Cell Respiration - Luis
Redox reactions
Phosphorylation
Oxidation
Reduction
Loss of electrons from a substance.
Gain of electrons from a substance.
Glycolysis
Addition of a phosphate group to a molecule.
Makes the molecules less stable.
Happens in the cytoplasm.
Results in a small net gain of ATP (2) without the use of oxygen.
Breaks down a glucose into 2 pyruvate.
Link reaction
It links glycolysis to the Krebs cycle.
Pyruvate is converted into Acetyl CoA (2C)
Happens in the matrix of mitochondrion.
Pyruvate is decarboxylated, as CO2 and forms an acetyl group.
The acetyl group is then oxidized, NAD+ is reduced forming NADH.
Acetyl group combines with coenzyme A, which enters the Krebs cycle.
It produces 2 molecules of acetyl CoA (2C), 2 CO2, and 2 NADH.
The Krebs cycle
Acetyl (Acetyl CoA) combines with oxaloacetate (4C) forming citrate (6C).
Citrate's oxidized and loses 1C as CO2. (5C compound). NAD+ is reduced, forming NADH.
5C compound's oxidized losing 1C as CO2. Again, NAD+ is reduced, forming NADH.
As a series of reactions occur, the 4C compound results in the formation of 4C compound oxaloacetate. As this happens, NADH, FADH2, and ATP are produced (one of each).
Products for each glucose molecule: 2 ATPs, 6 NADH, 2 FADH2, and 4 CO2.
Oxidative Phosphorylation
Glucose is phosphorylated through the use of 2 ATP, making it unstable.
The phosphorylated molecule is broken down into 2 3C sugars, called G3P.
The 2 G3P ---> pyruvate (3C). 2 NAD+ are reduced forming NADH. 4 ATPs are formed from 4 ADPs. The phosphate groups are used to re phosphorylate ADP to form ATP.
2 NADH are produced, and the net gain of ATP is 2.
Oxygen present = pyruvate transported to mitochondria. No oxygen = pyruvate is converted into lactic acid.
Phosphorylating ADP into ATP
NADH + FADH2 are oxidized by O2.
Electron transport chain
Chemiosmosis
Energy from initial glucose molecule is in ATP and mostly stored in NADH and FADH2
Transfer through the elctron carriers
ETC is located at the cristae
Electron at the end will be accepted by oxygen
Energy from electron carriers are used to transfer protons (H+) across inner membrane from the membrane to the inter membrane space.
32 net gain of ATP
Inner mitochondrial membrane
As protons are moved from the matrix to the intermembrane, creating a proton gradient.
Movement back to matrix via the enzyme ATP synthase, which allows ADP to be phosphorylated.