C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O+ energy (38 ATP) Glucose + Oxygen (REACTION) yields Carbon Dioxide + Water and the GOAL product of the reaction Adenosine Tri-phosphate CELLULAR RESPIRATION

So what is ATP? Defined: ATP is a ‘high energy compound found in cells that performs an important function in energy storage and transfer’. To GOAL of the process of Cellular Respiration is to produce ATP. Defined: ‘Cellular Respiration includes all the chemical reaction in which energy is released in support of cell life’.

The reactions that take place include the breaking down of glucose and other foods and the transfer or energy to ATP. The exact reactions and products vary from organism to organism, cell to cell, but the process of respiration is necessary to the life of every cell. It is the bonds that hold organic molecules together (ionic or covalent) that have the ‘energy’ found in the molecule. It is the breaking of these bonds that gives food its ‘energy’.

Ultimately, the energy in the molecule bonds is chemical, but it was first light energy and therefore first came from the sun! The sequence is: Sunlight was the energy that caused photosynthesis to take place resulting in the making of the glucose. Therefore the light energy was stored in the glucose. Therefore, when the chemical bonds in the glucose are broken, this chemical energy really originated with the sun.

How is the energy released? Oxidation: takes place when oxygen is either added to a molecule or hydrogen is removed from a molecule. Either way, electrons (- ) are removed from the substance being oxidized. Obviously, the process that ‘burns’ calories in your body, releasing the stored chemical energy in the glucose bonds has to be controlled! Imagine if that process was as powerful in your cells as what we saw in the test tube!

The answer is a controlled process called respiration The cells in your body get their energy by removing the hydrogen from the molecules in glucose. This is a complex process that takes place over many steps rather than all at once as seen in the gummy bear demonstration.

Each step of respiration in a cell is controlled by enzymes! As the energy is released the cell’s ‘batteries’ are re-charged by changing ADP (a enzyme compound found in cells that helps with energy storage and transfer)into ATP (a unit of useable energy that powers cell life). Glucose is the raw fuel used by most organisms to power this energy transformation.

Two stages of respiration Anaerobic Stage: First stage. This does NOT require oxygen! Happens outside the mitochondria. Up to 12 enzymes are used to cause a series of reaction. Glucose is broken down into two 3 carbon molecules called pyruvic acid. It ‘costs’ 2 ATP molecules to supply the ‘activation energy’ needed to do this process. (nothing is free, it ‘costs’ energy to make energy). The good news, is splitting the glucose molecule forms 4 ATP

RAD! NAD! Four Hydrogen atoms are ‘given off’ when pyruvic acid is made. These are joined to a coenzyme called nicotinamide adenine dinucleotide or NAD for short. NAD is a ‘hydrogen acceptor’. When NAD accepts the H, the resulting molecule is NADH 2. Energy released in the anaerobic stage is about 7% of the energy available in the glucose. The rest is transferred into the bond of the pyruvic acid molecule.

Aerobic Stage The second part of respiration is called the aerobic stage since it requires oxygen. Here, the newly formed pyruvic acid is broken down (thus releasing the remaining energy transferred from the glucose). Water and Carbon Dioxide are given off.

Remember, nothings Free…. It costs ATP (energy) to make ATP (energy)…. When H combines with O to make water it is an explosive force. This wouldn’t be good inside a cell. In cells, H goes through a chain of reactions called the electron transport chain. Every electron that goes down the chain releases enough energy to change three low energy ADP’s into three high energy ATP’s.

For every molecule of glucose broken down by cellular respiration 36 ATP are produced. This combined with the 2 ATP from the first part of respiration means in the end 38 ATP are made during the entire process.

So where in a cell does this happen? In the Mitochondria, which is why it is called the ‘Power House’ of the cell.