Mitochondria Essay, Research Paper
Mitochondria are the cells power sources of the cell. They are distinct organelles with two membranes. Usually they are rod-shaped, however they can be round. The mitochondria are organelles enclosed in a double membrane of phosphoglycerides. Between the two membranes of the mitochondrion lies a region known as the intermediate space. The inner membrane is folded inward, producing what is known as cristae. These folds increase surface area, and enclose the mitochondria matrix. There are enzymes located in the inner membrane that are associated with cellular respiration. The outer membrane of the mitochondria contains the protein “porin”. This forms an aqueous channel through which proteins up to 10,000 daltons can pass and go into the intermembrane space. However, they cannot get into the matrix unless they pass through the inner membrane. This membrane contains cardiolipin which renders it virtually impermeable. This requires transport mechanisms across the membrane that are more organized and regulated. 2 The function of the mitochondria is that they are the main sites for the final stages of cellular respiration. The proteins that produce ATP are embedded in the inner membrane. The inner membrane of the mitochondrion has a large surface due to the cristae. This characteristic allows for increased productivity of the cellular respiration process. Mitochondria also have their own DNA and ribosomes. Ribosomes are organelles consisting of two subunits, one large, the other small. The subunits are made in the nucleolus from RNA and proteins. These two parts are fused together when they attach to mRNA. Their purpose is to synthesize proteins. Once the two subunits are joined by the mRNA from the nucleus, the ribosome begins to translate the mRNA into a specific sequence of amino acids, a polypeptide chain. There are two main types of ribosomes, free and bound. Free ribosomes are located in the cytosol and produce proteins for use within the actual cytoplasm. Bound ribosomes are located on the outer surface of the endoplasmic reticulum and produce proteins for use by the cell’s membranes. They also produce proteins for export from the cell. The mitochondria are located in the cytoplasm of the cell, and have the ability to move around the cell. They can also divide in two. The number of mitochondria within a cell will vary with the cell’s metabolic activity. The replication of mitochondria is a complex process. It all starts by the duplication or replication process. During this process the DNA inside the mitochondria replicate and go to separate ends of the mitochondria. The mitochondria then splits and two daughter cells are formed. Mitochondria have some of their own DNA, ribosomes, and can make 90 of their own proteins. The nucleus encodes the remaining proteins. Most of the lipid is imported though. Finally after the mitochondria die the endoplasmic reticulum wraps itself around the mitochondria and allows the Golgi Complex to takes hydrolases out by using acid. The hydrolases are recycled in the Golgi Complex and used to form a new lysosome.
Mitochondria are the powerhouses of the animal cell, where the products of the enzymatic breakdown, or metabolism, of nutrients such as glucose are converted into energy in the form of the molecule adenosine triphosphate (ATP). This process uses up oxygen and is called aerobic respiration. Plants possess, in addition to mitochondria, similar organelles called chloroplasts. 4The chloroplast has three membranes: inner, outer, and thylakoid. It has three compartments: stroma, thylakoid space, and inter-membrane space. These compartments and the membranes that separate them serve to isolate different aspects of photosynthesis. Dark reactions take place in the stroma. Light reactions take place on the thylakoid membranes. Each chloroplast contains chlorophyll, which is used to convert light energy from the sun into ATP. The chloroplast is the organelle of photosynthesis. In many ways, the chloroplast resembles the mitochondria. · Both are surrounded by a double membrane with an intermembrane space. · Both have their own DNA. · Both are involved in energy metabolism. · Both have membrane reticulations filling their inner space to increase the surface area on which reactions with membrane-bound proteins can take place. Photosynthesis is the process by which chlorophyll-containing organisms green plants, algae, and some bacteria capture energy in the form of light and convert it to chemical energy. Virtually all the energy available for life in the earth’s biosphere the zone in which life can exist is made available through photosynthesis.1An unbalanced chemical equation for photosynthesis is:CO2 + 2H2A + light energy x (CH2) + H2O + H2AMitochondria produce ATP and when they increase in size and number as a result of aerobic training, exercise can be prolonged for a much greater period of time than in an untrained state. Changes in the mitochondria only occur in trained muscles. That results in the absolute specificity of endurance training within an activity. This phenomenon does not support any form of cross-training or transfer of any other form of training effects that result from other forms of aerobic work. Enzymatic increases that occur within the mitochondria as a result of aerobic endurance training are as follows: 1) those associated with the Kreb’s cycle and respiratory chain; 2) those associated with the shuttle systems that transfer protons developed through glycolysis into the mitochondria for use in the respiratory chain; and 3) those associated with fatty acid metabolism (by 200 to 400 %). This feature is important because it permits the body to use more available fats for energy production, that is, more fat is extracted from normal blood to fuel exercise. 3 The mitochondria are the power-houses of the cell. Without the mitochondria, the cell would not be able to function properly. Without cells the body couldn t work and you wouldn t be able to exist. This just proves how vital the mitochondria are for everyday life.
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