Chapter 8

3. process of diffusion in which molecules pass across the membrane through cell membrane channels
4. the structure that contains the cell's genetic material in the form of DNA
7. captures the energy from sunlight and converts it into chemical energy
8. organelle in cells that modifies, sorts, and packages proteins and other materials for storage
10. cell organelle that stores materials such as water salts proteins and carbohydrates
11. specific protein to whose shape fits that of a specific molecular messenger
13. property of biological membranes that allows some substances to pass across it while others cannot
15. group of similar cells that perform a particular function
18. fundamental concept of biology that states that all living things are composed of cells.
19. relatively constant internal physical and chemical conditions that organisms maintain
22. fluid portion of the cell outside the nucleus
23. when comparing two solutions, the solution with the lesser concentrations of solution
24. basic unit of all forms of life
29. cell organelle that breaks down lipids carbohydrates and proteins into small molecules
30. water channel protein in a cell
31. specialized structure that performs cellular functions within a eukaryotic cell
32. converts the chemical energy stored in food into compounds that are more convenient for the cell to use

1. process by which particles tend to move from an area where they are more concentrated to an area where they are less concentrated
2. thin flexible barrier that surrounds all cells regulates what enters and leaves the cell
5. gives the cell its shape and internal organization and is involved in movement.
6. unicellular organism that lacks a nucleus
9. group of organs that work together to perform a specific function
12. group of tissues that work together to perform closely related functions
14. organism whose cells contain a nucleus
16. when the concentration of two solutions is the same
17. internal membrane system found in eukaryotic cells
20. pressure, pressure that must be applied to prevent osmotic movement across a selectively permeable membrane
21. flexible double-layered sheet that makes up the cell membrane and forms a barrier between the cell and its surroundings
25. when the comparing two solutions, the solution with the greater concentration of solution
26. strong, supporting layer around the cell membrane in some cells
27. cell organelle consisting of RNA and proteins found throughout the cytoplasm in a cell
28. diffusion of water through a selectively permeable membrane