Cellular Respiration

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”.

Two Types Of Cellular Respiration Anaerobic: does NOT require Oxygen –Takes place in the cytoplasm of cells –Not very efficient, glucose only partially broken down –Makes only 4 ATP –Examples: Alcohol Fermentation and Lactic Acid Fermentation –Takes place in certain anaerobic bacteria

Two Types Of Cellular Respiration Aerobic Respiration: –Takes place in the Mitochondria of cells –Efficient, glucose is completely broken down –Makes 36 ATP –Takes place 24/7 in most organisms

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 (anaerobic-no oxygen used). The second stage occurs in the Mitochondria, and there, small molecules are broken down into even smaller molecules (aerobic- needs oxygen). Energy is released at both stages.

What is the Equation for Cellular Respiration? C 6 H 12 O 6 + O > CO 2 + H 2 O + Energy(ATP) Glucose+Oxygen -----> Carbon Dioxide+Water+Energy

What is Fermentation? Some cells are able to obtain energy from food w/o using energy. 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.

Equation for Anaerobic Cellular Respiration Glucose  Alcohol + Carbon Dioxide + ATP Glucose  Lactic Acid + ATP Only 4 ATP are produced during anaerobic respiration

Uses for Anaerobic Cellular Respiration Found in muscle cells during high intensity exercises (Lactic Acid) Used to make alcohol (beer, wine, whiskey), bread, yogurt and pickles Used during digestion in animals

Photosynthesis vs. Cellular Respiration Both involve the same chemical compounds, but are the reverse processes. CR produces CO 2, while Photosynthesis uses up CO 2 in the atmosphere. CR uses O 2, but Photosynthesis produces it. Photosynthesis requires energy from the sun, Cellular respiration gets energy from breaking down the chemical bonds in sugar molecules.

Photosynthesis vs. Cellular Respiration