During cellular respiration, every living thing in this food web uses gas and releases back into the environment.
a. carbon dioxide: oxygen
b. oxygen: carbon dioxide
c. carbon dioxide: hydrogen
d. carbon dioxide: water vapor

You have a solution that contains phospholipid vesicles in a test tube. these vesicles have phospholipid bilayers, but do not contain any membrane transporters. you add a number of different molecules to the solution, and wait a period of time for them to equilibrate. if you could measure the concentration of each molecule, for which of the following would you expect to measure equal concentrations inside and outside of the vesicles? assume for this question that the overall osmolarity inside and outside the vesicles is the same (that is, there is no appreciable diffusion of water across the membrane). (select two answers) an amino acid with a hydrophobic side-chain a small non-polar molecule a negatively charged ion a small polar molecule a small lipid hormone

The earth's oceans are made up of chlorine, and trace elements. a) carbon, oxygen b) oxygen, silicon c) hydrogen, oxygen d) nitrogen, oxygen

Describe the relationship between isotonic solutions, equilibrium, and water movement into and out of a cell.