1. active transport - Energy-requiring process that moves material across a cell membrane against a concentration difference.
2. cell - Collection of living matter enclosed by a barrier that separates the cell from its surroundings; basic unit of all forms of life.
3. cell membrane - Thin, flexible barrier around a cell' regulates what enters and leaves the cell.
4. cell specialization - The process in which cells develop in different ways to perform different tasks.
5. cell theory - Idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells.
6. cell wall - Strong supporting layer around the cell membrane in plants, algae, and some bacteria.
7. centriole - One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope.
8. chloroplast - Organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy.
9. chromatin - Granular material visible within the nucleus ; consists of DNA tightly coiled around proteins.
10. chromosome - Threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next.
11. concentration - The mass of solute in a given volume of solution, or mass/volume.
12. cytoplasm - Material inside the cell membrane--not including the nucleus.
13. cytoskeleton - Network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement.
14. diffusion - Process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated.
15. endocytosis - Process by which a cell takes material into the cell by in-folding of the cell membrane.
16. endoplasmic reticulum - Internal membrane system in cells in which lipid components of the membrane are assembled and some proteins are modified.
17. equilibrium - When the concentration of a solute is the same throughout a solution.
18. eukaryote - Organism whose cells contain nuclei.
19. exocytosis - Process by which a cell releases large amounts of material.
20. facilitated diffusion - Movement of specific molecules across cell membranes through protein channels.
21. Golgi apparatus - Stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum.
22. hypertonic - When comparing two solutions, the solution with the greater concentration of solutes.
23. hypotonic - When comparing two solutions, the solution with the lesser concentration of solutes.
24. isotonic - When the concentration of two solutions is the same.
25. lipid bilayer - Double-layered sheet that forms the core of nearly all cell membranes.
26. lysosome - Cell organelle filled with enzymes needed to break down certain materials in the cell.
27. mitochondrion - Cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use.
28. nuclear envelope - Layer of two membranes that surrounds the nucleus of the cell.
29. nucleolus - Small, dense region within most nuclei in which the assembly of proteins begins.
30. nucleus - The center of the atom which contains the protons, and neutrons; in cells, structure that contains the cell's genetic material (DNA) and controls the cell's activities.
31. organ system - Group of organs that work together to perform a specific function.
32. organelle - Specialized structure that performs important cellular functions within a eukaryotic cell.
33. organ - Group of tissues that work together to perform closely related functions.
34. osmosis - Diffusion of water through a selectively permeable membrane.
35. phagocytosis - Process in which extensions of cytoplasm surround and engulf large particles and take them into the cell.
36. pinocytosis - Process by which a cell takes in liquid from the surrounding environment.
37. prokaryote - Unicellular organism lacking a nucleus.
38. ribosome - Small particle in the cell on which proteins are assembled; made of rRNA and protein.
39. tissue - Group of similar cells that perform a particular function.
40. vaculoe - Cell organelle that stores materials such as water, salts, proteins, and carbohydrates.
2. cell - Collection of living matter enclosed by a barrier that separates the cell from its surroundings; basic unit of all forms of life.
3. cell membrane - Thin, flexible barrier around a cell' regulates what enters and leaves the cell.
4. cell specialization - The process in which cells develop in different ways to perform different tasks.
5. cell theory - Idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells.
6. cell wall - Strong supporting layer around the cell membrane in plants, algae, and some bacteria.
7. centriole - One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope.
8. chloroplast - Organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy.
9. chromatin - Granular material visible within the nucleus ; consists of DNA tightly coiled around proteins.
10. chromosome - Threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next.
11. concentration - The mass of solute in a given volume of solution, or mass/volume.
12. cytoplasm - Material inside the cell membrane--not including the nucleus.
13. cytoskeleton - Network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement.
14. diffusion - Process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated.
15. endocytosis - Process by which a cell takes material into the cell by in-folding of the cell membrane.
16. endoplasmic reticulum - Internal membrane system in cells in which lipid components of the membrane are assembled and some proteins are modified.
17. equilibrium - When the concentration of a solute is the same throughout a solution.
18. eukaryote - Organism whose cells contain nuclei.
19. exocytosis - Process by which a cell releases large amounts of material.
20. facilitated diffusion - Movement of specific molecules across cell membranes through protein channels.
21. Golgi apparatus - Stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum.
22. hypertonic - When comparing two solutions, the solution with the greater concentration of solutes.
23. hypotonic - When comparing two solutions, the solution with the lesser concentration of solutes.
24. isotonic - When the concentration of two solutions is the same.
25. lipid bilayer - Double-layered sheet that forms the core of nearly all cell membranes.
26. lysosome - Cell organelle filled with enzymes needed to break down certain materials in the cell.
27. mitochondrion - Cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use.
28. nuclear envelope - Layer of two membranes that surrounds the nucleus of the cell.
29. nucleolus - Small, dense region within most nuclei in which the assembly of proteins begins.
30. nucleus - The center of the atom which contains the protons, and neutrons; in cells, structure that contains the cell's genetic material (DNA) and controls the cell's activities.
31. organ system - Group of organs that work together to perform a specific function.
32. organelle - Specialized structure that performs important cellular functions within a eukaryotic cell.
33. organ - Group of tissues that work together to perform closely related functions.
34. osmosis - Diffusion of water through a selectively permeable membrane.
35. phagocytosis - Process in which extensions of cytoplasm surround and engulf large particles and take them into the cell.
36. pinocytosis - Process by which a cell takes in liquid from the surrounding environment.
37. prokaryote - Unicellular organism lacking a nucleus.
38. ribosome - Small particle in the cell on which proteins are assembled; made of rRNA and protein.
39. tissue - Group of similar cells that perform a particular function.
40. vaculoe - Cell organelle that stores materials such as water, salts, proteins, and carbohydrates.