1. Cell Review

2. Cells The Cell Theory All living things are made of one or more CELLS.
Cells are the basic unit of structure and function in an organism.
New cells are produced from existing cells.

3. 2 types of cells Prokaryotes Eukaryotes
Cells without a nucleus or organelles surrounded by membranes
Eukaryotes
Cells with a nucleus and organelles surrounded by membranes.

4. Prokaryotes Single celled organism
Has DNA that is circular floating all around in the cytoplasm
Only has ribosomes and no other membrane bound organelles
Most common = bacteria
Some can make their own food, most get food from other sources

5. Eukaryotes
There can be singled celled eukaryotes as well as multicellular
Highly organized
More complex than prokaryotes

6. Cell membrane (plasma membrane)
Made mainly of phospholipids (2 layers) and proteins
Outside
of cell
Inside
(cytoplasm)
Cell
membrane
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains

7. Cell membrane made of:
Phospholipids have hydrophobic tails made of lipids and hydrophilic heads.
3 kinds of proteins-
channel-provides a path for materials to move in and out
marker- used for recognition
receptor- receive signals

8. Cell membrane Acts as a boundary Controls what enters and leaves cell
Fluid (fluid mosaic model)
Molecules in cell membranes are constantly moving and changing (ex. cholesterol and carbohydrates)

9. Nucleus LARGEST organelle in animal cells
Surrounded by nuclear envelope
Contains nuclear pores = openings that allow molecules to move in and out of nucleus
Contains genetic material (DNA)
Control center of the cell

10. Nucleolus
Dark spot in nucleus
Assembles RNA and also ribosomes

11. Cytoskeleton Helps cell maintain shape Help move organelles around
Made of proteins
Microfilaments
Microtubules

12. Centrioles Made of microtubules
Only seen in animal cells during cell division
Function: Guide chromosomes during PMAT

13. Mitochondria “Powerplant of cell” Site of cellular respiration
Burns glucose to release energy
Stores energy as ATP
Surrounded by double membrane
Inner membrane = cristae

14. Ribosomes Can be free in cytoplasm or attached to rough ER
Made of rRNA
Function: assembles proteins
Called the site of protein synthesis

15. Endoplasmic reticulum (internal network of membranes)
Rough ER
Attached ribosomes make proteins which are modified and transported to Golgi for export
Smooth ER
Makes membrane lipids (steroids)
Regulates calcium in muscles
Breaks down toxins in liver

16. Golgi Apparatus Looks like a “stack of pancakes” Made of membranes
Modify, sort, and package substances from ER for storage or export out of cell

17. Lysosomes Sac containing digestive enzymes
Digests food molecules and unwanted cells/cell parts
Plays a role in apoptosis “programed cell death”
Cell suicide for the good of the organism

18. Movement
Pseudopodia = “false feet” help amoebas with movement and eating (phagocytosis)
Cilia = many and short
microtubules (little hairs)
Move cells
Move substances past cells
Flagella = few and long
microtubules (like a tail)

19. What’s special about plant cells?
Cell wall
HUGE central vacuole
Chloroplasts
No centrioles!!

20. Cell wall Found outside the cell membrane
Provides support and protection
Made of Cellulose (carbohydrate) makes plant sturdy
Bacteria have cell walls made of peptidoglycan instead
Cell walls of fungi are made
of chitin

21. Vacuoles Storage space for: proteins, carbohydrates, water, waste
Contractile vacuoles control excess water in a paramecium (homeostasis)
Huge in plant cells, small animal cells, not in bacteria

22. Chloroplast Surrounded by double membrane
Thylakoids = membrane sacs inside
Contains chlorophyll where photosynthesis happens
Found photosynthetic cells (plants, some
bacteria and protozoans)

23. Molecule Movement and Cells
Passive Transport = does not require energy by the cell
Active transport = requires energy!

24. Passive transport No energy required Move due to gradient
Differences in concentration, pressure, charge
Move to equalize gradient (equilibrium)
High concentration moves toward low concentration
3 Types
Diffusion, osmosis, facilitated diffusion

25. Diffusion
Molecules move to equalize concentration

26. Osmosis Special form of diffusion
Fluid flows from lower solute concentration
Always involves movement of water
Into cell
Out of cell

27. Hypotonic = solutes in cell more than outside, fluid will flow into cell

28. Isotonic = solutes equal inside and out of cell

29. Hypertonic = solutes greater outside cell, fluid will flow out of cell

30. Facilitated Diffusion
Channels (are specific) help molecule or ions enter or leave the cell
Channels usually are transport proteins

31. Active transport Molecular movement Requires energy (against gradient)
Example: sodium-potassium pump

32. Endocytosis
Phagocytosis – cell eating
Pinocytosis – cell drinking

33. Exocytosis
Reverse of endocytosis
Cell discharge material

34. Cellular reproduction
5 ways
1. Fission
2. Budding
3. Vegetative propagation
4. Mitosis
5. Meiosis

35. Binary Fission Prokaryotes (bacteria) Asexual reproduction
Cell makes copy of DNA and grows in size
Membrane will divide and two new cells formed

36. Budding Asexual reproduction Hydra bud to form new hydra
Yeast cells undergo budding

37. Vegetative propagation
Asexual reproduction in plants
Runners will grow off from the parent plant and root to form a new identical plant.