Search results
Results from the WOW.Com Content Network
The fact that a reaction is thermodynamically possible does not mean that it will actually occur. A mixture of hydrogen gas and oxygen gas does not spontaneously ignite. It is necessary either to supply an activation energy or to lower the intrinsic activation energy of the system, in order to make most biochemical reactions proceed at a useful ...
P-TEFb mediates a transition into productive elongation by phosphorylating the two negative factors and the polymerase and is regulated by association with the 7SK snRNP. The positive transcription elongation factor, P-TEFb , is a multiprotein complex that plays an essential role in the regulation of transcription by RNA polymerase II (Pol II ...
Photosynthesis and cellular respiration are distinct processes, as they take place through different sequences of chemical reactions and in different cellular compartments (cellular respiration in mitochondria). [15] [16] The general equation for photosynthesis as first proposed by Cornelis van Niel is: [17]
Calvin cycle step 1 (black circles represent carbon atoms) Calvin cycle steps 2 and 3 combined. The enzyme RuBisCO catalyses the carboxylation of ribulose-1,5-bisphosphate, RuBP, a 5-carbon compound, by carbon dioxide (a total of 6 carbons) in a two-step reaction. [6] The product of the first step is enediol-enzyme complex that can capture CO 2 ...
C 2 photosynthesis, an intermediate step between C 3 and Kranz C 4, may be preferred over C 4 for rice conversion. The simpler system is less optimized for high light and high temperature conditions than C 4, but has the advantage of requiring fewer steps of genetic engineering and performing better than C 3 under all temperatures and light ...
In oxygenic photosynthesis, the first electron donor is water, creating oxygen (O 2) as a by-product. In anoxygenic photosynthesis, various electron donors are used. Cytochrome b 6 f and ATP synthase work together to produce ATP (photophosphorylation) in two distinct ways.
Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrates, with conversion by the living organism either into simpler or more complex ...
C 2 photosynthesis (also called glycine shuttle and photorespiratory CO 2 pump) is a CCM that works by making use of – as opposed to avoiding – photorespiration. It performs carbon refixation by delaying the breakdown of photorespired glycine, so that the molecule is shuttled from the mesophyll into the bundle sheath .