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.
A counterregulatory hormone that works against the action of insulin. Most people with diabetes know that insulin is secreted by the beta cells of the pancreas. What many donât know is that other cells in the pancreas called alpha cells secrete the hormone glucagon. Glucagon is one of the counterregulatory hormones that helps the body regulate blood glucose levels. In people who donât have diabetes, when blood glucose levels fall, the beta cells secrete less insulin. In addition, the alpha cells secrete more glucagon.