The Evolution Of Eukaryotic Cells

Essentially, the end goal of the experiment was to analyze our mitochondrial DNA at the D loop locus to compare to locus sequences around the world to find others that may share a common ancestor in our maternal lines. Methods: We continued the experiment using the same DNA we extracted from the beginning of the lab, except this time looking at the D Loop from mitochondrial DNA. PCR reactions were set up using the reagents: Buffer, MGCl2, dNTPs, Forward Primer, Reverse Primer, taq enzyme, and water. A positive control was made with the Master Mix and

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)

Mitochondria, dubbed the ‘powerhouse of the cell’, are a type of organelle present in most human cells. Their primary function is to generate Adenosine Triphosphate (ATP), the cell’s principal source of chemical energy. Unlike most other organelles, mitochondria store their own set of genetic material, distinct from the DNA situated in a cell’s nucleus. Although this ‘mitochondrial genome’ represents only 0.1% of a cell’s genetic information, it often plays a significant role in development.

The article Replacing the cell’s power plants by Eric A. Shoubridge discusses the DNA found within mitochondria. Mitochondrial DNA (mtDNA) differs from nuclear DNA as it is inherited from only the mother. However, the mtDNA can also contain mutations which, similar to the nuclear DNA, have the potential to cause severe complications. Due to the mtDNA being restricted to the mitochondria multiple approaches have been developed in effort to reduce or prevent the amount and effect of mtDNA mutations.

Mitochondrial cytopathy is a genetic heritable disorder [5]. It occurs as a result of DNA mutation in the gem-line cells that can be transmitted to the second generation. This type of genetic disorder is often caused by mutations in the mitochondrial DMA versus the nucleic DNA. The mitochondria DNA is 20-30 times more susceptible to acquire mutations secondary to absence of DNA repair mechanisms in the mitochondria, giving rise to frequent point mutations or deletions in the mtDNA during cell division[1]. Such mutations are inherited exclusively from the maternal mitochondria. The paternal mitochondria do not contribute to the fetal mitochondria [6]. When some of the mitochondria in the ovum have mutations in their DNA, some of those defected mitochondria will go to daughter cells upon division. If the cells receiving the defected mtDNA contribute to forming tissues that are actively dividing after birth, they will be eliminated by the natural selection process after successive cell divisions. In contrast, if the cells inheriting the defected mitochondria developed into organs or tissues of limited dividing ability, this will result in problems related to energy metabolism in that organ [6]. Due to the random nature of the process, defected mitochondria may end up randomly in different types of tissue and at different concentration. This explains the variations in the manifestation, progression, prognosis and severity of the disorder.

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.


Bloom's Level: 1. Remember
Learning Outcome: 06.02.01 Describe the general features of mitochondrial genomes.
Section: 06.02
Topic: Extranuclear Inheritance: Mitochondria

“Eukaryotic cells are complex and include all animal and plant cells. Prokaryotic cells are smaller and simpler, e.g. Bacteria” - (AQA 2008)

Many physiological processes in the cells require the participation of both intra- and extra-mitochondrial enzyme reactions. A link between mitochondria and cytosol is provided by a group of proteins known as the mitochondrial carriers (MCs) family (Arco & Satrustegui, 2005; F. Palmieri, 2004). MCs comprise a family of about 40-50 proteins, depending on the organism, and provide the main communication between mitochondrial matrix and extra-mitochondrial spaces by transporting a wide range of metabolites, nucleotides and cofactors.

The hypothesis for eukaryote origin states that a large, anaerobic prokaryote engulfed an aerobic bacterium, which hasn’t been digested but stabilized as an endosymbiont instead, became integrated into host cells as mitochondria (Yamaguchi et al, 2012). Up until now there has not been many organisms that show features of a transition

Eukaryotic cells are unique because they have unique organelles. These organelles are membrane bound. These organelles have an additional transportation system. The membranous organelles are enclosed by the same type of material as the plasma. Therefore the can move through the cell easier. I thought this was really interesting because it like the organelles have like a car to use for transportation. The eukaryotic animal cells have many parts. As we go deeper will explain their importance.

Mitochondria are important intracellular organelles responsible for life & death. The mitochondrial matrix has multiple copies of mitochondrial DNA whose replication are not related to the cell cycle. Thus replication of mitochondrial DNA occurs several times and leads to mutations due to error in replication. This leads to mitochondrial dysfunctions which subsequently leads to oxidative stress and an increase in ROS . The main function of mitochondria is to produce ATP by oxidative phosphorylation. It regulates a variety of metabolic and signaling pathways and also plays an important role in programmed cell death. Recent studies using animal models have shown the decline in mitochondrial function with age thus bringing out a relationship between mitochondrial dysfunction and

The second important endosymbiotic event occurred as a result, in the acquisition of mitochondria by the earliest eukaryotes (Avissar et al., 2016). Mitochondria are responsible for aerobic cellular respiration in eukaryotic cells, and for a long time it was believed that they were simply organelles. But much like plastids in photoreactive eukaryotes, the evidence points to mitochondria having been absorbed by early eukaryotes, forming a symbiotic relationship in which the larger cell protected the smaller and provided a ready source of nutrients, and in turn the mitochondria allowed the larger cells to process all of the new molecular oxygen as an energy source to promote glycolysis (Cooper, 2000).

Mitochondrial disease is the malfunctioning of the mitochondria organelle located in every cell of the human body except the red blood cells. These organelles are responsible for the synthesis of 90% of the ATP energy required for a normal bodily function. Consequently if a patient is diagnosed with mtDNA disease, their individual cells will generate less energy than required resulting

Biologists use the ideas of cell theory, hereditary and genetics, and evolution through natural selection in many different ways. While being very different areas of study, they all share a core idea. This idea is that cells duplicate, and sometimes experience random mutations. From this very basic idea, scientists can theorize that all life on earth came from one or a few very simple cells, and are related through this. But the diversity of life today also shows how these related cell groups evolved and changed.