3.  2.3.1: Draw and label a diagram of the ultrastructure of a liver cell as an example of an animal cell  2.3.2: Annotate the diagram with the functions of each named structure  2.3.3: Identify structures from 2.3.1 in electron micrograph of liver cells  2.3.4: Compare prokaryotic and eukaryotic cells  2.3.5: State three differences between plant and animal cells  2.3.6: Outline two roles of extracellular components

4.  Eukaryotic cells range in size: 5 to 100 µm (in diameter)  Most noticeable organelle: nucleus  Others can be noticeable with high enough resolution

5.  Organelles: are non-cellular structures that carry out specific functions  Organelles found in cell vary with the type of cell  Organelles bring out compartmentalization ▪ Allows chemical reactions to be separated (important because some chemical reactions are not compatible with others)  NOT in prokaryotic cells

6.  Common organelles:  Endoplasmic Reticulum (ER)  Ribosomes  Lysosomes (not usually in plants)  Golgi apparatus  Nucleus  Chloroplasts (only in plant and algal cells)  Centrosomes ▪ Centrioles (type of centrosomes—not in plants)  Vacuoles

7.  Cytoplasm-not an organelle but a region  All organelles occur within  The fluid part between the organelles is referred as the cytosol

8.  Endoplasmic Reticulum  Extensive network of tubules or channels that extend almost everywhere in the cell from the nucleus to the plasma membrane ▪ Enables the function of transportation of materials throughout the internal region of the cell  Two general types ▪ Smooth and Rough

9.  Endoplasmic Reticulum (Smooth)  Has no ribosomes attached to it  Has many unique enzymes embedded on its surface ▪ Function: ▪ Production of membrane phospholipids and cellular lipids ▪ Production of sex hormones such as testosterone and estrogen ▪ Detoxification of drugs in the liver ▪ Storage of calcium ions needed for contraction in muscle cells ▪ Transportation of lipid-based compounds ▪ To aid the liver in releasing glucose into the bloodstream when needed

10.  Endoplasmic Reticulum (Rough)  Has ribosomes on the exterior of the channels  Ribosomes involved in protein synthesis  Function: ▪ Protein development and transport  Most cells contain both types of ER with the rough being closer to the nuclear membrane

11.  Ribosome  Not have a exterior membrane  Function: Protein synthesis  Can be found free (in cytoplasm) or attached (ER)  Found in both Eukaryotic and Prokaryotic cells ▪ Ribosomes found in eukaryotic cells are larger and denser then ones in prokaryotic cells ▪ All ribosomes contain 2 subunits ▪ Eukaryotic: 80S ▪ Prokaryotic 70S

12.  Lysosomes  Intracellular digestive centers (come from Golgi )  No internal structures  They are sacs bounded by a single membrane but contain as many as 40 different hydrolytic enzymes (very acidic)  Function: Fuse the old or damaged organelles from within the cell to break them down so that recycling of the components may occur ▪ Also involved breakdown of materials brought into cell by phagocytosis

13.  Golgi Apparatus  Consists of flattened sacs called cisternae (stacked on top of eachother)  Functions: in collection, packaging, modification, and distribution of materials synthesized in cell ▪ Cis side-near ER, to receive product ▪ Move into the cisternae of the Golgi ▪ Trans side-product is discharged from ▪ small sacs called vesicles are released from this side  These carry modified materials to wherever they are needed inside and outside the cell

14.  Mitochondria  Rod shaped organelle that appear throughout the cytoplasm (same size as a bacterial cell)  Has their own DNA, circular  Double Membrane-Outer (smooth), Inner (Folded into cristae) ▪ Inside the inner membrane is a semi-fluid substance called matrix ▪ Inner membrane spaces-lies between the two membranes

15.  Mitochondria-Function  The cristae provides huge internal surface area for chemical reactions to occur ▪ Most chemical reactions involve the production of usable cellular energy-ATP  Contains its own ribosomes (70S type)  Cells that have high energy requirements, such as muscle cells, have a large numbers of mitochondria

