1.3 Some proteins function as nutrient or storage proteins. For example, many of such kind exist in plant seeds, animal eggs(Ovalbumin of egg white, casein of milk). Ferritin in animal tissue function to store ion(about 4500 ions are stored in the cavity of each ferritin complex 1. 4 Some proteins are responsible for the coordinated motions(contraction, changing shape, moving about). For example, actin and myosin in muscle and nonmuscle cells. Tubulin and dynein in eukaryotic flagella and cilia1.3 Some proteins function as nutrient or storage proteins. For example, many of such kind exist in plant seeds, animal eggs (Ovalbumin of egg white, casein of milk). Ferritin in animal tissue function to store ion (about 4500 ions are stored in the cavity of each ferritin complex!). 1.4 Some proteins are responsible for the coordinated motions (contraction, changing shape, moving about). For example, actin and myosin in muscle and nonmuscle cells. Tubulin and dynein in eukaryotic flagella and cilia