ATI TEAS VII Online Practice A – Science Questions with correct answers

Vitamin B12 is converted to methyl-cobalamin, which is consumed in a reaction where methionine synthase produces the amino acid methionine. Which of the following molecules is the catalyst in this reaction? Vitamin B12 Methyl-cobalamin Methionine synthase Methionine Correct Answer - Methionine synthase Methionine synthase has the suffix -ase, which is a standard nomenclature for enzymes. Its name further indicates that it helps to make methionine, so it is a catalyst. Which of the following classes of chemical messengers is able to easily diffuse across the cell membrane? Steroids Interleukins Catecholamines Histamines Correct Answer - Steroids Steroids are lipid-soluble. Therefore, they are able to diffuse across the hydrophobic cell membrane. A gene is being copied into a molecule that contains ribose and uracil. Which of the following cellular processes does this describe?