Lastly, parietal cells synthesizedand secrete intrinsic factor which aids in the absorption of vitamin B12 by the ileum. Chief cells (B or arrow)are located, in cluster, at the base of the glands. They synthesize and secret hydrolytic enzymes, which areactivated at acid pH. These enzymes include gastric lipase, rennin and pepsin, which is secreted aspepsinogen and activated in the lumen. Pepsin hydrolyzes proteins. Rennin breaks down milk proteins andlipase initiates the digestion of fats.
A basis set in theoretical and computational chemistry is a set of functions (called basis functions) which are combined in linear combinations (generally as part of a quantum chemical calculation) to create molecular orbitals.
The red and blue vectors are the elements of the basis; the green vector can be given with the basis vectors. In linear algebra, a basis is a set of vectors in a given vector space with certain properties: 1  One can get any vector in the vector space by multiplying each of the basis vectors by different numbers, and then adding them up.  If any vector is removed from the basis, the property above is no longer satisfied.