Mitochondria And Chloroplast Essay Essay Research Paper

name = Fnord Discordia

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subject= Biology

title = Mitochondria and Chloroplast Essay

papers = Biology

Mitochondria

and Chloroplast Essay

I. Introduction

Out of all the organelles there

are two that have fascinated microbiologists for the past hundred years. The

first is the mitochondria, nicknamed the “powerhouse of the cell.” The second

is the chloroplast in plant cells that have functions similar to those of the

mitochondria. What do these organelles do? What are the similarities and differences

of these organelles? This essay will help you to understand these two fascinating

organelles.

II. Mitochondria

Mitochondria are small cytoplasmic organelles.

They are five to 10 micrometers long and one to .5 micrometers wide. They main

function is to provide energy for cell activities. They house the respiratory

enzymes that convert oxygen and the products of fat, carbohydrate, and protein

metabolism into adenosine triphosphate (ATP) and guanosine triphosphate (GTP),

chemicals that have high-energy bonds. They are hollow all except for a folded

line of matter that contains the ribonucleic acid (RNA) or deoxyribonucleic

acid (DNA) of the cell.

Mitochondrion make use of a process known as oxidation

to make fat acids and pyruvate acid into (indirectly) ATP and Pi (inorganic

phosphate). The process goes as follows:

1) Oxidation of pyruvate acid

into acetyl coenzyme A.

2) Oxidation of fat acids into acetyl coenzyme A.

3) Oxidation

of acetyl coenzymes from step one and two into CO2 and NADH2.

4) Oxidation

of NADH2 by oxygen forming water.

5) Synthesis of ATP coupled to NADH2 oxidation

by process of oxidative phosphorylation.

Most of this is self explanatory

except for the last step (5). The final step contains a phrase “coupled to.”

This means that the compound (NADH2) must be present and have been oxidized

for the synthesis of ATP, similar to a catalyst’s presence of some reactions.

Although

the mitochondrion’s major purpose is to supply the cell with the much needed

ATP, it has others. Included in this list are nitrogen metabolism, porphyrin

synthesis and steroid hormone synthesis.

III. Chloroplasts

Chloroplasts

are complicated green organelles that occur within the cytoplasm of plant cells.

They are the main sites of photosynthesis. Photosynthesis is the change of

light energy, CO2 water into sugar which is used as food. They are disk shaped

organelles and are surrounded by two layers of membrane that enclose the watery

inside or stroma. Inside the stroma there are green dots called grana (grains)

that hold chlorophyll.

As with the mitochondrion the Chloroplasts use radiant

or solar energy to make a product. In this case hexose.

1) The pigment complexes

in the chloroplasts (including but not limited to chlorophyll) collect solar

energy.

2) The light energy gathered in the first step is used to run an electron

transport chain that oxidizes water into 0xygen. NADP is reduced.

3) ATP

synthesis is coupled to the electron transport train.

4) Carbon dioxide is

fixed and converted to hexose. This process requires ATP and the reduced NADP

created in step three and two respectively.

IV. Conclusion

Both the

mitochondria and the chloroplasts have complex purposes in the cell. This first

as the powerhouse that creates energy for cell activities. The second, chloroplasts

which produce food that is used to power the cell. These procedures are facinating

and more could be learned if time would allow it.

Bibliography:

Cytoplasmic

Genes and Organelles. Sager, Ruth. 1972. London.

Genetics and Biogenesis

of Chloroplasts and Mitochondria. Bucher, Th. . 1976. Amsterdan.

Mitochondria,

Chloroplasts and Bacterial Membranes. Prebble, J N. 1981. New York.

Methods

in Enzymology. Volume 207. Rudy Benardo. 1992. San Diego.