Mitochondria
By Amy and Gabrielle

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Structure

1) largest organelles in the cytoplasm.
2) diameter between .5 and 1 micrometer.
3) tubular and shaped like a kidney.
4) found in Eukaryote cells, not in bacteria.
5) contain two membranes:
( outer membrane has a smooth exterior.
( inner membrane is folded into layers called cristae.
6) cristae divides cell into two sections.
( a matrix that lies inside the inner membrane.
( outer compartment that lies between two membranes
7) matrix contains enzymes that break down carbohydrates and in effect, carry out cellular respiration.
8) average of 3,000 to 5,000 mitochondria in the human cell.
9) contain their own DNA.
Evolution and Reproduction
1) Endosymbiosis Theory
( supports the belief that mitochondrion and chloroplasts are predecessors of Eukaryotes.
( originated from Prokaryote cells because they are the same size as bacteria and some contain cristae folds similar to those of the mitochondria.
( discovered in 1880
2)Reproduction of Eukaryote cells
( mitochondria divide into two when the Eukaryote cells split during the process of meiosis and mitosis.
( mitochondria can not be grown in a cell free culture.

Functions

1) make energy from the food we eat.
( breaks down carbohydrates and sugars into ATP
(adenosine triphosphate) in a biochemical reaction called cellular respiration.
2) cellular respiration uses oxygen and involves two main pathways.
( carbon pathway; where sugar is broken down into carbon dioxide and hydrogen.
( hydrogen pathway; where hydrogen transfers into oxygen which forms water and releases energy.
( released energy stored in molecules of ATP.
3) ATP
( stores cell's energy needed for protein manufacture, DNA replication and consumption of new organelles.
(needed for muscle contraction, pumping water through membranes, and cell movement.
4) control the concentration of water, calcium, and ions in cytoplasm. They also breakdown and recycle the energy contained in fatty and amino acids.

Mitochondrial Diseases

1) When mutations occur in the mitochondria, ATP supply decreases and therefore the energy of the cell also decreases.
( as more mutations occur throughout the body, whole systems fail and the person dies.
( the brain, heart, and skeletal muscles are the most vulnerable because they require the most energy.
( one out of 10,000 people are affected by a mitochondrial disorder.
2) symptoms:
( poor growth
( loss of motor control
( muscle weakness
( visual and/or hearing problems
( cardiac disease
( gastric-intestinal disorders
( respiratory disorders
( diabetes
( liver disease
( susceptibility to infection
( learning disabilities or retardation
( neurological problems and seizures
3) treatments:
( are not widely available
( can include vitamin and enzyme therapies and physical and occupational therapy

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Parts of The Cell