Powerhouse
- present in all portions of cytoplasm, varies between 100-1000s per cell depending on cell type
- enveloped by 2 lipid bilayers, outer/inner membrane
- inner membrane forms matrices/crests along the inside of mitochondria
- contain own dna, self-replicative
- oxidative enzymes within/on inner membrane oxidize nutrients to form co2/h2o/atp
- sources of nutrients: o2, carbohydrates (to glucose), fats (to fatty acids), proteins (to amino acids)
- atp: nitrogenous base adenine, pentose sugar ribose, 3 phosphate radicals where last 2 held by high energy phosphate bond. each bond contains about 12 kcal/mol of atp
- releasing energy: atp -> phosphate group + adp + energy
- atp uses:
- - membrane transport of substances: na/k/ca/mg/p/cl urate/hydrogen ions
- - synthesis of chemical compounds: proteins/phospholipids/cholesterol/purines/pyrimidines, up to 75% atp use
- - mechanical work: muscle fiber contraction/ciliary motion
- storing energy: opposite direction
- glycolysis: glucose enters cytoplasm + adp => pyruvic acid + atp (5% of cell energy)
- citric acid cycle: pyruvic acid => acetyl-coa in mito + hydrogen atoms, h + o + adp => atp (major atp formation)