Yeast is a fungus and needs a supply of energy for its living and growth. Sugar supplies this energy. (Your body also gets much of its energy from sugar and other carbohydrates.). Yeast can use oxygen to release the energy from sugar (like you can) in the process called respiration. So, the more sugar there is, the more active the yeast will be and the faster its growth (up to a certain point-even yeast cannot grow in very strong sugar-such as honey).
Molecules are held together by either covalent bonding or ionic bonding. Several types of non-metal elements exist only as molecules in the environment. For example, hydrogen only exists as hydrogen molecule. A molecule of a compound is made out of two or more elements.
Certain parts of a molecule will. be attracted to other parts of different molecules and will cause them to stick together. Since all. of the molecules are the same, this attraction will be very strong. A water droplet on a desk, for. example, is made of many tiny water molecules that are attracted to each other.