Miochondria And Chloroplasts

Scientists discovered that chloroplasts and mitochondria contain DNA similar to the DNA of certain bacteria, just as Margulis’s theory had predicted. Upon this data, Margulis extended her book and entitled it Symbiosis in Cell Evolution. Margulis then traveled, presenting and defending her theory, and her theory was becoming well accepted by her peers. “Margulis added that flagella and cilia (appendages and protuberances that many microbes use for motility) originated from spiral bacteria called spirochetes (Markov 10).” The second edition of her book, published in 1993, Margulis suggested that “symbiogenesis is a major factor in evolution, leading to the creation of new species via natural selection (Markov

When life arose on Earth about 4 billion years ago, the first types of cells to evolve were prokaryotic cells. For approximately 2 billion years, prokaryotic-type cells were the only form of life on Earth. The oldest known sedimentary rocks found in Greenland are about 3.8 billion years old. The oldest known fossils are prokaryotic cells, 3.5 billion years in age, found in Western Australia and South Africa. The nature of these fossils, and the chemical composition of the rocks in which they are found, indicates that these first cells made use of simple chemical reactions to produce energy for their metabolism and growth. Eukaryotic cells evolved into being between 1.5 and 2 billion years ago. Eukaryotic cells appear to have arisen from prokaryotic cells, specifically out of the archaea. Indeed, there are many similarities in molecular biology of contemporary archaea and eukaryotes. However, the origin of the eukaryotic organelles, specifically chloroplasts and mitochondria, is explained by evolutionary associations between primitive nucleated cells and certain respiratory and photosynthetic bacteria, which led to the development of these organelles and the associated explosion of eukaryotic diversity. Today Prokaryotes

A more recent evolutionist of the theory is Lynn Margulis, who is famous through her research career that mainly focused on this concept. It was Biologist Lynn Margulis from Boston University who in 1967 began to tell an older view. She suggested that certain prokaryotes had been overtaken by larger more active species. Instead of being digested inside the host cell some victims continued to thrive and grow. The theory of Endosymbiosis describes the origin of chloroplasts and mitochondria and their double membranes. This concept explains the idea that chloroplasts and mitochondria are the results of years of evolution started by endocytosis of bacteria and blue green algae. Based on this theory, blue green algae and bacteria are not

Endosymbiosis is the theory that eukaryotic cells were formed when a prokaryotic cell ingested some aerobic bacteria. The first step of the evolution of a eukaryotic cell is the infolding of the cellular membrane. This process takes place when the plasma membrane folds inwards and develops an envelope around a smaller prokaryotic cell. Once the smaller cell is engulfed, it becomes dependent upon its host cell. It relies on the host cell for organic molecules and inorganic compounds. However, the host cell also benefits because it has an increased output of ATP for cellular activities and becomes more productive. This ATP comes from the mitochondrion (the aerobe) that is engulfed.

Mitochondria are small organelles found in eukaryotic cells which respire aerobically. They are responsible for generating energy from food to ‘power the cell’. They contain their own DNA, reproducing by dividing in 2. As they closely resemble bacteria, it gave the idea that they were derived from bacteria (which were engulfed by ancestors of the eukaryotes we know today). This idea has since been confirmed from further investigations, and it is now widely accepted. (Alberts et al., 2010a)

7. The theory of endosymbiosis says that mitochondria and plastids used to be small prokaryotes living within larger cells. The prokaryotic ancestors of mitochondria and plastids were bacteria engulfed by a larger cell. Because they both benefited from this situation, the bacteria living inside the cell was passed down from generation to generation. The evidence is that mitochondria reproduce and move independently within the cell.

The purpose of this study is to identify four unknown organisms. The unknown organisms have been assigned randomly to six-research groups by Professor Hoffman. Each research group was provided two eukaryotes and two prokaryotes. The unknown organisms will fall into the following classifications: bacteria, algae, fungi, or protozoans. All living organisms are organized into one of three domains of life, Bacteria, Archaea, and Eukarya.

Chloroplasts are important photosynthetic organelles that present in plant cells. It is believed that chloroplasts evolve from an endosymbiotic event; engulfment of a photosynthetic cyanobacterium by a large heterotrophic host cell (1, 2). During this process proteins in the cyanobacterium has been transferred to the nucleus and also the proteins that are essential for organelle biogenesis has been transferred to the cyanobacterium making it dependent on the host. Although chloroplast proteins have estimated to consist of 3500-4000 different types of polypeptides, the protein coding capacity in chloroplast genes is approximately 200 polypeptides (3, 4). This data further suggest that most of the proteins found in chloroplast are encode by nuclear genome and transport to the chloroplast. At least, a few proteins are use secretory pathway in which first targeted to the endoplasmic reticulum and then transfer to the chloroplast through vesicles (5-7).

