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 break down the organic substrates via biochemical reactions that convert the substrates into metabolically useful products. This removes the need for internal digestive organs in decomposers. For this reason, most decomposers are bacteria and fungi. Bacteria are widespread and can break down a myriad of organic matter. Typically 1 gram of soil contains around 40 million bacterial cells that can break down organic molecules in the soil, which in turn produce more soil.