1. Cells (Prokaryotic & Eukaryotic) w There are two types of cells Prokaryotes and Eukaryotes w Prokaryotes cells that lack membrane-bound organelles. Bacteria are the only organism to have prokaryotic cells. Prokaryote Cell

2. A prokaryotic cell does not have internal organelles surrounded by a membrane. Most of a prokaryote’s metabolism takes place in the cytoplasm. 1. Ribosomes 2. DNA 3. Plasma membrane 4. Cell wall Click here to return to chapter summary Chapter Assessment

3. Eukaryotes w Eukaryotes have a higher level of complexity. w Eukaryotic Cells contain organelles that are bound by membranes. w All cells other than bacteria are Eukaryotic cells

4. This eukaryotic cell from an animal has distinct membrane-bound organelles that allow different parts of the cell to perform different functions. 4. Plasma membrane 1. Nucleus 2. Nucleolus 3. Chromosomes 5. Organelles Chapter Assessment

5. Components of Cells w Cell Membrane - functions as semi- permeable barrier. Allowing a few molecules across it while fencing the majority of organically produced chemicals inside the cell.

6. Cell Walls w The Cell Wall is a structure surrounding the cell membrane. w Cell Walls contains cellulose that makes the cells more ridged. w Plants and Plant-liked organisms have cell walls

7. The Plasma Membrane

8. Cytoplasm w The cytoplasm is defined as the material between the cell membrane and the nucleus of a cell. w A semi-gel fluid that helps moves substances in a cell.

9. Organelles w Organelles are formed bodies within the cytoplasm that perform certain functions in a cell. w Examples include: nucleus, ribosomes, endoplasmic reticulum, mitochondria.

10. Nucleus /Nucleolus/Nuclear membrane or envelope w The nucleus controls the functions of the cells w The nucleus is found only in eukaryotic cells. w The nucleolus found in the nucleus is where nucleotides are constructed, begins the assembly of ribosomes.

11. Nuclear membrane (con’t) w The nuclear membrane or sometimes called the nuclear envelope is a double-membrane structure.. Numerous pores occur in the envelope, allowing RNA and other chemicals to pass, but not DNA.

12. Chromosomes w Chromosomes are found in the nucleus. They may appear as “Xs”. w Chromosomes contain the hereditary material of DNA which control all cell activities. w Chromosomes are able to replicate or reproduce.

13. Centrioles w Play a major role in cell reproduction only found in animal cells. w Generally only seen during cell division w May look like a long cylindrical asterisk in most models

14. Cytoskeleton w The cytoskeleton is a network of protein filaments that helps the cell to maintain its shape. The cytoskeleton is also involved in movement.

15. Vacuoles w Vacuoles are usually a storage area and recycling site. w Vacuoles usually appear larger in plant cells than in animal cell. Plant Cell Animal Cell

16. Ribosomes w Ribosomes are the sites of protein synthesis w Some ribosomes are free floating some are attach to endoplasmic reticulum.

17. Endoplasmic Reticulum w Rough and Smooth Endoplasmic Reticulum w Rough ER Serves the function of storing and transporting proteins. w Rough ER is so named because of its rough appearance due to the numerous ribosomes that occur along the ER. w Smooth ER contains collections of enzymes that perform tasks such as synthesizing membrane lipids and the detoxifications of drugs. Named because it does not have ribosomes attached to it

18. Mitochondria w Mitochondria function as the sites of energy production. w The mitochondria has been termed the “powerhouse” of the cell.

19. Golgi Apparatus w Golgi bodies are flattened stacks of membrane-bound sacs (looks likes pancakes). w They function as a packaging plant, for carbohydrates and proteins.

20. Lysosomes w Lysosomes are the “disposal units” of cells w Lysosomes function in the extracellular breakdown of materials. w Generally found only in animal cells.

21. Plastids (Chloroplast, Leucoplast, & Chromoplasts) w Chloroplast - are the sites of photosynthesis in eukaryotes. w They contain chlorophyll, the green pigment necessary for photosynthesis

22. Leucoplast w Leucoplast- stores starch. w Leucoplast are most likely found in the roots tissue of most plant. Example: potato

23. Chromoplast w Stores pigments associated with the bright colors of flowers and or fruits.

24. Cilia & Flagella w Cilia and Flagella are similar except for length, cilia being much shorter (hair- like). Flagella are long whip-like. w Both are responsible for movement. Cilia on a paramecium Flagella on a Euglena