Cellular Respiration
Whether an organism produces its own food or consumes food, ultimately, the food is broken down to release its energy that is then converted into a usable form of energy by cells. This usable form of energy is ATP.
Cellular Respiration is the process of converting energy found in food into ATP which is easily used by cells for many processes. ATP is short for adenosine triphosphate.
Respiration that takes place in the presence of oxygen is called aerobic respiration and it yields a large amount of ATP. Aerobic respiration takes place in the mitochondria. Aerobic respiration is often called cellular respiration. Cellular respiration consists of two steps: 1. The Kreb Cycle and 2.The Electron Transport Chain. The formula for cellular respiration is given below.
C6H12O6 + 6O2 → 6CO2 + 6H2O + 36ATP
Respiration that takes place in the absence of oxygen is anaerobic respiration. Anaerobic respiration generates much less energy than aerobic respiration. Anaerobic respiration takes place in the cytoplasm. Organisms that have no oxygen or no mitochondria will perform anaerobic respiration. There are two types of anaerobic respiration:
1. Alcohol Fermentation: Glucose → Ethyl Alcohol + CO2 + 2 ATP
2. Latic Acid Fermentation: Glucose → Lactic Acid + 2 ATP
Both aerobic and anaerobic respiration begin with a process called glycolysis that takes one, six carbon glucose molecule and breaks it down into two, three carbon pyruvate molecules.
GLYCOLYSIS
Glucose → Pyruvate + Pyruvate
c-c-c-c-c-c → c-c-c + c-c-c
Once glycolysis is complete, the presence or absence of oxygen determines if the pyruvate will enter aerobic respiration or anaerobic respiration.
