Delete Content. A plasma membrane is permeable to specific molecules that a cell needs. Transport proteins in the cell membrane allow for selective passage of specific molecules from the external environment. Each transport protein is specific to a certian molecule (indicated by matching colors).
The pancreas contains cells which release both insulin and glucagon. The endocrine system consists of a number of different glands which secrete hormones that dictate how cells and organs behave.
Back to basics. Insulin is a hormone secreted by the pancreas that helps regulate the way the body uses glucose. Its main job is to allow glucose in the blood to enter cells of the body where it can be used for energy. In people who donât have diabetes, the pancreas changes how much insulin it releases depending on blood glucose levels. Eating a chocolate bar? The pancreas releases more insulin. Sleeping? The pancreas releases less insulin until the wee hours of the morning when the hormones secreted in the early morning naturally increase insulin resistance, so the pancreas needs to release a little more. Insulin also controls how much glucose is produced and released from the liver.