Vacuoles are storage organelles that are found in both animal and plant cells. They store food or any other forms of nutrients, they also store waste products so as to protect the contamination of the cell environment. These waste products are sent out of the cell via vacuoles. In plants the vacuoles are larger than in animals. The vacuole provides plant nourishment in the scarcity of water in the external environment hence, prevents the wilting of plants.
Enzymes bind with chemical reactants called substrates. There may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. In some reactions, a single-reactant substrate is broken down into multiple products. ... The enzyme's active site binds to the substrate.
The shoreline is one of the harshest and most changeable environments for living creatures. The changing tides shift the environment dramatically within a sub-daily cycle. Here, we can consider two typical shoreline organisms, and the changing environment they must endure. Within the rocky shore environment, an octopus would be within the shallow but open sea environment during high tide, and water temperature and salinity conditions would be fairly constant. During low tide, the octopus might become trapped in a rock pool. This environment is dramatically different. The water temperature and salinity might increase drastically with exposure to solar radiation. The octopus is also more vulnerable to predation by humans and other land animals. Within the sandy shore environment, sand clams would be actively positioned at the interface of the sand and water, and will be actively filtering sea water for detritus. During low tide, the sand would be exposed to the air, and the clams would burrow down into the sand so as to avoid dessication.
