Mitochondria Essay, Research Paper
Mitochondria
Mitochondria are responsible for energy production. They are also the
responsible location for which respiration takes place. Mitochondria contain
enzymes that help convert food material into adenosine triphosphate (ATP), which
can be used directly by the cell as an energy source. Mitochondria tend to be
concentrated near cellular structures that require large inputs of energy, such
as the flagellum. The role of the mitochondria is very important in respiration.
In the presence of oxygen, pyruvate or fatty acids, can be further
oxidized in the mitochondria. Each mitochondrion is enclosed by two membranes
separated by an intermembrane space. The intermembrane space extends into the
folds of the inner membrane called cristae which dramatically increase the
surface area of the inner membrane. Cristae extend into a dense material called
the matrix, an area which contains RNA, DNA, proteins, ribosomes and range of
solutes. This is similar to the contents of the chloroplast stroma and like the
chloroplast, the mitochondrion is a semi-autonomous organelles containing the
machinery for the production of some of its own proteins. The main function of
the mitochondrion is the oxidation of the pyruvate derived from glycolysis and
related processes to produce the ATP required to perform cellular work.(Campbell
182-9)
Pyruvate, or fatty acids from the breakdown of triglycerides or
phospholipids, pass easily through pores in the outer mitochondrial membrane
made up of a channel protein called porin. The inner membrane is a more
significant barrier and specific transport proteins exist to carry pyruvate and
fatty acids into the matrix. Once inside the matrix, pyruvate and fatty acids
are converted to the two carbon compound acetyl coenzyme A (acetyl CoA). For
pyruvate this involves a decarboxylation step which removes one of the three
carbons of pyruvate as carbon dioxide. The energy released by the oxidation of
pyruvate at this stage is used to reduce NAD to NADH. (185)
The C2 acetyl CoA is then taken into a sequence of reactions known as
Krebs cycle which completes the oxidation of carbon and regenerates an acceptor
to keep the cycle going. The oxidation of the carbon is accompanied by the
reduction of electron acceptors and the production of some ATP by substrate
phosphorylation. The C2 acetyl CoA is coupled to oxaloacetate, a C4 acceptor in
the cycle. The product is citrate a C6 compound. This first product, citrate,
is the reason the cycle is sometimes called the citric acid or ticarboxylic acid
cycle, referring it after the scientist whose lab most advanced our
understanding of it, Sir Hans Krebs. (Comptons 160)
Two of the early reactions of the cycle are decarboxylations which
shorten citrate to succinate a C4 compound. The CO2 lost does not actually
derive from acetyl CoA, during that cycle, but two carbons are lost which are
the equivalent of the two introduced by acetyl CoA. The decarboxylation steps
are again accompanied by the reduction of NAD to NADH. The formation of
succinate also sees the formation of an ATP molecule by substrate
phosphorylation. (Brit 1041)
The last part of the cycle converts C4 succinate back to C4 oxaloacetate.
In the process another reaction generates NADH while another reduces the
electron acceptor FAD (Flavin Adenine Dinucleotide) to FADH.
The final stage of respiration in the mitochondria involves the transfer
of energy from the reduced compounds NADH and FADH to the potential energy store
represented by ATP. The process is oxidative phosphorylation and it is driven
by a chemiosmotic system analogous to that seen in chloroplasts. (Moore 88-9)
The inner membrane contains an electron transport chain that can receive
electrons from reduced electron carriers. The energy lost as electrons flow
between the components of the electron transport chain is coupled to the pumping
of protons from the matrix to the intermembrane space. The matrix is
alkalinized while the intermembrane space is acidified. The electrons are
ultimately combined with molecular oxygen and protons to produce water.
Respiration is aerobic when oxygen is the terminal electron acceptor. (Brit
1042)
The energy that was contained in the pyruvate molecule has at this point
been converted to ATP by substrate phosphorylation in glycolysis and Krebs cycle
and to a free energy gradient of protons across the inner membrane known as the
proton motive force (PMF). The gradient of protons will tend to diffuse to
equilibrium but charged substances like protons do not easily cross membranes.
