Cells

3. hydrophobic biological molecule composed mostly of carbon and hydrogen; fats, oils, and waxes are lipids
5. an energy-requiring process by which substances move across the plasma membrane against a concentration gradient from low to high concentration
7. passive transport of ions and small molecules across the plasma membrane by transport proteins
9. diffusion of water across a selectively permeable membrane
10. the condition of continuous, random movement of particles but no overall change in concentration of materials
12. a solution with the same concentration of water and solutes as inside a cell, resulting in the cell retaining its normal shape because there is no net movement of water
16. a property of the plasma membrane that allows it to control movement of substances into or out of the cell
18. energy-requiring process by which a cell expels wastes and secretes substances at the plasma membrane
19. a protein that moves substances or wastes through the plasma membrane
20. the basic unit of structure and organization of all living organisms
21. an organic compound composed of amino acids joined by peptide bonds; a primary building block of organisms
22. plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside
23. a net movement of particles from an area of higher concentration to an area of lower concentration

1. an organic compound containing carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom
2. a solution that has a higher concentration of solute outside than inside of a cell, causing water to leave the cell by osmosis
4. a cell without a nucleus or other membrane-bound organelles
6. a plasma membrane with components constantly in motion, sliding past one another in the lipid bilayer
8. a cell with a membrane-bound nucleus and organelles; generally larger and more complex than a prokaryotic cell
11. movement of substances from a region of higher concentration to a region of lower concentration without requiring energy
13. a flexible selectively permeable boundary that helps control what enters and leaves the cell
14. A theory that states that:(1) organisms are made of one or more cells;2) cells are the basic unit of life;(3) cells come only from other cells
15. a solution that has a lower concentration of solute outside than inside the cell, causing water to flow into the cell by osmosis
17. an energy-requiring process by which large substances from outside the environment can enter a cell