Bio Test 3 Chp 9

a partial degradation of sugars or other organic fuel that occurs without the use of oxygen

oxygenis consumed as a reactant along with the organic fuel

Organic compounds + Oxygen -> Carbon dioxide + Water + Energy

Some prokaryotes use substances other than oxygen as reactants in a similar process that harvests chemical energy without oxygen

C6H12O6 + 6O2 ->6 CO2 + 6 H2O + Energy (ATP +heat)

• breakdown of glucose is exergonic, having a free energy change of -686 kcal (2,870 kJ) per mole of glucose decomposed (ΔG=-686 kcal/mol).
• 34% of the potential chemical energy in glucose has beentransferred to ATP

transfer of one or more electrons (e-) from one reactant to another

the loss of electronsfrom one substance

• reducing agent - electron donor
• oxidizing agent - electron acceptor

the addition of electrons to another substance

• an electron carrier, a coenzyme, an electron carrier because it can cycle easily between oxidized (NAD+) and reduced (NADH) states
• a single molecule of NADH generates enough proton-motive force for the synthesis of 2.5 ATP
• FADH -> 1.5 ATP

The enzymatictransfer of 2 electrons and 1 proton (H+) from an organic molecule in food to NAD+ reduces the NAD+ to NADH

• Glycosis
• Citric acid cycle and pyruate oxidation
• Oxidative phophorylation : electron transport and chemiosmosis

• a series of chemical reactions in the cytoplasm of a cell that breaks down glucose into two molecules of pyruvic acid
• 4 atp produced, 2 atp used, 2 net ATP, 2 NADH molecules are produced.
• Intermediate Stage -  eukaryotes, pyruvate enters the mitochondrion combine with coenzyme A and is oxidized to a compound called acetyl CoA
• Glycolysis occurs whether or not O2 is present

• Glucose
• 2 ADP + 2 P <- 2 ATP used  (energy investment)
• 4 ADP + 4P -> 4ATP formed
• (2NAD+)   +   (4e)-  +  (4H+) -> (2NADH) + (2H+)
• Net : 2 pyruvate + 2H2O,   2 ATP,  2NADH + 2H+

• Upon entering the mitochondrion via active transport, pyruvateis first converted to a compound called acetyl coenzyme
• 1) Pyruvate oxidized -> CO2
• 2)Form acetate, oxidized e- convert NAD+ -> NADH
• 3)acetate(pyruate acid) + CoA -> acetyl CoA 

• A series of reaction that breaks down Acetyl-CoA to form 2 ATP, 3 NADH, 1 FADH2
• CO2 is by product 
• similar to Calvin Cycle

[Acetyl CoA] -> [Citrate (6 CO2)] -> [NAD+ -> NADH + H]  -> [Ketogutaric acid (4CO2)] -> [ADP ->ATP] +  [NAD+ -> NADH + H] -> [Succinic Acid] -> [FAD -> FADH2] + [NAD+ -> NADH + H] -> Oxaloacetic Acid

• Step 3,4,8 -> 3 NAD+ produced
• Step 6 -> FADH2 produced
• Step 5 -> ATP produced by substrate-level phosphorylation.

The energy released at each step of the chain is stored in a form the mitochondrion (or prokaryotic cell) can use to make ATP from ADP

Electron transport chain + Chemiosmosis

A smaller amount of ATP is formed directly in a few reactions of glycolysis and the citric acid cycle by a mechanism

proteins, built into the inner membrane of the mitochondria of eukaryotic cells and the plasma membrane of aerobically respiring prokaryotes.NADH to the “top,” higher-energy end of thechain. At the “bottom,” lower-energy end, O2 captures these electrons along with hydrogen nuclei (H), forming water.glucose → NADH →electron transport chain → oxygenDownhill -> become oxidized FADH2 and NADH carry electrons to chain O2 binds with H to form H2O -> releasing 32 or 30 ATP! (36?)

• 1)Electrons removed from glucose by NAD, during glycolysis and thecitric acid cycle, are transferred from NADH to the first moleculeof the electron transport chain
• 2) a small hydrophobic molecule, the only memberof the electron transport chain that is not a protein. (CoQ)

• Most of the remaining electron carriers between ubiquinone and oxygen are proteins
• heme group
• 2) very electronegative.Each oxygen atom also picks up a pair of hydrogen ions fromthe aqueous solution, forming water.

• the enzyme that actually makes ATP from ADP and inorganic phosphate
• smallest molecular rotary motor known
• proton motive force, emphasizing the capacity of the gradient toperform work.
• consists of a number of polypeptide subunits
• drive by chemiomosis

energy stored in the form of a hydrogen ion gradient across a membrane is used to drive cellular work such as the synthesisof ATP

• “sulfate-reducing” marine bacteria, for instance,use the sulfate ion (SO42) at the end of their respiratorychain instead of oxygen
• the final acceptoris another molecule that is electronegative
• Has ETC(cellular respiratory)

• a process follows Glycolysis when oxygen is present
• transfer electrons from NADH to pyruvate, the end product of glycolysis.
• no ETC
• Final electron acceptor is organic molecule like pyruvate(lactic)/acetaldehyde(alcohol)
• -Lactic acid fermentation
• -Alcoholic fermentation

• pyruvate is converted to ethanol (ethyl alcohol) in two steps
• Pyruvate -> CO2 -> Acetaldehyde(2carbon) -> enthanol by NADH
• produce CO2 and Ethy alcohol, 2ATP
• used by yeast cells
• brewing, winemaking, and baking

• pyruvateis reduced directly by NADH to form lactate as an endproduct, with no release of CO2.
• -human muscle cells make ATP

carry outonly fermentation or anaerobic respiration.

organism, like yeasts and many bacteria, can make enough ATP to surviveusing either fermentation or respiration

• Proteins -> Amino acids -> Glycolysis(Pyruvate)
• Carbohydrates -> sugars -> Glycolysis(Glucose)
• Fats-> Glycerol ->Glycolysis(Glyceraldhyde-3)
•        -> fatty acids (beta oxidation)-> Acetyl Coa
• Fat produce twice as energy as Carb.

breaks the fatty acids down to two-carbon fragments, which enterthe citric acid cycle as acetyl CoA.

• Metabolism is versatile and adaptable
• compounds formed as intermediate stage can be diverted to anabolic pathways which cell can synthesize the molecules it required.

• adjuststhe rate of respiration as the cell’s catabolic and anabolic demands change.
• the enzyme that catalyzes step 3 of glycolysis
• inhibited by ATP(accumulated)  and stimulated by AMP -> slow down glycolysis
• citrate accumulates in mitochondria, some of it passes into the cytosoland inhibits phosphofructokinase.