Describe the process by which food energy is converted into the chemical energy of ATP in living cells. Go through each of the major steps in the process, including the starting and ending product of each step, and any important molecules produced or consumed. Include one or more labeled diagrams to help explain your answer.© BrainMass Inc. brainmass.com December 20, 2018, 6:01 am ad1c9bdddf
I hope this explanation helps you to better understand the topic.
So, to start with the conversion of food energy into chemical energy of ATP is called cellular respiration. This is an aerobic process (oxygen is required to complete the entire sequence). Without oxygen, the breakdown of the food molecules is incomplete and the cell does not make as much ATP molecules as it would if oxygen were present.
Okay, so the food particles, by this time broken down into monomers or polymers by the process of digestion, are taken up by the cell. Different types of molecules (proteins, lipids, nucleic acids, carbohydrates) are introduced into the sequence at different times, but the molecule that is used as the "example" for cellular respiration is often glucose (a monosaccharide [component of polysacchariades, aka carbohydrates]), so we'll use that for now.
A glucose molecule begins to be broken down in the cytoplasm of the cell in the process known as glycolysis (literal meaning, breaking down (or apart) a sugar). During glycolysis the glucose is broken down in a series of steps to form two molecules of pyruvate (also known as pyruvic acid). During glycolysis, two ATP actually have to be used to catalyze the change from glucose to glucose-6-phosphate, and from fructose-6-phosphate to fructose-1,6-bisphosphate. This puts the cell two ATP behind to begin with. Later on in the process one of the intermediates (glyceraldehyde-3-phosphate) is oxidized and an energy-carrier molecule known as NAD+ (important later on!!!) is reduced (reduction means the molecule has taken on a hydrogen ion [H+] and an electron) to ...
In this solution, I discuss the details of how the energy in the bonds of food molecules is released through the process of cellular respiration. Diagrams included in separate file.