7 2 Biology Notes

7-2 Notes
Eukaryotic Cells
1. Eukaryote cells are divided into two parts
Nucleus
Cytoplasm
Portion outside the nucleus where organelles reside
Nucleus
2. Contains most of the cell’s DNA
3. DNA is the code for making proteins
4. Surrounded by a double membrane called the nuclear envelope
5. Contains chromatic, which consists of DNA bound to protein
Condenses during cell division to form chromosomes
6. Nucleolus – small dense region in nucleus where the assembly of ribosomes begins
Ribosomes
7. Small particles of RNA and protein
8. Are spread throughout the cell
9. Are also attached to the rough endoplasmic reticulum
10. Ribosomes are the site of protein synthesis
Endoplasmic Reticulum
11. An internal membrane system
12. Lipids, some proteins, and other materials are assembled here
13. Rough ER has ribosomes attached to allow for protein synthesis
14. Smooth ER has no ribosomes to allow for lipid synthesis
Golgi Apparatus
15. Appears as a stack of membranes
16. Acts like a postman
17. It changes, sorts, and packages proteins and other materials
18. Also delivers these “packages” to their final destination
Lysosomes
19. Small organelles filled with enzymes
20. Act as a cleaning crew
21. They break down lipids, carbohydrates, and proteins so the cell can use them
22. Also break down “old” organelles
23. Also break down unneeded junk in the cell such as bacteria
Vacuoles
24. Saclike structure used for cell storage
25. Stores water, salts, proteins and carbohydrates
Mitochondria
26. “powerhouse of the cell”
27. Converts chemical energy stored in food into a form that cells can use
28. Has a double membrane
29. One on the outside of the organelle
30. One folded up inside the organelle
31. Contains its own DNA
Chloroplasts
32. “powerhouse for a plant cell”
33. Converts energy form sun into chemical energy during processes of photosynthesis
34. Contains its own DNA
Cytoskeleton
35. A network of protein filaments
36. Helps cell retain its shape
37. Also helps in cell movement
38. Two of the filaments are microfilaments and microtubules
39. Microtubules are very important in cell division
40. As well as centrioles which help organize cells

Short Answer Questions
1. Compare and contrast the structure and function of the cell wall with that of the cell membrane.
Compare: Both provide protection and support for the cell Contrast: Wall found only in plants, fungi and algae. Usually rigid and lies on the outside of the membrane, membrane is soft and flexible made of a lipid bilayer.
2. What are 2 functions of the Nucleus?

1. Control center of the cell 2. Contains all DNA

3. Identify 2 jobs of the cytoskeleton
1. Maintains cell shape 2. Cell movement