2.8 Cell Respiration Flashcards
Slow oxidation
A process through which cells break down their organic nutrients with the help of enzymes. These enzymes catalyse a series of reactions where covalent bonds are broken (oxidized?)one at a time and everytime energy is released. Ex: glucose
Rapid oxidation
Stored Chemical energy released when we burn something in the form of light and heat. Its found in covalent bonds of fatty acids, amino acids, a glucose
Goal of releasing energy
To trap the released energy in the form of ATP, usually glucose otherwise other molecules like fatty acids or amino acods are used
Glycolysis (1st strp of cell resporation)
Glucose enters cell through plasma membrane into cytoplasm. Enzyme modifies it, 2nd enzyme modifies it more. Series of reactions that turns 6 carbon glucose into 3 carbon. Most covalent bonds broken, som energy used for ATP.
Pyruvate
Name given to nutrient once it has gone through reactions and is a 3 carbon molecule
ATP in glycolysis
2 ATP needed to start glycolysis, 4 produced by the end of it.
Glycolysis (def)
The metabolic pathway that is common to all organisms on earth
Anaerobic
Organisms that derive their ATP completely without the use of oxygen.
2 pathways: alcoholic fermentation and lactic acid fermentation
Alcoholic fermentation
Yeast a single celled organism uses it for ATP when oxygen not present. After glycolysis, 2atp gained and 2 pyruvat, yeast converts pyruvat into ethanol, 2carbon, 1 is lost given in CO2. Both are waste products released in the environment. (Co2 helps bread to rise)
Lactic acid fermentation
When organisms cant supply enough oxygen ex: when exercise above capacity. Excess pyruvat molecules converted into lactic acid molecules, 3C therefore no CO2 . This type of fermentation allows glucolysis to continue with a small gain of ATP in addition to atp from aerobic pathways
Aerobic pathway (the process)
2 pyruvat molecules enter mithocondrion and are metabolized more. First loses a co2 molecule becomes acetyl-CoA, enters a krebs cycle. Some atp generated during this cycle, more after during reactions with oxygen
The krebs cycle
A series of reactions that start and end with the same molecule. During aerobic cell respiration where 2co2 are produced from each pyruvat. Regain of the 1st molecule allows it to be repeated
Aerobic respiration (def)
Breaks down (oxidises) a glucose molecule and the end-products are co2 and water plus a much higher number of ATP molecules than anaerobic respiration
Cellular respiration
The process by which cells break down glucose with enzymes to release energy in the form of atp
Glycolysis in aerobic vs anaerobic respiration
In aerobic: mithocondrion
In anaerobic: cytoplasm
