What Is Cell Respiration

What is Cell Respiration? And what is Photosynthesis? And what, is there effect on our lives? In this paper I'll be discussing these topics and try to clear up any confusion on the subject. Did you know that with out even knowing it you are carrying on cell respiration millions of times a second? And that you can't live without it? But it is not only humans who do this. All living things, whether one cell or a trillion, plant or animal, human or otherwise, carry on the process of cell respiration. Now you may have herd that plants carry on photosynthesis, which is true, but they also carry on cell respiration. It would be really stupid if plants could make their own food, then not be able to use it. First I'll be talking about cell respiration process.

Cell respiration is the process of re-assembling ATP or Adenosine Tri-Phosphate. These are the little molecule groups composed of: A) Adenosine - which is a nitrogen containing molecule, B) Ribose - a five carbon sugar, and C) three Phosphate groups. The chemical energy is "put in" or contained in the bonds linking the Phosphate groups together during cell respiration. This energy comes from the food we eat, and cell respiration stores it in the form of ATP. Now this process takes place inside the Inner Membrane of the Mitochondria. When ATP is used, one of the Phosphate groups break off and a WOOSH of energy is radiated out. After this the ATP becomes Adenosine Di-Phosphate, or, a ATP less one Phosphate group.

All animals, including humans, are heterotrophs. This only means that we can't make our own food. We have to consume other living things to survive. Autotrophs, on the other hand, are plants which carry on Photosynthesis and make their own food. But we can't and need to eat and breathe to live. Everyone knows that, but what do we do with that food and Oxygen? The answer lies in cell respiration. When we consume food, one of the main ingredients that we need from it is Glucose. This is a complex molecule composed of C6H12O6 and is used with 6 O2 molecules to re-construct ATP molecules. When this process is completed 38 ATP's are re-constructed in various places inside your Mitochondria. Basically the WOOSH is reversed and turned into a sort of HSOOW which assembles the ATP's together again. This ATP in your body is what allows your cells to carry on life processes. It is the life blood of your cells and powers them to do everything that they have to do, save diffusion. It makes your cells function properly, and therefore, keeps your tissues and organs working well, so you don't die.

Now I will talk about Photosynthesis. This process is carried on only by Autotrophs, or plants. To plants, it is like eating on a cellular basis. It is what powers them to carry on cell respiration. So don't confuse the two. Photosynthesis doesn't re-construct the ATP's, it is what powers cell respiration to do so. In plant cells there is a special organelle belonging to the Plastid classification. It is called a Chloroplast and contains Chlorophyll. This is what gives plants their green color. The Chloroplast is formed by a bi-lipid membrane. Inside is a network of flattened sacs of photosynthetic membranes called Thylakoids. These Thylakoids have a internal reservoir called a lumen. The lumen contains water which is a main part of the photosynthetic process. The Thylakoids are arranged in stacks, called Grana, of up to several dozen. The Thylakoids are surrounded by a protein rich solution of Stroma. The Thylakoid is also formed from a bi-lipid membrane. Embedded in the membrane are packets of ATP synthetase which helps to catalyze the production of ATP molecules.

The reason plants are Green is because that is the light wavelength being reflected back, or the light that is not being used for Photosynthesis. The Blue, Red, Yellow, and just about any other color besides Green is being absorbed by the Chloroplasts and used to make energy. Why then, do deciduous trees turn color in the fall? Well, there are so many Chloroplasts in the leaves that it masks the Cartenoids which are present in most plants. These are the Red, Yellow, and Brown pigments we see in the fall. The two most common Cartenoids are Xanthophylls and Carotenes.

There are two parts to the Photosynthesis process. The Light Reactions and the Dark Reactions. The light reactions need light and are done in the Thylakoid. The dark reactions do not require light to be carried out, but do not need to be done in darkness. The light reactions are the main fuel for cell respiration, although cell respiration cannot occur with out the help of the dark reactions. The dark reactions create Glucose, or the plants equivalent to food. The light reactions set up a process called Chemiosmosis, which sets the stage for cell respiration.

It is inside the Thylakoids where the light reactions of Photosynthesis take place. A Photosystem is a unit of several hundred chlorophyll molecules and associated acceptor molecules. Light passes through the membrane and excites Photosystem 1. An Electron is excited and "jumps" off this Photosystem and travels down the Electron Transport Chain, or a path where the electrons "jump" molecule to molecule. The electron from Photosystem 1 reaches a NADP+