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-Bacteria Engines of Earth's Nutrient Cycles. Decomposers are the organisms that eat, digest and break down once living things which have died. They are absolutely essential in the nutrient cycles. In essence, all living things, including humans, are borrowing the elements that make up their bodies. On death we need to recycle them back so other plants and animals can use them. Recycling the elements is essential.