Homeostasis refers to the body’s ability to maintain a stable internal environment (regulating hormones, body temp., water balance, etc.). As the body works to maintain homeostasis, any significant deviation from the normal range will be resisted and homeostasis restored through a process called a feedback loop.

The cells that make up organisms have a big job – keeping those organisms healthy so that they can grow and reproduce. The maintenance of stable, constant, internal conditions is called homeostasis. Your cells do this by regulating their internal environments so that they are different from the external environments.

The internal life-sustaining fluid that allows sustaining exchanges and encompassing the cells, form the internal environment. The internal environment is important for normal cell function. The surrounding environment in which a living organism lives forms the external environment.

The environments in which cells grow often change rapidly. For example, cells may consume all of a particular food source and must utilize others. To survive in a changing world, cells evolved mechanisms for adjusting their biochemistry in response to signals indicating environmental change.

If the number of particles inside the cell is higher than the number of particles outside of the cell a hypotonic system has been established. Again the water molecules move more easily than the particles inside the cell. With the concentration higher inside of the cell, the water will move into the cell.

What are the four steps of signal transduction? (1) signal molecule binds to receptor that (2) activates a protein that (3) creates second messengers that (4) creates a response.