7-1 Functions of Membranes. For each of the following statements, specify which one of the five general membrane functions (permeability barrier, localization of function, regulation of transport, detection of signals, or intercellular communication) the statement illustrates. (a) Intracellular organelles that are engaged in degradative chemical reactions are limited by membranes. (b) On their outer surface, cells of multicellular organisms carry specific glycoproteins that are responsible for cell-cell adhesion. (c) The interior of a membrane consists primarily of the hydrophobic portions of phospholipids and amphipathic proteins. (d) Cellular membranes have a two-layered structure with hydrophobic tails facing each other. (e) All of the acid phosphatase in a mammalian cell is found within the lysosomes. (f) The membrane of a plant root cell has an ion pump that exchanges phosphate inward for bicarbonate outward. (g) Ions and large polar molecules cannot cross the membrane without the aid of a transport protein. (h) Insulin does not enter a target cell but instead binds to a specific membrane receptor on the external surface of the membrane, thereby activating the enzyme adenylyl cyclase on the inner membrane surface.

(a) Intracellular organelles that are engaged in degradative chemical reactions are limited by membranes.-Localization of function.

(b) On their outer surface, cells of multicellular organisms carry specific glycoproteins that are responsible for cell-cell adhesion- intercellular communication.

(c) The interior of a membrane consists primarily of the hydrophobic portions of phospholipids and amphipathic proteins. -regulation of transport.

(d) Cellular membranes have a two-layered structure with hydrophobic tails facing each other.-permeability barrier

(e) All of the acid phosphatase in a mammalian cell is found within the lysosomes. -localization of function.

(f) The membrane of a plant root cell has an ion pump that exchanges phosphate inward for bicarbonate outward.-regulation of transport.

(g) Ions and large polar molecules cannot cross the membrane without the aid of a transport protein. -permeability barrier.

(h) Insulin does not enter a target cell but instead binds to a specific membrane receptor on the external surface of the membrane, thereby activating the enzyme adenyl cyclase on the inner membrane surface.-Detection of signal.

Explanation:

Biological membranes are dynamic, fluid structure that form a boundary around cell organelles and cell.They are made up of lipids and proteins. They have several functions such as restricting function, localization, communication etc,

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u