Revision from AS OCR Biology (F212)

1. Eukaryotic Cells

2. Nucleus
- Largest organelle
- Contains chromosomes  make most of DNA
- Chromatin  heterochromatin and
euchromatin
- mRNA exits through pores (for
proteinsynthesis)
- Nucleolus forms ribosomes

3. Cell Membrane
- Boundary  controls what molecules enter
and exit a cell
- Phospholipid bilayer structure
- Permeable to O2 and CO2
- Impermeable to H2O and charged molecules

4. Cytoskeleton
- Maintains the structure and shape of the cell
- Allows motion and helps transport organelles
within the cell
- Made of microfilaments, intermediate
filaments and microtubules

5. Endoplasmic Reticulum
Rough ER
- Ribosomes (protein+RNA) on surface 
proteinsynthesis occurs
- Transports proteins from ribosomes to the golgi
apparatus
Smooth ER
- No ribosomes on surface
- Lipid synthesis

6. Mitochondrion
- Smooth outer membrane
- Folded inner membrane
- Aerobic respiration

7. Lysosomes
- Membrane bound vesicles
- Contain digestive enzymes (proteins)
- Digest engulfed bacteria/virus/waste
- Formed from golgi apparatus

8. Golgi Apparatus
- Flattened sacs
- Stacks of membranes
- Process & Packages proteins  glycosylated;
adding sugars)

9. Prokaryotic Cells

10. Structures
Pilli
Circular DNA
Ribosomes
Flagellum
Cell wall
Cytoplasm
Mesosome

11. Functions
- Movement from  flagella
- Proteinsynthesis from  ribosomes
- Attachment/DNA transfer  pilli
- Enzymes for metabolism  cytoplasm
- Entry and exit  plasma membrane

12. Prokaryote Eukaryote
Small; unicellular Larger; multi or unicellular
No nucleus; circular DNA Nucleus; linear DNA
Small ribosomes (70s) Large ribosomes (80s)
No mitochondria- respiration in
mesosomes and cell membrane
Mitochondria for aerobic
respiration
Binary fission- division Meiosis/Mitosis- division
Asexual reproduction Sexual and asexual reproduction