Why is a large steroid molecule able to cross the cell membrane when a smaller molecule such as adrenaline cannot?

The third stage of cellular respiration is (2 points)

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from

5. what might happen if you were to remove all light from the setup after the discs have all become buoyant? describe what you would see. explain why this would occur with relation to cellular processes like respiration. [referring to an ap biology lab in which spinach discs are placed in a sodium bicarbonate solution and exposed to light.]