The human digestion starts in the small intestine gets the
most of the nutrients in your food, and your circulatory system passes them on
to other parts of your body to store or use.
When food enters the small intestine, villi along the intestine wall
along with enzymes help break down the food, and takes a long journey. The
stomach is right above the small intestine, and the small intestine is all
wrapped around, and isn't that thick. Nutrients from the food are released to
the whole body as energy. The small intestine brings the food to the large
intestine, which is five feet long and is near your pelvis, or hips. The large
intestine connects to the rectum, and then to the anus. In the large intestine,
all the water is absorbed as well as salt.
Receptors detect changes in the environment. For a stimulus to elicit a response, certain cells must have an appropriate receptor. Stimulation of the receptor initiates a specific signal pathway.
The plasma membrane or the cell
membrane is the one that protects the cytoplasm of a cell. It is mostly
composed of lipids and proteins. It has a phospholipid bilayer that controls
the entering and exiting of molecules in the cell and at the same time,
provides protection for the cell or plasma membrane. It has polar head and a
nonpolar tail. Proteins embedded within the phospholipid bilayer have the same
function of the plasma membrane that includes selective transport. The
phospholipid bilayer consists mainly of the lipid molecules.
a basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.
The light independent reactions of photosynthesis are dependent on temperature. They are reactions catalysed by enzymes. As the enzymes approach their optimum temperatures the overall rate increases.
