Search results
Results From The WOW.Com Content Network
There are two types of active transport: primary active transport that uses adenosine triphosphate (ATP), and secondary active transport that uses an electrochemical gradient. This process is in contrast to passive transport , which allows molecules or ions to move down their concentration gradient, from an area of high concentration to an area ...
Electron transport chains often produce energy in the form of a transmembrane electrochemical potential gradient. The gradient can be used to transport molecules across membranes. Its energy can be used to produce ATP or to do useful work, for instance mechanical work of a rotating bacterial flagella .
Cyclic phosphorylation is important to create ATP and maintain NADPH in the right proportion for the light-independent reactions. The net-reaction of all light-dependent reactions in oxygenic photosynthesis is: 2 H 2 O + 2 NADP + + 3ADP + 3P i → O 2 + 2 H + + 2NADPH + 3ATP. PSI and PSII are light-harvesting complexes.
Aerobic respiration requires oxygen (O 2) in order to create ATP.Although carbohydrates, fats and proteins are consumed as reactants, aerobic respiration is the preferred method of pyruvate production in glycolysis, and requires pyruvate to the mitochondria in order to be oxidized by the citric acid cycle.
Energy (in the form of ATP) would be wasted in carrying out these reactions when they have no net productivity. [citation needed] The sum of reactions in the Calvin cycle is the following: [citation needed] 3 CO 2 + 6 NADPH + 9 ATP + 5 H 2 O → glyceraldehyde-3-phosphate (G3P) + 6 NADP + + 9 ADP + 8 P i (P i = inorganic phosphate)
An important example is the formation of adenosine triphosphate (ATP) by the movement of hydrogen ions (H +) across a membrane during cellular respiration or photosynthesis. An ion gradient has potential energy and can be used to power chemical reactions when the ions pass through a channel (red).
In plants, ATP synthase is also present in chloroplasts (CF 1 F O-ATP synthase). The enzyme is integrated into thylakoid membrane; the CF 1-part sticks into stroma, where dark reactions of photosynthesis (also called the light-independent reactions or the Calvin cycle) and ATP synthesis take place. The overall structure and the catalytic ...
ATP serves as a neurotransmitter in many parts of the nervous system, modulates ciliary beating, affects vascular oxygen supply etc. ATP is either secreted directly across the cell membrane through channel proteins [37] [38] or is pumped into vesicles [39] which then fuse with the membrane.