Some microorganisms such as yeast produce energy in oxygen-free environments through anaerobic cellular respiration. Anaerobic cellular respiration is where oxygen is not used. Yeast produces energy by converting sugars into alcohol, gas or acetic acid. <span>This process is called fermentation. </span>Ethanol is a by-product of fermentation. Humans have used fermentation to produce food and drink since the Neolithic Age. Fermentation makes yoghurt from milk by producing lactic acid. It also produces alcoholic beverages such as wine from grapes.
Carbon dioxide, hydrogen, and water
Monosaccharides contain a single unit; disaccharides<span> contain two sugar units; and polysaccharides contain many sugar units as in polymers - most contain glucose as the monosaccharide unit. Number of Carbons: Monosaccharides can be further classified by the number of carbons present.</span>
Antigens: Antigens are substances that cause an immune response in the body by identifying substances in or markers on cells. Your body produces antibodies to fight antigens, or harmful substances, and tries to eliminate them.
Antibodies: Antibodies are proteins which belong to a class known as immunoglobulins. They are made up of chains of amino acids joined by peptide bonds.
Cellular immunity: Lymphocytes act against target cell,Acts directly by killing infected cells,Acts indirectly by releasing chemicals that enhance inflammatory response; or activating other lymphocytes or macrophages.
Hope this help!!