Proton complexes in the inner membrane provide a channel for the protons to
return to the matrix. Those protein complexes function as an ATPase, an enzyme
that synthesizes ATP, because the energy liberated as the protons work to
diffuse back to the matrix is used to push the equilibrium between ADP+Pi and
ATP strongly toward ATP. (Campbell 182)
The electron transport chain has three sites along it that pump protons
from the matrix. NADH donates its electrons to the chain at a point where the
energy input is sufficient to drive all three proton pumping sites. FADH is less
energetic than NADH and its electrons are donated at a point that drives two
proton pumping sites. It is also possible for the NADH produced in glycolysis to
enter the mitochondrial matrix and donate electrons to the electron transport
chain. Depending on the system, NADH from glycolysis may be able to drive two or
three proton pumping sites. For eukaryotes, only two pumping sites are driven;
for prokaryotes, three. (184-5)
The importance of mitochondria is unremarkably, a key element in the
process of respiration. Between the three distinct sections of respiration,
glycolysis, Krebs Cycle, and Electron Transport, the mitochondrion is the site
of which most of it takes place, either inside of the mitochondrion or outside
it.
Другие работы по теме:
Biology Test Cells Essay Research Paper My
Biology Test: Cells Essay, Research Paper My brother was studying for his biology test. The next morning he was telling me about the dream he had. He said he traveled through a cell. I started to call him insane. My brother have an educational dream? I thought to myself, impossible.
Melatonin And The Pineal Gland Essay Research
Paper Set deep in our brains is a tiny gland called the pineal gland. This tiny gland is in charge of the endocrine system, the glandular system that controls most of our bodily functions. The pineal runs our body clocks+, and it produces melatonin; the hormone that may prove to be the biggest medical discovery since penicilin, and the key to controlling the aging process.
The Five Kingdoms Essay Research Paper The
The Five Kingdoms Essay, Research Paper The Five Kingdoms Monera This biological kingdom is composed of bacteria and cyanobacteria, one-celled (sometimes colonial) organisms whose cells lack a nuclear envelope, mitochondria, or plastids. They reproduce asexually through fission (splitting in two) and mainly gain their nutrition by absorbing it from their environment (though some species are chemoautotrophs or photosynthetic).
Origins Of Mitochondria And Chloroplast Essay Research
Paper Origins of mitochondria and chloroplast Both mitochondria and chloroplast have an inner and outer membrane, each a phospholipid bilayer with a unique collection of embedded proteins. The inner membrane of the mitochondria is convoluted, with infoldings called cristae which gives it a greater surface are to enhance productivity of cellular respiration, it also encloses the mitochondrial matrix, and contains built in enzymes that make ATP.
Mitochondria Essay Research Paper Mitochondria are the
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.
Mitochondria 2 Essay Research Paper MitochondriaMitochondria are
Mitochondria 2 Essay, Research Paper Mitochondria Mitochondria are tiny organelles found in nearly all eukaryotic cells. They are rather large organelles ranging from 0.5+m to 10+m in length and 1+m in diameter. The mitochondria are the energy factories of the cell and are located in the cytoplasm. They are the sites of cellular respiration.
The Month In A Life Of A
Gamete (sperm) Essay, Research Paper A Month in The Life of A Gamete My name is RAMBO. I and my millions of brothers and sister gametes have been confined in our prison like holding cells called testes. Each day many more gametes are produced and held captive inside the testes which hang in a storage sac called the scrotum.
Cloning Essay Research Paper Cloning What is
Cloning Essay, Research Paper Cloning What is a Clone? A clone is a group of genetically identical cells. For example, tumors are clones of cells inside an organism because they consist of many replicas of one mutated cell. Another type of clone occurs inside a cell. Such a clone is made up of groups of identical structures that contain genetic material, such as mitochondria and chloroplasts.
