Symbiosis And Eukaryotes

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

retains the bacteria’s characteristics and an outer layer that keep characteristics of the cell that engulfed it. Mitochondria and chloroplasts are very similar in size to prokaryotes. Mitochondria and chloroplasts have their own DNA and lack histone proteins, the DNA is circular and

Mitochondria and chloroplasts have two membranes that surround them. The inner membrane is probably from the engulfed bacterium and this is supported by that the enzymes and proteins are most like their counterparts in prokaryotes. The outer membrane is formed from the plasma membrane or endoplasmic reticulum of the host cell. The electron transport enzymes and the H+ ATPase are only found in the mitochondria and chloroplasts of the eukaryotic cell. (2)

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.

There are two main types of cells in the world. The simplest cells such as bacteria are known as Prokaryotic cells, and human cells are known as Eukaryotic cells. The main difference between each of these cells is that a eukaryotic cell has a nucleus and a membrane bound section in which the cell holds the main DNA which are building blocks of life.

“Photosynthesis is a biochemical process for building carbohydrates using energy from sunlight and carbon dioxide taken from the air”, (Morris, J. (2016) Biology How Life Works. New York, NY.). It is a system that uses plants and specific algae to synthesize molecules from both water and carbon dioxide. The oxygen we breathe and the food we eat is fueled by photosynthesis because it is an energy source. Photosynthesis occurs in eukaryotic and prokaryotic organisms and some examples are humans, trees, and plants. Biological systems use photosynthesis as an energy source. Where there is a source of sunlight, there is a chance

The cells of a eukaryote are different from any other cells because they do not have cell walls, and have organelles. An example of an organelle is the nucleus. Mitochondria are the energy providers for cells. A symbiotic relationship is when to organisms benefit from living together. When one organism lives inside the other, it is known as endosymbiosis. Chloroplasts trap sunlight and make photosynthesis possible. Once two organisms live together for a while, they loose their ability to live

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

Prokaryotes were defined in 1962 by Stanier and van Niel as “anucleate cells, without membrane enclosed organelles of respiration or photosynthesis, divided by fission not mitosis, and used peptidoglycan to strengthen their walls” (Mayr, 1998). This definition and the creation of the prokaryote/eukaryote dichotomy served to highlight the diversity and significance of the single-celled organisms previously labelled ‘Monera’ and relegated to the same kingdom status as the distinct groups of plants animals and fungi (Sapp, 2009; Woese, Kandler and

3. Mitochondria and chloroplasts are both circular or ovoid in shape, surrounded by double phosopholipid bilayers, have an intermembrane, and both are involved in ATP production by way of proton gradient. Also, both have ATP-synthases and electron transport chains appearing on the thylakoid membrane of the chloroplast and on the cristae of mitochondria.

This is an example of a rotating motor in nature. The prokaryotic flagellum does not have the same the same structure as eukaryotic flagellum. The cytoplasm contains all the enzymes needed for all metabolic reactions, since there are no organelles. Nutrients and reserves may be stored in the cytoplasm in the form of granules of glycogen, lipids, polyphosphate, or in some cases, sulphur or nitrogen. The ribosomes are for protein synthesis just like eukaryotic ribosomes but they are smaller than eukaryotic ribosomes.

The research that was conducted had the specific purpose of addressing questions on topics of individuality, reproduction, symbiotic relationships, all based around the idea of endosymbionts and the endosymbiotic theory with the eukaryotic cell. Symbiosis are the relationships between organisms that can either harm or benefit themselves. And the topic of symbiosis brings questions to the table about evolution, individuality, and cooperation between the organisms, especially when the eukaryotic cell and the evolution of it is involved; however, before we delve into these questions it is important to operationally define reproduction. In this case reproduction has evolved over time into three forms of itself: simple, collective, and scaffolded. Simple can be easily defined in the form of prokaryotes and bacteria. Collective can be described as humans, as we have reproducing parts inside of ourselves(cells). And scaffolded can be explained as reproductive objects that reproduce based entirely on surrounding resources, with the example being viruses. We will discuss how reproduction and the evolution of it applies to the eukaryotic cell as well. The conceptual framework that will be discussed in further detail later on, was made to further discuss Lewontin’s view on evolution by natural selection. He proposed three

Introduction: - The mitochondria is a double membrane organelle that is found in all eukaryotic organisms. There is some evidence that proves some eukaryotes lack mitochondria, but there is no true evidence about complete lack of mitochondria in the organisms. Mitochondria is known as a power house of the living body cell. They store energy in the cell and release it as needed. Every structure in Mitochondria have their own specific roles which helps in storing energy (See Figure 1 for details). Evidence shows that mitochondria evolved from primitive bacteria. Is it really evolved from primary bacteria or were they the new adaptation in the plant and animal body? In this paper we are going to see how Mitochondrion have been evolved in different species and what methods have been used to prove that evolution. There is still debate between scientists about whether mitochondrion really evolved from bacteria or if it was present in the cells before bacteria were present. Yung et al. [1] says that Mitochondria’s cytochromes c (which is a mitochondrial intermembrane protein that is loosely attached to the inner membrane of mitochondrial membrane) is relatively close to the bacterial medium subunit in sequence of cytochrome. However,

A single-celled eukaryote or protist can carry chlorophyll (it can be an autotrophic, photosynthetic, "alga"), it can eat other organisms (it can be an organotrophic, "protozoan" "animal"), or it may do both.