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    The energy in glucose is transformed into ATP

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    What energy transformations occur between glucose and ATP? The energy in glucose is transformed into the energy stored in the chemical bonds of ATP by the oxidation of glucose during three steps of (aerobic) cellular respiration: 1) Glycolysis, 2) The Kreb's Cycle(also called the Citric Acid Cycle or the Tricarboxycyclic Acid Cycle , and 3) Oxidative Phosphorylation in the Cytochrome System.

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    The energy in glucose is transformed into the energy stored in the chemical bonds of ATP by the oxidation of glucose during three steps of (aerobic) cellular respiration: 1) Glycolysis, 2) The Kreb's Cycle(also called the Citric Acid Cycle or the Tricarboxycyclic Acid Cycle , and 3) Oxidative Phosphorylation in the Cytochrome System.
    In glycolysis, glucose is broken down into 2 pyruvic acid (pyruvate) molecules with two hydrogens being removed from the glucose molecule. This oxidation occurs in the cytoplasm of the cell and requires 2 ATP molecules, but yields a net +2 ATP's. The hydrogens removed from the glucose are later utilized in the cytochrome system:
    Glucose + 2 NAD+ + 2 Pi + 2 ADP → 2 pyruvate + 2 NADH + 2 ATP + 2 H+ + 2 H2O
    2 NADH yields 6 ATP (3 ATP per NADH) in oxidative phosphorylation (below)
    The Kreb's Cycle occurs in the mitochondria of the cell. Before the Kreb's Cycle can act on the products of glycolysis, the pyruvic acid molecules from glycolysis diffuse into the mitochondria of the cell and undergo further aerobic respiration transformations. Pyruvate is first oxidized to acetyl-CoA and CO2 by the Pyruvate dehydrogenase complex (PDC) in the mitochondria with one NADH molecule being formed in the process. The 2 acetyl-CoA molecules (from 1 glucose) are then oxidized to CO2 and H2O in the Kreb's Cycle with NAD being reduced to NADH which is utilized in oxidative phosphorylation to form more ATP.
    There are 8 steps in the Kreb's Cycle with a net energy produced each cycle of 3 NADH, 1 FADH2, and 1 GTP. The GTP can be utilized to produce another ATP. Two pyruvate molecules (one glucose molecule) yield 6 NADH, 2 FADH2, and 2 ATP.
    2 ATP from substrate-level phosphorylation
    6 NADH yields 18 ATP (3 ATP per NADH) by oxidative phosphorylation
    2 FADH2 yields 4 ATP (2 ATP per FADH2) by oxidative phosphorylation
    Oxidative Phosphorylation occurs in the cristae of the mitochondria via the electron transport chain or cytochrome system. Hydrogens are "donated" by NADH molecules from the Kreb's Cycle from oxidizing the NADH. In this electron transport chain, the electrons from the Hydrogens move from an electron donor (NADH) to the terminal electron acceptor (O2) in a progression of redox reactions, producing H20 and ATP. ATP is synthesized when the chemiosmotic or proton gradient is created across the inner mitochondrial membrane by the transfer of H+ (protons) in the electron transport chain. This is used to drive the oxidative phosphorylation of ADP producing ATP. The electrons are eventually transferred to O2 where two protons are added and water is formed.
    In eukaryotic cells, the theoretical maximum yield of ATP generated per glucose is 36 to 38. This depends on the 2 NADH from glycolysis entering the mitochondria and if the resulting yield is 2 or 3 ATP per NADH.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    © BrainMass Inc. brainmass.com December 24, 2021, 10:01 pm ad1c9bdddf>
    https://brainmass.com/biology/biological-chemistry/energy-glucose-transformed-into-atp-434829

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