Primitive bacteria originated during the Precambrian time. Scientists believe that during the Precambrian time primitive bacteria was first found, and is found, in the bottom of the sea floor in hot springs about four billion years ago.(Encarta) It is believed that four billion years ago bacteria first consumed food by ingesting organ molecules or chemosynthesis which is the reaction involving chemicals. The first bacteria were one celled cyanobacteria and is trapped in the sediments of the Earth’s crust. Bacteria started from one celled organisms and lead to the creation of two-celled organisms.

The chloroplasts are organelles found in plant cells. The chloroplast is the site of photosynthesis. Since chloroplast is the site of photosynthesis it is also where sugar is produced, because glucose is a product of photosynthesis. To begin with, I made a solar power sugarcane processing plant. The reason being is that the chloroplast is where photosynthesis takes place and a product of photosynthesis is glucose (sugar), and a sugarcane processing plant produces sugar. In photosynthesis, light energy from the sun is converted into chemical energy, which is then stored and also used to make glucose. I have a light in the corner to represent the sun and solar panels on the roof, which shows energy transformation.

Photosynthetic eukaryotes use chloroplast to convert light energy from sun into chemical energy (ATP to NADPH). This is then stored in sugars (happens in dark reactions) and other fuels. This reaction underpins all life on earth. Light energy travelling from the sun has visible lights which consist of red, orange, yellow, green, blue, violet and indigo while invisible lights are ultraviolet and infrared light. In this study spinach leaves consisting living chloroplast will be isolated to investigate photosynthesis. This will be used to analyse the structure and the function of eukaryotic organelles that are crucial for the survival of all life on this planet-chloroplasts (Lilley et

Mitochondrion is considered the energy fuel of the cell. It is the primary site for the ATP production oxidative phosphorylation (OXPHOS) system. The mitochondrial OXPHOS machinery system is mainly composed of five multisubunits complexes (complexes I–V), which are produced by mitochondrial genome. Mitochondrial electron transport chain (ETC) has several essential physiological roles, in which, it is the main source of ATP production in the cell, in addition, its constituent enzyme complexes are a major source of ROS generation. Previous studies tested the effect of A on the mitochondrial bioenergetics function, and have concluded that direct exposure to A leads to significant impairment in the functionality of mitochondrial electron transport

During the experiment I noticed that in the onion cell there were no chloroplasts. There were no chloroplasts in the onion cell because in an onion the cells are used for storing energy not for photosynthesis and it grows under ground so there are no leaves on the physical body of the onion so it is unable to go through photosynthesis. The stem however of the onion has leaves above the ground but they do not serve a purpose after the onion has been picked. The cells, which contain chloroplasts that are located in the stem, are discarded therefore leaving the bulbous section of the onion that contains specialized cells that contain no chloroplasts. Also in the onion cell there were only 4 visible parts: the nucleus, the vacuole, the cell wall and the cytoplasm.

Mitochondria is considered to have developed from proteobacteria and and chloroplast from cyanobacteria. She also discovered the theory of symbiogenesis, which explores the interconnections of prokaryotic and eukaryotic cells. It also explores the concern that mitochondria and plastids have their own DNA. In contrast to Neo-Darwinism, Margulis holds the belief that life did not take over the globe by combat, but by

After the unanticipated discovery of a separate mitochondrial genome, there have been new insights into its inheritance and mutation. There is enough evidence to bolster the fact that fusion between a-proteobacteria and archaebacteria is an integral event in evolution of eukaryotic cells. However, it has also been conjectured that eukaryotic cell may have originated from prokaryotes. As a part of this evolution, many mitochondrial ancestral genes were lost. These are the genes that were no longer required in their new host cell environment. All eukaryotes contain genes of mitochondrial origin in their nuclear genome. However, this is only true for a few genes. Studies indicate that humans and mice have only 35% of mitochondrial gene products that are similar to bacteria Rickettsia. Remaining mitochondrial proteins are derived from either non-mitochondrial nuclear genes or as a result of horizontal gene transfer events. Mitochondria have developed different states during the evolution of eukaryotic cell. Aerobic mitochondria retain a small mtDNA while anaerobic mitochondria and hydrogen-producing mitochondria alter the function of respiratory chain and also maintain mtDNA.