Biology

BIOLOGY
11/3/07

PHASES OF CELLULAR RESPIRATION

    There are four phases of complete glucose break down which are glycolysis, preparation reaction, citric acid cycle, and the electron transport chain.   Below is a breakdown on what happens through each process.

    Glycolysis – (Inputs) Glucose takes place within the cytoplasm outside the mitochondria, is the break down of glucose to two pyruvate molecules.   As glycolysis begins, two ATP are used to activate glucose, a c6 molecule that splits into tow C3 molecules knows as G3P.   Each G3P has a phosphate group.   Oxidation of G3P now occurs by the removal of electrons, which are accompanied by hydrogen ions.   Through this process, the following occurs.
    2NAD+ plus 4H     2NADH plus 2H+
When the NADH molecule passes 2 electrons on to another carrier, they become NAD+ again.   The oxidation of G3P will synthesize for ATP. This is substrate-level phosphorylatin.   There is a subtraction of the two ATP that were used to get started, and there is a net gain of two ATP from glycolysis.   Inputs and outputs of glycolysis are as follows:
          Input                                                                     Outputs

  Glucose 2 Pyruvate
  2 NAD+                                                             2 NADH
  2 ATP                                                                         2 ADP
  4 ADP plus 4 P                                                           4 ATP Total
                                                                                  2 ATP Net Gain

Preparation Reaction – Pyruvate is converted to a 2-carbon where oxidation occurs.   Through the oxidation occurs.   Through the oxidation process, electrons are removed from pyruvate by NAD+, and H+.   This reaction occurs twice per glucose molecule.

      2 pyruvate plus 2 CoA             2 Acctyl CoA + 2 carbon dioxide.

Citric Acid Cycle – The Citric Acid Cycle is located in the matrix of the mitochondria,...