Energy in food is stored as carbohydrates, proteins & fats. Before you can use that energy, it must be released and transferred to ATP.
Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen.Formula:C6H12O6 + 6O2 6CO2 + 6H2O + 34 ATP Glucose+ Oxygen CO2 + H2O + Energy
If cellular respiration took place in just one step, all energy would be released at once and our cells need to control this.
Pyruvate PyruvateC3 C3
2 ADP + 2NAP+ 2 ATP + 2NADH
Takes place in the cytoplasmNet gain of 2 ATPTakes place without oxygen (anaerobic)NADH is formed (electron carrier)Interesting Fact:Since bacteria dont have any membrane-bound organelles such as mitochondrion, they can only produce ATP by glycolysis!
1. Anaerobic Respiration - If no oxygen is present, pyruvate goes through a process called fermentation.
2. Aerobic Respiration If oxygen is present, pyruvate enters the mitochondria and enters the Krebs Cycle.
Whats the difference?
2. Krebs Cycle A stage of aerobic (requires oxygen) respiration in which pyruvate is converted into CO2, water and ATP.~ Takes place in the mitochondria
The Krebs Cycle is a continuous cycle of electrons transferred to energy carriers. Citric acid is broken down, CO2 is released (you exhale it out), and ATP is released to be used in cellular activities.
What happens to all of the high energy electrons???Citric Acid
A protein in the membrane called ATP synthase. These enzymes convert ADP to ATP.34 ATP are produced (Lots of energy!)
In the absence of oxygen, glycolysis produces just 2 ATP molecules per glucose.
In the presence of oxygen, everything changes.The Krebs Cycle & electron transport chain allow the cell to produce 34 more ATP molecules.36 total ATP!
18 times as much can be generated from glucose in the presence of oxygen.The final waste products are water and carbon dioxide.
38% of the energy in glucose is used to make ATP. 62% is released as heat. (This is why you become warm when you exercise).
Photosynthesis & Cellular Respiration are almost opposite processes.Photosynthesis stores energyCellular Respiration releases energyWhat do you notice about the equations????
Whats the difference?
~ Takes place in the cytoplasmPyruvate
Alcohol Lactic Acid(plants) (animals)2 ATPCO2
Lactic acid is produced in your muscles during rapid exercise when the body cannot supply enough oxygen to the tissues.
The buildup of lactic acid causes a painfull burning sensation.