8.1-2 Biology

1. some substances can pass across them while others cannot
4. small organelles filled with enzymes
8. a thin flexible barrier that surrounds a cell
9. small particles of RNA and protein found throughout the cytoplasm
10. the basic units of all living things
12. a strong supporting layer around the membrane
14. the power plant of the cell
16. a network of protein filaments that gives eukaryotic cells their shape
18. large saclike, membrane enclosed structures that store water, salts, proteins, and carbohydrates
19. cells that do not enclose their DNA in nuclei

2. an internal membrane system contained in eukaryotic cells
3. a stack of flattened membranes that proteins are moved into
5. the biological equivalent of a power plant, in a plant
6. gives cell membranes a flexible structure that forms a strong barrier between the cell and its surroundings
7. a fundamental concept of biology
11. the portion of the cell outside the nucleus
13. cells that enclose their DNA in nuclei
15. a large membrane-enclosed structure that contains genetic material in the form of DNA
17. the structures inside a cell that act like “little organs”