The random movement of molecules across a cell membrane, from the side of the membrane where the molecules are in high concentration to the side of the membrane where the molecules are in low concentration, is called a. active transport b. The non-cellular part of a tissue, secreted by cells but not living, is called a. gastrula b. Ions are a. atoms or molecules that are equal in terms of their number of protons and neutrons. ALL of the above 71. The molecule illustrated below is a a. carbohydrate b. amino acid c. lipid d. protein e. peptide 75.
All cells arise from pre-existing cells.
The simplest of all atoms, consisting of only a single proton and a single electron is a. carbon b. Mg Gold b. Plant starch is called a. cellulose b. Peptide Bond e. junk bond 97.