Yeast do not have the malate-aspartate shuttle or the glycerol-3-p shuttle. they also do not have transporters for any convenient molecules, so they must use small, uncharged molecules to cross the membrane. however, they must regenerate cytoplasmic nadh to nad+ and move its 2e- and h+ into the matrix. yeast have acetaldehyde (structure below) and two dehydrogenase enzymes that can use acetaldehyde as a substrate: one in the mitochondria and one in the cytoplasm. based on your understanding of shuttles, suggest how the yeast shuttle may work. draw the structures of reactants and products, arrows with direction (don’t worry about reversibility) and at least 1 mitochondrial membrane. full credit requires a full cycle.

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

pv=nrt

explanation:

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.