16.  Nucleus-is an isolated region where the DNA resides  Bordered by a double membrane referred to as the nuclear envelope ▪ Allows for separation for the DNA—providing an area where DNA can carry out its functions and not be affected by the other parts of a cell ▪ DNA (genetic material) is usually found in a form of chromosomes ▪ Carry all the information necessary for the cell to exist (allows for survival) ▪ DNA is only found in the form of chromatin during cellular division (formed from histones and DNA (nucleosome) ▪ Nucleosome consists of 8 histones with a DNA wrapped around them

17.  Nucleus  Usually located centrally in the cell  Most cells only contain one!  Cannot reproduce without a nucleus ▪ Only found in very specialized cells (example: blood)  Nucleolus: dark area inside the nucleus ▪ Function of nucleolus: production of ribsomes

18.  Chloroplast  Only occurs in plant and algae cells  Double membrane and is about the size of a bacterial cell ▪ Contains its own DNA (circular) and 70S ribosomes  Also contains granum, thylakoid, and stroma ▪ Granum-is made up of numerous thylakoids stacked in a pile ▪ Thylakoid-are flattened membrane sacs with components necessary for absorption of light ▪ Stroma-similar to cytosol: occurs outside the grana but within the double membrane (contains enzymes and chemicals necessary to complete photosynthesis

19.  Centrosome  Occurs in all eukaryotic cells ▪ Consists of a pair of centrioles at a right angle to one another ▪ Involved in assembling microtubules (important for movement, structure, and cell division) ▪ Plants do not have centrioles but the centrosome is located at one end of the cell close to the nucleus

20.  Vacuoles-are storage organelles that usually form from the Golgi Apparatus  Membrane bound and have many possible functions  Plant cells-occupy VERY large area inside the cell ▪ Allows an uptake of water that provides rigidity  Function: storage of number of different substances including potential food, metabolic wastes and toxins, and water ▪ Enable cells to have higher surface area to volume ratio

21. Prokaryotic CellsEukaryotic Cells DNA in a ring form without protein DNA with proteins as chromosomes/chromatin DNA free in the cytoplasm (nucleoid region) DNA enclosed within a nuclear envelope (nucleus) No mitochondriaMitochondria present 70S ribosome80S ribosome No internal compartmentalization to form organelles Internal compartmentalization present to form many types of organelle Size less than 10 µmSize more than 10 µm

22.  Similarities:  Both types of cells have some sort of outside boundary that always involves a plasma membrane  Both types of cell carry out all the functions of life  DNA is present in both cell types

23. Plant cellsAnimal Cells Exterior of cell includes an outer cell wall with a plasma membrane just inside Exterior of cell includes only a plasma membrane. There is not cell wall Chloroplasts are present in the cytoplasm There are not chloroplasts Possess large centrally located vacuoles Vacuoles are usually not present or Very small Store carbohydrates as starchStore carbohydrates as glycogen Do not contain centrioles within a centrosome area Contain centrioles within a centrosome area Because a rigid cell wall is present, this cell type has a fixed, often angular, shape Without cell wall, this cell is flexible and more likely to be rounded shape

24.  The outermost region of various cell types is often unique: CellOutermost part BacteriaCell wall of Peptidoglycan FungiCell wall of Chitin YeastsCell wall of glucan and mannan AlgaeCell wall of cellulose PlantsCell wall of cellulose AnimalsNo cell wall: plasma membrane secretes a mixture of sugar and proteins called Glycoproteins that form the extracellular matix

25.  Extracellular matrix (ECM): composed of collagen fibers plus a combination of sugars and proteins called glycoproteins  Fiber-like structures that anchor the matrix to the plasma membrane—strengthens the plasma membrane and allows attachment between adjacent cells  ECM allows for cell to cell interaction (many researchers believe it is involved in directing stem cells to differentiate)