In which direction does the head of the molecules of the plasma membrane face? toward the head of another molecule
toward the outside
away from water
toward the middle

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space

Which substance is a steroid? cholesterol fatty acid monosaccharide trans fat

Air can be considered a mixture. which statement does not explain why?