Sci/230week3 Cell Energy

Associate Program Material

Cellular respiration:

• What is cellular respiration and what are its three stages?

Cellular respiration is the usage and complete cycle of glucose molecule using oxygen. (Eric J. Simon, Jane B. Reece, and Jean L. Dickey, 2010)

The three stages of cellular respiration are: glycolysis, Krebs cycle, and electron transport. (Eric J. Simon, Jane B. Reece, and Jean L. Dickey, 2010)

• What is the role of glycolysis? Include the reactants and the products. Where does it occur?

The role of the glycolysis stage is to split sugars of two molecules to form three carbon molecules. (Eric J. Simon, Jane B. Reece, and Jean L. Dickey, 2010) Then the three carbon molecules give electrons to the electron carrier to form NADH. (Eric J. Simon, Jane B. Reece, and Jean L. Dickey, 2010)

The glycolysis occurs in the cytosol.

• What is the role of the citric acid cycle? Include the reactants and the products. Where does it occur?

The role of the citric acid cycle occurs after the glycolysis stage. In the citric acid cycle several compounds (NAD and FAD) capable of storing "high energy" electrons are produced along with two ATP molecules. These compounds are reduced in the process. These reduced forms carry the "high energy" electrons to the next stage.(Regina L. Bailey,2012)

• What is the role of the electron transport system? Include the reactants and the products. Where does it occur?

An electron transport chain functions as a chemical machine that uses the energy released by the “fall” of electrons to pump hydrogen ions (H) across the inner mitochondrial membrane.

The energy stored by electron transport behaves something like the elevated reservoir of water behind a dam. There is a tendency for hydrogen ions to gush back to where they are less concentrated, just as there is a tendency for water to flow downhill. The inner membrane, analogous to the dam, temporarily restrains hydrogen ions. The energy of dammed...