A molecule of NAD is reduced again to form NADH and leaves with another hydrogen.  This instability causes a carbonyl group to be released as carbon dioxide and a thioester bond is formed in its place between the former alpha-ketoglutarate and coenzyme A to create a molecule of succinyl-coenzyme A complex
5. free-floating phosphate group displaces coenzyme A and forms a bond with the succinyl complex.  The phosphate is then transferred to a molecule of GDP to produce an energy molecule of GTP.  It leaves behind a molecule of succinate.
6. succinate is oxidized by a molecule of FAD (Flavin adenine dinucleotide).  The FAD removes two hydrogen atoms from the succinate and forces a double bond to form between the two carbon atoms, thus creating fumarate.
7. An enzyme adds water to the fumarate molecule to form malate.   The malate is created by adding one hydrogen atom to a carbon atom and then adding a hydroxyl group to a carbon next to a terminal carbonyl group.
8. Malate molecule is oxidized by a NAD molecule.  The carbon that carried the hydroxyl group is now converted into a carbonyl group.  The end product isoxaloacetate which can then combine with acetyl-coenzyme A and begin the Krebs cycle all over again.

Electronic Transport Chain

- electrons are transported to meet up with oxygen from respiration at the end of the chain
- the overall electron chain transport reaction is:
2 H⁺ + 2 e⁺ + 1/2 O₂ ---> H₂O + energy
- 2 hydrogen ions, 2 electrons, and an oxygen molecule react to form as a product water with energy released in an exothermic reaction.
- energy released is coupled with the formation of three ATP molecules per every use of the electron transport chain.

Warm Up 10/1

1. What is oxidative decarboxylation?
It is reaction in the Kreb's cycle in which oxygen is used to oxidize two carbon atoms to two molecules of carbon dioxide. The two carbon atoms result from the decarboxylation reactions that occur during the Krebs cycle as the six-carbon compound citrate is converted to the four-carbon compound oxaloacetate.

2. What is substrate-level phosphorylation?
It occurs during glycolysis and the Krebs Cycle and is a precursor for the phosphorylation of glucose. SLP is also the source for the majority of the ATP produced in aerobic respiration.

3. What are the products of Kreb's? Glycolysis?
Kreb's - 6 NADH+H, 2 FADH2, 2 ATP, 4 CO2
Glycolysis - 2NADH, water, net gain of 2 ATP