Glucose Essay Research Paper Extracting energy from
Glucose Essay, Research Paper Extracting energy from glucose Two different pathways are involved in the metabolism of glucose: one anaerobic and one aerobic. The anaerobic process occurs in the cytoplasm and is only
Explain With Aid Of A Diagram The
Working Of The Electron Microscope Essay, Research Paper The diagram below shows a picture of an electron microscope. This is a type of microscope that makes use of a
What Is A Cell Essay Research Paper
What is a Cell? The English scientist Robert Hooke who used a makeshift microscope of his own invention to examine a variety of objects, including a thin piece of cork, made the first observations of cells in 1665. Noticing the rows of little boxes that made up the dead wood’s tissue, Hooke created the term “cell” because the boxes reminded him of the small cells the monks in the monastery lived in.
Endosymbiosis Essay Research Paper Scientists have formulated
Endosymbiosis Essay, Research Paper Scientists have formulated many theories about the origin of life and how it evolved into the various forms known today. These ideas come from the evidence of the fossil record, from laboratory simulations of conditions on the earth, and from consideration of the structure and function of cells.
Mitochondria S Effect On Aging And Disease
Essay, Research Paper Mitochondria are the powerhouse of the cell. Their sole responsibility is to provide energy for the cell. They do this by synthesizing a molecule known as ATP, which the cell uses as energy. Mitochondria are different from the rest of the cell organelles because they contain their own DNA outside the nucleus.
Sheep Cloning Essay Research Paper Cloning is
Sheep Cloning Essay, Research Paper Cloning is one area of genetics that is advancing very rapidly, and it is therefore very controversial. A clone is a group of genetically identical cells descended from a single ancestor. A clone is made up of plasmids, groups of identical structures, that contain genetic material such as mitochondria and chloroplasts.
Cells Essay Research Paper Essay of Eukaryotic
Cells Essay, Research Paper Essay of Eukaryotic Organelles The mitochondria has an egg shape structure. The mitochondria consists of an inner and outer membrane. The outer membrane is what shapes the organelle to its egg like shape. The inner membrane which folds inward makes a set of “shelves” or cristae that allow the reactions of the mitochondria to take place.
Cell Mitosis Essay Research Paper The life
Cell Mitosis Essay, Research Paper The life Process of a cell In my report you will learn about the life process of a cell based on the two main functions, metabolism and mitosis. You will learn about the four stages of metabolism: ingestion, digestion, respiration, and excretion, and how the cell completes them.
How Changes In The Atmosphere Eukarotes And
Multicellularity Have Occured And Influenced Life On Earth Essay, Research Paper About 2.5 billion years ago, oxygen began slowly to accumulate in the atmosphere, as a result of the photosynthetic activity of the cyanobacteria. Those prokaryotes that were able to use oxygen in ATP production gained a strong advantage, and so they began to prosper and increase.
Cells Essay Research Paper CellsCells are the
Cells Essay, Research Paper Cells Cells are the basic unit of all life. Even though they are the smallest unit of life they are highly complex. Each cell has enough parts to it to
Atp Production Essay Research Paper ATP ProductionMetabolism
Atp Production Essay, Research Paper ATP Production Metabolism, which encompasses glycolysis, the Kreb s cycle, and the electron transport system, occurs in the mitochondria of cells. The mitochondria consist of a double membrane and an inner compartmentalization called the matrix. Each of the processes of metabolism occurs in specific locations in and around the mitochondria.
Dollys Mixture Essay Research Paper CLONING SPECIAL
Dollys Mixture Essay, Research Paper CLONING SPECIAL REPORT + + + + + + + + + + + + + + + + + + + + + + + + Dolly’s mixture Clones are not the perfect replicas we thought.By Philip Cohen Dolly the sheep does not have precisely the same genetic make-up as the adult sheep from which she was cloned. A study shows that the genes in her mitochondria–the powerhouses of cells–came from another sheep involved in the experiment.
