In some cases, loss of muscular strength including that of the heart muscle and loss of nerve function with age have been proposed to result from populations of mitochondria that have been crippled by such mutations in nerve and muscle tissue, which perform high rates of aerobic respiration.
When generated outside mitochondria, toxic forms of oxygen can cause mutations in genes of the nucleus that lead to uncontrolled cell division cancer. Toxic oxygen can be made from water by ionizing radiation and it is thought that the carcinogenic effect of ionizing radiation is mediated by the toxic oxygen it forms.
To limit the harm that can be caused by toxic forms of oxygen, your cells have "antioxidants" that convert them back into harmless O 2 or water. Some of these antioxidants are enzymes and others are not. Plant cells have high levels of antioxidants, since photosynthesis generates toxic forms of oxygen.
You acquire some of these antioxidants when you eat plant cells. In some cases, they act as antioxidants in your cells too.
Vitamin C, Vitamin E, and the precursor to Vitamin A are all antioxidant compounds that you need in your diet. Vitamin C is mostly needed to maintain connective tissues while Vitamin A is mostly needed by the light-sensitive cells in the back of your eye. Both Vitamin A and C may also act as antioxidants in your cells, however. Vitamin E is an effective antioxidant in your cells and those of plants. You can gain whatever antioxidant benefits these compounds provide by including plenty of fresh fruits and vegetables in your diet.
You can also get them from supplements vitamin pills but take care. Both Vitamin A and E are toxic at high dosages. Now that you understand how cells get energy from the sun photosynthesis by green plant cells or from food non-photosynthetic cells, including yours , let's discuss energy flow through a multi-celled organism, which is an assemblage of many cells working together.
Let's use your body as an example. In a multi-celled organism, cells are organized into tissues. Tissue are combined into organs and organs cooperate in "organ systems". One of these is the digestive system of your body. The digestive system includes the digestive tract, a pathway through your body that is taken by the food you eat.
The digestive tract includes mouth, esophagus, stomach, and intestines small and large. The liver and pancreas are part of the digestive system also. If, the osmotic pressure of the external solution is more than the osmotic pressure of the cytoplasm, the external solution is called. If, osmotic pressure of the external solution is equivalent to the osmotic pressure of the cytoplasm, then the external solution is called as.
Osmosis can be defined as the process in which. Pure water at standard temperature, not under any pressure will have the water potential. The greatest water potential is that of. A large central vacuole is present in. In terms of water movement, the plant cell wall is. For plant growth and productivity, the factor, which often falls in the category of limiting factors, is.
Oxygen is the final electron acceptor at the end of the electron transport chain of aerobic respiration. In the absence of oxygen, only a few ATP are produced from glucose. In the presence of oxygen, many more ATP are made. However, some anaerobic organisms that evolved before the atmosphere contained oxygen have survived to the present.
Therefore, anaerobic respiration , which takes place without oxygen, must also have advantages. A major advantage of aerobic respiration is the amount of energy it releases. Without oxygen, organisms can split glucose into just two molecules of pyruvate. This releases only enough energy to make two ATP molecules.
With oxygen, organisms can break down glucose all the way to carbon dioxide. This releases enough energy to produce up to 38 ATP molecules. Thus, aerobic respiration releases much more energy than anaerobic respiration. The amount of energy produced by aerobic respiration may explain why aerobic organisms came to dominate life on Earth.
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