Cell Energy Worksheet
Answer the following questions:
Cellular respiration:
• What is cellular respiration and what are its three stages?
A living version of internal combustion-is the main way that chemical energy is harvested from food and converted to ATP energy, it is also called an aerobic process, which is just another way of saying that it requires oxygen. So cellular respiration is defined as the aerobic harvesting of chemical energy from organic fuel molecules. The three stages are; glycolysis, the citric acid cycle, and the electron transport.
• What is the role of glycolysis? Include the reactants and the products. Where does it occur?
The word itself means “splitting sugar”. That is what happens during glycolysis, a six-carbon glucose molecule is broken in half, forming two three-carbon molecules it requires two ATP molecules per glucose. The three-carbon molecules then donate high-energy electrons to NAD+ the electron carrier, forming NADH. In addition to NADH, glycolysis also makes four ATP molecules directly when enzymes transfer phosphate.
• What is the role of the citric acid cycle? Include the reactants and the products. Where does it occur?
This cycle also called the “Krebs cycle”, completes the breakdown of glucose all the way to CO2, one of the waste products off cellular respiration. The enzymes for the citric acid cycle are dissolved in the fluid within mitochondria. Glycolysis and the citric acid cycle generate a small amount of ATP directly. They generate much more ATP indirectly, via redox reactions that transfer electrons from fuel molecules to NAD+, forming NADH.
• What is the role of the electron transport system? Include the reactants and the products. Where does it occur?
The proteins and other molecules that make up electron transport chains are embedded within the inner membrane of the mitochondria.