Polar molecules have trouble passing through the nonpolar part of the phospholipid bilayer. Ions require ion channels and is not as easy as those that simply just diffuse through the membrane. Ion channels might require energy, too... Not glucose because those are larger molecules.
Overtime is the amount of time someone works beyond normal working hours. Normal hours may be determined in several ways: 1  by custom (what is considered healthy or reasonable by society), 2  by practices of a given trade or profession, 3  by legislation,hus, an employee might work 48 hours in one week, and 32 hours the next week (assuming over 40 hours is overtime), and be paid an extra amount equivalent to 4 hours work (8 multiplied by 0.5).
For workplace usage, see Extra time (workplace). Overtime or extra time is an additional period of play specified under the rules of a sport to bring a game to a decision and avoid declaring the match a tie or draw where the scores are the same.