Cells Essay Research Paper NucleusCell WallCell Membrane
Cells Essay, Research Paper Nucleus Cell Wall Cell Membrane Ribosome Mitochondria Vacuoles Nucleolus Endoplasmic Reticulm Lysosomes 5. Have the “cell membrane people” cut the large piece of plastic wrap in half and place each
The Origin Of Eukaryotic Cells Essay Research
Paper The origin of Eukaryotic cells In the beginning of the creation of Earth volcanoes erupted all over the planet. During this period there was a time where a brief cooling period was allowed to take place. When this period took place evaporation caused a downpour of rain which flooded the ocean creating the ocean.
Cellular Respiration Essay Research Paper Cellular respiration
Cellular Respiration Essay, Research Paper Cellular respiration begins with glucose. Glucose is the primary fuel used in glycolysis, the first stage of cellular respiration. This molecule is found in the gel-like substance called cytoplasm that fills the cell. In glycolysis, glucose undergoes phosphorylation by ATP.
Transgenic Technology Cloning Technique Essay Research Paper
Transgenic Technology: “Cloning” Techniques Amanda Kruvand Transgenic Technology Transgenic technology can introduce a gene or genes from one individual’s DNA into the DNA of another individual- even when the genes come from different species. The gene or genes are inserted in to a fertilized egg and become integrated in to the DNA of that zygote.
Cell Membrane Electron Transport Chain Biochemical
Pathway Essay, Research Paper 1. The cell membrane structure is vital to the life of the cell. The cell membrane is shaped as having a phosphate head at the very outer surface, and two fatty acid tails hanging from it. The membrane is double, so at the tip of the fatty acid tails, there are two more fatty acid tails attached to another phosphate head.
Endurance Essay Research Paper Endurance plays a
Endurance Essay, Research Paper Endurance plays a major role in many athletic activities. Without endurance training, many athletes would not be able to compete in their respective sports. Endurance training involves low resistance and high repetitions, but what exactly does this do to your body and how does it do it?
Cell Structure Definitions Essay Research Paper DefinitionsCell
Cell Structure Definitions Essay, Research Paper Definitions: Cell Wall A structure made of cellulose that is, in the plant, responsible for many tasks. Firstly, it maintains the shape of the cell, and secondly it protects the cell from external forces. It also serves as a connector between the cell in question and its neighboring cells.
Plant Cell Essay Research Paper I am
Plant Cell Essay, Research Paper I am your usual plant cell. There are trillions of my kind on all plants, grass, and trees. My breed ranges from ten to a hundred micrometers. I am approximately twenty micrometers since I dwell in grass. My organelles stretch out to one to ten micrometers. If you are asking what I really do and how I live, I am going to answer them in this paper.
Biology 2 Essay Research Paper BIOLOGY 2
Biology 2 Essay, Research Paper BIOLOGY 2 1. ORAGANELLES2. TYPES OF CELLS3. OSMOSIS/ DIFFUSION4. CELL THEORY 1. ORGANELLES small structures embedded in the cytoplasm e.g. plastids, vacuoles, mitochondria, lysosomes, centrosomes, endoplasmic reticulum (e.r.) 2. TYPES OF CELLS A.
Electron Transport Essay Research Paper Electron Transport
Electron Transport Essay, Research Paper Electron Transport Essay Electron transport is the last phase and most important phase of cell respiration. It accounts for most of the ATP made in cell respiration. Cell respiration makes a total of thirty eight ATP?s, two from Glycolysis, two from the Krebs cycle and thirty four from electron transports.
The Plant Cell Essay Research Paper Cell
The Plant Cell Essay, Research Paper Cell Wall Size: Around 1? Basic Function: * Hold the shape of the cell. * Strengthen the cell. Covering the cell membrane of the plant cell, there is the cell wall. The cell wall is composed of two