Cellular Respiration

Objectives: Describe the events that occur during respiration Explain the two stages of respiration and where they occur List the reactants and products in the respiration equation

What is Cellular Respiration? Respiration is the process by which cells obtain energy from glucose. Cells break down simple food molecules (sugar) and release the energy they contain. Cellular Respiration is very different than the life process called Respiration, which “breathing”.

How Does Cellular Respiration Work? CR takes place in 2 stages. The first stage takes place in the cytoplasm, and molecules of glucose are broken down (no oxygen is used, little energy is released ). The second stage occurs in the Mitochondria. Small molecules are broken down into even smaller molecules (needs oxygen, large amounts of energy released). Energy is released at both stages.

What is the Equation for Cellular Respiration? C6H12O6 + O2-----> CO2 + H2O + Energy(ATP) Glucose+Oxygen -----> Carbon Dioxide+Water+Energy

Photosynthesis vs. Cellular Respiration Both involve the same chemical compounds, but are the reverse processes. CR produces CO2, while Photosynthesis uses up CO2 in the atmosphere. CR uses O2, but Photosynthesis produces it. Photosynthesis requires energy from the sun, Cellular respiration gets energy from breaking down the chemical bonds in sugar molecules.

Fermentation Objectives: Compare & contrast fermentation vs. respiration (what are the differences?) Identify the two types of fermentation and the products of each

What is Fermentation? Some cells are able to obtain energy from food w/o using oxygen. These organisms (single-celled, don’t need oxygen) obtain their energy through the process of Fermentation. Fermentation does not give off as much energy as Cellular Respiration.

Organisms that use fermentation anaerobic organisms (some types of bacteria and fungus) found in the gastrointestinal tract (e-coli) found in the ground (tetanus) yeast

Two Types of Fermentation Alcoholic & Lactic Acid Fermentations Alcohol - yeast, a fungus, converts sugars into alcohol, carbon dioxide & releases energy Bakers and Brewers use this in making bread rise and fizz/bubbles in beer Yeast vs. Amount of Sugar Lab on YouTube: http://www.youtube.com/watch?v=PLG_bsJseCU Lactic Acid - muscles without enough Oxygen convert sugars into lactic acid to release the needed energy for contractions. This happens when you run or exercise hard, lactic acid builds up in your muscles and gives them that sore feeling