Chemistry 104

Lecture #15b: Carbohydrate Metabolism (at the molecular level)

Read: pg. 685-710

HW: pg. 701 (29, 30, 39, 46); pg. 720 (10, 11, 15)

AND answer the following:

  1. Refer to Figure 24.12 and select the reactions in which the following processes occur (expenditure of phosphate bond energy, formation of high-energy phosphate bond, a redox reaction)
  2. Refer to Figure 25.1 and identify all redox reactions. Indicate what is oxidized and what is reduced.

!!Book Test (50 pts) March 21!!

Objectives:
  1. Explain the role of combustion (oxidation) in carbohydrate metabolism. Know that the products of carbohydrate metabolism are CO2 and H2O.

    2. What happens when the system fails?

  2. Be able to identify all functional groups in glycolysis and the Kreb’s cycle (also known as the TCA or tricarboxylic acid) cycle.
  3. Identify redox reactions in glycolysis and the Kreb’s cycle. What is oxidized and what is reduced?
  4. Know in which parts of the cell glycolysis, the Kreb’s cycle and oxidative phosphorylation occur.
  5. Explain the role of enzymes as catalysts in carbohydrate metabolism. Give an example of 1 key regulatory enzyme.
  6. Know that the Embden-Meyerhof pathway (also considered the first part of glycolysis in many texts) converts 1 mole of glucose to 2 moles of pyruvate
  7. Know that the Kreb’s cycle (alias TCA cycle and citric acid cycle) accepts 2 carbons from acetyl CoA which combine with oxaloacetic acid to form citric acid. The Krebs cycle generates reduced coenzymes (NADH and FADH2) that carry e- to the electron transport chain and regenerates oxaloacetic acid. Each cycle spits out 2 molecules of CO2.
  8. Know that the electron transport chain transfers electrons in a series of redox reactions that produces a separation of charge across the inner mitochondrial membrane. Ultimately the electron transport chain transfers electrons to O2 which is then reduced to H2O.
  9. Know that oxidative phosphorylation synthesizes ATP from ADP. It is driven by the separation of charge across the inner mitochondrial membrane.