Metabolism - Metabolism*Apoptosis programmed cell suicide I...

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Metabolism *Apoptosis - programmed cell suicide I. Mitochondria a. has its own DNA that is independent and different from the cell’s DNA b. single stranded circular DNA -Human DNA is a double helix; bacteria have circular single stranded DNA c. Hypothesized that mitochondria were once bacteria that came into cells and forms symbiotic relationship o Symbiotic relationship also present with bacteria in intestines Bacteria feeds on fecal material and bacterial enzymes break down complex polysaccharides into more simple disaccharides and monosaccharide that our body can use for energy sources Bacteria in intestines also make main source of Vitamin K that is used in the blood clotting process Helps outcompete bad bacteria . It is hard for the bad bacteria to develop a niche because there is not enough room and their exposure to the epithelium is decreased. If this bacteria was in any other part of the body there would be an immune response against it so there is a special relationship in the intestines. Crones Disease - small intestine Ulcerative Colitis - large intestine d. Main regulator of APOPTOSIS: d.i. Once it decides it wants to cause apoptosis, it releases Cytochrome c , a protein released into the cytoplasm that interacts with other molecules, some called caspases . The caspases then break down different cellular components and start the process of apoptosis. d.ii. Occurs very frequently in cells, more in cells that are actively dividing (muscle cells ). d.iii. Ex: d.iii.1. Cancer/tumor cells –p53 inhibits cyclin dependant kinases and stops cell cycle allowing cell to repair itself. d.iii.2. Thymus T cells - all blood cells are made in bone marrow and T cells travel to thymus to mature. In the thymus there is a strict selection process where 98% of T cells get destroyed by apoptosis because they are self-reactive. d.iii.3. Embryogenesis - there are a lot of extra cells that are made and the body gets rid of the extra cells d.iii.4. Pregnancy- during lactation more mammary cells are made and then when you are done lactating apoptosis gets rid of the cells you don’t need anymore e. Don’t confuse apoptosis with NECROSIS !!! e.i. Necrosis you always have information associated with the death and apoptosis you do not have information. e.ii. With necrosis there is stuff pouring out of the cell that immune cells come and take care of but in apoptosis there are blebs that eventually disintegrate II. Apoptosis Genes Highly conserved among species: GENE GENE
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c. Elegans Humans Role Function CED-9 BCl-2 prevents oppose Bax ? Bax promotes oppose Bcl-2 ? Bcl-X long prevents oppose short ? Bcl-X short promotes oppose long CED-3 ICE promote oppose protease (digestive enzymes) CED-4 APA- promote a. These genes are highly conserved and if you flip flop them you still get apoptosis b. c. Elegans (100 cell organism) and humans function the same is proof that the process of apoptosis is conserved. ***Apoptosis is a key mechanism of aging, therefore aging is
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Metabolism - Metabolism*Apoptosis programmed cell suicide I...

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