KEY CONCEPT Eukaryotic cells share many similarities.

1. KEY CONCEPT Eukaryotic cells share many similarities.

2. Cells have boundaries The Plasma Membrane •Forms a boundary between a cell and the outside environment • Controls the passage of materials into and out of the cell • Helps to maintain homeostasis

3. Wastes Oxygen Invaders CO2 Wastes Water Glucose • Cells have boundaries • The plasma membrane is selectively permeable - allows some, but not all materials to cross Outside the Cell Inside the Cell

4. Cells have boundaries Structure of the Plasma Membrane • Composed of a phospholipid bilayer

5. Cells have boundaries Other components in the Plasma Membrane Proteins • some span the entire membrane and help materials cross • others are found on the inner and outer surface – anchoring

6. Cells have boundaries Other components in the Plasma Membrane • Cholesterol – strengthen the membrane • Carbohydrates – cell identification

7. Cells have boundaries • The Plasma membrane is referred as the fluid mosaic model *Fluid - flexible *Mosaic - pattern

8. Cells have boundaries The Cell Wall • A rigid structure located just outside of the plasma membrane • Found in plants, fungi, most bacteria, and some protists • Provides protection and support • It is not selectively permeable • In plants, it is composed of cellulose

9. Cells have an internal structure. • The Cytoskeleton • A network of protein fibers that crisscross the entire cell • Three types of fibers • a) Microtubules • b) Intermediate filaments • c) Microfilaments

10. Cells have an internal structure. • The cytoskeleton has many functions. • supports and shapes cell • helps position and transport organelles • provides strength • assists in cell division • aids in cell movement

11. Cells have an internal structure. The Cytoplasm • Fills the space between the nucleus and cell membrane • Consists of organelles and cytosol(mostly water)

12. Several organelles are involved in making and processing proteins. The Nucleus • Storehouse of DNA • Surrounded by a nuclear membrane • Nuclear pores allow large molecules to pass between the nucleus and the cytoplasm • The nucleolus is where ribosomes are produced

13. Several organelles are involved in making and processing proteins. The Endoplasmic Reticulum •An interconnected network of folded membranes • Important in synthesis and transport of cellular materials • Two types – Rough ER and Smooth ER

14. Several organelles are involved in making and processing proteins. Rough Endoplasmic Reticulum • Has ribosomes attached • Proteins are made by the ribosomes on the surface, and then move inside the rough ER to be packaged into a vesicle • The vesicle then takes the protein to the Golgi Apparatus

15. Several organelles are involved in making and processing proteins. Ribosomes • The site of protein synthesis • Can be found attached to Rough ER or free in the cytoplasm

16. Several organelles are involved in making and processing proteins. Smooth Endoplasmic Reticulum • No ribosomes attached • Produces lipids • Detoxification of drugs and poisons

17. Several organelles are involved in making and processing proteins. The Golgi Apparatus • Closely layered stacks of membrane – enclosed spaces • Modifies, packages, and transports proteins • The vesicles can then be stored, transported, or secreted

18. Some organelles transform energy in the cell Mitochondria • Bean shaped organelle with a double membrane • Produces ATP through cellular respiration • The cell uses the ATP for energy • Mitochondria have their own ribosomes and DNA WHY?? C6H12O6 + 6 O2 = 6 CO2 + 6 H2O + ATP

19. Some organelles transform energy in the cell The Chloroplast • Organelles that carry out photosynthesis • Found in plant cells • Has two membranes • Contains chlorophyll which absorbs light and gives plants their green color • Also have their own DNA and ribosomes 6 CO2 + 6 H2O + Light = C6H12O6 + 6 O2

20. Other organelles have various functions. Vacuoles • A membrane bound sac used for storage Ex – water, food molecules, and enzymes • Plant cells have one large vacuole • Animal cells have many small vacuoles

21. Other organelles have various functions. The Lysosome • Membrane bound organelle that contains digestive enzymes • Digests worn out organelles, food particles, and engulfed viruses or bacteria • Numerous in animal cells • Their presence in plant cells is still questioned by some scientists

22. Other organelles have various functions. Centrosome and Centrioles • The centrosome is a small region of the cytoplasm that produces microtubules • In animals, it contains a pair of centrioles • Centrioles help DNA divide during cell division

23. Other organelles have various functions. Cilia Flagella • Short, numerous hair-like projections • Move in a wave-like motion • Used for feeding and locomotion • Long projection • Moves in a whip-like motion • Used for locomotion