Very small nonpolar molecules such as and go right through the cell membrane. This does not take any energy, so it is called simple .

What is the next step in muscle contraction after the actin changes shape? (apex)

The negative change found inside the plasma membrane is created by potassium ions sodium ions hydrogen ions chlorine ions

Which statement about the pancreas is not true? a. it is an endocrine organ in the abdomen. b. it release chemicals into the digestive system. c. it releases insulin to increase glucose levels. d. it release hormones into the bloodstream.