Oxygen-Carrying Protein in the Blood: Hemoglobin. Hemoglobin is the protein that transports oxygen (O 2) in human blood from the lungs to the tissues of the body. Proteins are formed by the linking of amino acids into polypeptide chains.n hemoglobin, each subunit contains a heme group, which is displayed using the ball-and-stick representation in Figure 2. Each heme group contains an iron atom that is able to bind to one oxygen (O 2) molecule.
Decomposer: is an organism, usually a bacterium or fungus, that breaks down the cells of dead plants and animals into simpler substances. A fungus, such as this mushroom, is a decomposer of dead plants.
Decomposers are nature's recyclers as they break down the organic matter found in the dead bodies of plants and animals. The term 'organic matter' refers to the matter that comes from living organisms. Decomposers are chiefly the micro-organisms such as bacteria and fungi in the form or yeasts and moulds that break down bodies of dead organisms and release compounds that can be used by producers. Some of these compounds include nitrogen, phosphorus and magnesium.