Lab 5
-
Upload
khder-hussein -
Category
Documents
-
view
28 -
download
1
Transcript of Lab 5
November 23, 2014
practical Cell biology Lab 5
MitochondriaThe energy required to power living cells comes from the sun. Plants capture
this energy and convert it to organic molecules. Animals can gain this energy by
eating plants or other animals. The most efficient way for cells to harvest energy
stored in food is through cellular respiration, a catabolic pathway for the
production of adenosine triphosphate (ATP).Glucose, derived from food, is broken
down during cellular respiration to provide energy in the form of ATP and heat.
Cellular respiration has three main stages: glycolysis, the citric acid cycle and
electron transport. The Krebs cycle and electron transport occur within
mitochondria, Mitochondria are known as the powerhouses of the cell.
Mitochondria are bounded by a double membrane.Each of these membranes
is a phospholipid bilayer with embedded proteins. The outermost membrane is
smooth while the inner membrane has many folds. That folding increases the
surface area inside the organelle. Many of the chemical reactions happen on the
inner membrane of the mitochondria.
The double membranes divide the mitochondrion into two distinct parts: the
intermembrane space and the mitochondrial matrix. The intermembrane space is
the narrow liquid part between the two membranes while the mitochondrial matrix
is the part enclosed by the innermost membrane. Several of the steps in cellular
respiration occur in the matrix due to its high concentration of enzymes also matrix
contains mitochondrial deoxyribonucleic acid (mtDNA) and mitochondria
reproduce independently of the cell by fission.
A
B
November 23, 2014
practical Cell biology Lab 5
In general, the number of mitochondria per cell and the number of
cristae per mitochondrion are related to the energy requirement for the function
carried out by that cell type. So the number of mitochondria in a cell depends on
the cell's function. Cells with particularly heavy energy demands, such as muscle
cells, have more mitochondria than other cells
The mitochondrion in figure A has small number of cristae. In the figure B, the mitochondrion contains many long and closely packed cristae.