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Enantiotopic groups are identical and indistinguishable except in chiral environments. For instance, the CH 2 hydrogens in ethanol (CH 3 CH 2 OH) are normally enantiotopic, but can be made different (diastereotopic) if combined with a chiral center, for instance by conversion to an ester of a chiral carboxylic acid such as lactic acid, or if coordinated to a chiral metal center, or if ...
Protons in the inter-membrane space of mitochondria first enter the ATP synthase complex through an a subunit channel. Then protons move to the c subunits. [11] The number of c subunits determines how many protons are required to make the F O turn one full revolution. For example, in humans, there are 8 c subunits, thus 8 protons are required. [12]
Symmetrical norbornanes and similarly rigid compounds (e.g. 7-oxabicyclo[2.2.1]heptane) also show complex signals for the ethylene fragments, made more complicated by additional splitting by the bridgehead protons. Reich gives several additional examples of magnetic inequivalence in acyclic and cyclic systems containing H 2 C-CH 2 fragments. [3]
An example of a proton pump that is not electrogenic, is the proton/potassium pump of the gastric mucosa which catalyzes a balanced exchange of protons and potassium ions. [citation needed] The combined transmembrane gradient of protons and charges created by proton pumps is called an electrochemical gradient.
A symporter is an integral membrane protein that is involved in the transport of two (or more) different molecules across the cell membrane in the same direction. The symporter works in the plasma membrane and molecules are transported across the cell membrane at the same time, and is, therefore, a type of cotransporter.
While there are many examples of channels within the human body, two notable ones are sodium and potassium channels. Potassium channels are typically involved in the transport of potassium ions across the cell membrane to the outside of the cell, which helps maintain the negative membrane potential of cells. As there are more potassium channels ...
The energy derived from the pumping of protons across a cell membrane is frequently used as the energy source in secondary active transport. In humans, sodium (Na + ) is a commonly cotransported ion across the plasma membrane, whose electrochemical gradient is then used to power the active transport of a second ion or molecule against its ...
Even though they share the same molar weight, glucose is more stable than galactose. This difference in stability causes galactose to be absorbed slightly faster than glucose in human body. [4] [5] Diastereoselectivity is the preference for the formation of one or more than one diastereomer over the other in an organic reaction.