“In this lesson, we will review cellular respiration and explore a distinct, important part of its process: glycolysis. We will also cover the role of enzymes, ATP, and oxygen in glycolysis.
What is Cellular Respiration?
Imagine you're visiting a beach town and plan on walking the boardwalk, playing arcade games, eating funnel cake and ice cream and riding the ferris wheel. It's a cash-only boardwalk and you need change for the $100 bill you brought with you on vacation. The cash register, bank or bill vending machine you change the $100 bill at is like cellular respiration. Sound crazy? Keep following the story.
Let's say you get change from the local bank on the boardwalk. The bank gives you two $20 bills, four $10 bills, two $5 bills and ten $1 bills. The money you get back from the bank is energy (we will define what that energy is shortly). Now that you have the change (energy) you need to do all the fun things you want on the boardwalk, you meet back up with your family and the rest is history.
Back to Science
Cellular respiration is the process by which your body converts biochemical energy from nutrients in the food you consume into energy that's usable by the body. It's the broad term that describes the set of metabolic reactions and processes that occur in the body that allow us to utilize food as an energy source.
Cellular respiration was the bank in our example because it took one large bill and broke it down into smaller bills, which were used for different activities. Cellular respiration oxidizes food into energy in the form of ATP, adenosine triphosphate. ATP in our example was the change given to us by the bank. ATP is used as energy at the cellular level in our bodies.
NADH is also a form of cellular energy, and while it's not as important in our lesson as ATP is, it is still a byproduct of cellular respiration. NADH stands for nicotinamide adenine dinucleotide, but you can just remember it as NADH for now.
Glycolysis
Glycolysis is one of the main processes involved in cellular respiration. Glycolysis is the pathway that converts sugar into energy, or glucose (C6H12O6) into pyruvate (CH3COCOO), generating ATP during the conversion.
An important term to know is catabolism. Catabolism is the breaking down of larger molecules into smaller ones (conversely, anabolism is the building of larger molecules from smaller ones). Glycolysis is catabolic; it breaks down glucose, a 6 carbon sugar into pyruvate, a 3 carbon sugar. The truth is in the name: glyco for glucose, and lysis, Greek for 'to unbind'. Glycolysis literally means 'breaking down glucose'.
Glycolysis occurs in the cytosol of the cell: the cytosol is the fluid component of the cytoplasm, the area inside a cell's membrane which contains the organelles. Glycolysis does not need oxygen to occur; it is completely independent of molecular oxygen and can proceed without it. However the energy byproducts, ATP and NADH, do require oxygen to be utilized.
Glycolysis is unique because it is completely anaerobic - meaning it doesn't require oxygen and will proceed with or without it. Unlike the next steps in cellular respiration, which absolutely require oxygen to occur.
Let's review. Glycolysis breaks down glucose into pyruvate, and the byproducts of this reaction include ATP and NADH, which are used as energy sources by our bodies. This reaction is oxygen-independent and occurs in the cytosol of our cells.
Steps
There are a series of ten reactions that occur in a single 'round' of glycolysis (i.e., one molecule of glucose), and three unique stages.
Each reaction is catalyzed by a specific enzyme. An enzyme is a protein that speeds up a chemical reaction and essentially allows it to occur. In the image, the specific enzymes are noted in blue.” I hope this helps you for what your looking for.
