Cellular Respiration 2 Flashcards
Cellular respiration
the process that releases energy from molecules, such as glucose, and transfers it to other molecules
carbohydrate metabolism
how many of the energy requirements of the human body are met
carbohydrate
the only food nutrient that can be used to create energy anaerobically
the preferred fuel of the body because carbohydrate requires less oxygen in order to be metabolized than fat does
Metabolic pathways
carbohydrates, proteins, and fats can all be transformed into acetylcoenzyme A, which then enters into aerobic respiration
Oxidation
the process whereby oxygen combines with another chemical, hydrogen is removed, or there is a direct loss of electrons by an atom or substance
The goal is to release hydrogen ions as much of the food’s energy is stored in the hydrogen ions
Regulatory or rate-limiting enzymes
control the rate of energy production along a metabolic pathway
pyruvic acid
when end result, the process is referred to as “aerobic glyocolysis” or “slow glycolysis”
lactic acid
when end result, the process is referred to “anaerobic glycolysis” or “fast glycolysis”
If the oxygen supply remains low
pyruvic acid is converted into lactic acid and, as it accumulates, results in muscle fatigue whereby the muscle loses its ability to contract.
pyruvic acid reacts by combining with hydrogen to produce lactic acid
remaining lactic acid produced under anaerobic conditions reconverted to pyruvic acid once it has been transported to other working muscles and heart
bridging phase
Slow glycolysis results in the breakdown of glucose to two molecules of pyruvic acid.
Pyruvic acid is then converted into acetylcoenzyme
two more hydrogen atoms are removed
acetyl coenzyme A
two molecules of pyruvic acid are converted into two molecules of acetic acid and then combined with coenzyme A
Krebs cycle
results in the removal/release of hydrogen atoms.
These hydrogen atoms are transported by coenzymes (FAD and NAD) and will eventually supply the electrons used by the electron transport system to produce ATP.
No oxygen is used directly during this stage (Krebs cycle), however, this stage requires the presence of oxygen.
electron transport system
transfer of electrons from the hydrogen atom carriers (NAD and FAD) to oxygen through a series of oxidation-reduction reactions
Oxidative phosphorlylation
the process in which NADH+H+ and FADH2 are oxidized in the electron transport system and the energy released is used to synthesize ATP from ADP and Pi.
a proton pump
Energy from NADH + H+ passes along the electron transport chain and is used to pump H+ from the matrix of the mitochondrion into the space between the inner and outer mitochondrial membranes
