1. Eukaryotic Cell Structure
Chapter 7.3

2. Cellular boundaries Plasma Membrane/Cell Membrane
Fxn-acts as a selectively permeable membrane

3. The Cell Wall
Cell Wall-def-pg.179-a fairly rigid structure located outside the plasma membrane that provides additional support and protection-ONLY IN PLANT CELLS, FUNGI, BACTERIA!!!!
Fxn: Cell wall forms an inflexible barrier that protects the cell & gives it support
Composed of cellulose, which forms a thick, tough mesh of fibers & is porous to allow molecules to enter the cell

4. The Nucleus and Cell Control
Nucleus Fxns:
Nucleus of cell contains the directions to make proteins  the leader of eukaryotic cells
Nucleus controls all the activities of the organelles
Chromatin-def-pg.180- the master set of directions for making proteins-which are strands of DNA (genetic material)
when the cell divides chromatin condenses  forms chromosomes
Nucleolus
A prominent organelle within the nucleus
Fxn: makes ribosomes

5. The Nucleus and Cell Control
Ribosomes
Ribosomes-def-pg.181-are the sites where the cell produces proteins according to the directions of DNA
Fxn: synthesis of proteins
Can be found free floating in cytoplasm & make proteins that perform tasks w/in the cytoplasm
Ribosomes have a simple structure, composed of:
RNA
Protein
Not bound by membranes

6. The Nucleus and Cell Control
How ribosomes make proteins?
(1) The DNA (the blueprints) within the ribosomes must be translated into RNA then transported to the cytoplasm
(2)The RNA and the ribosomes are then transported via the nuclear pores through the nuclear envelope into the cytoplasm
Nuclear envelope-def-pg.181- the structure that separates the nucleus from the cytoplasm, made of a double membrane of 2 phospholipid bilayer containing small nuclear pores for substances to pass through
Cytoplasm-def-pg181-the clear, gelatinous fluid inside a cell, in which the cell’s organelles are suspended
Once the RNA and the ribosomes are in the cytoplasm the proteins can be produced.

7. Assembly, Transport, and Storage
i) Organelles for assembly and transport of proteins
Endoplasmic reticulum-def-pg.181- the site of cellular chemical reactions, and it is arranged in a series of highly folded membranes in the cytoplasm
Fxn: the site of cellular chemical reactions

8. Assembly, Transport, and Storage
Rough ER-def-pg181- ribosomes in the cytoplasm which are attached to the surface of the endoplasmic reticulum (ER).
Fxn: protein synthesis & modifies proteins
Each protein made in the rough ER has a particular function
Ex/
protein that forms part of the cell membrane
a protein released from the cell
protein transported to another organelle

9. Assembly, Transport, and Storage
Organelles for assembly and transport of proteins
Smooth ER-def-pg182-areas of the ER that are not studded with ribosomes
Fxn: Involved in numerous biochemical rxns (i.e. production and storage of lipids)
Golgi Apparatus-def-pg.182-a flattened stack of tubular membranes that modifies the proteins.
Fxn: sorts proteins into packages and packs them into membrane bound structures call vesicles (like a post office)

10. Assembly, Transport, and Storage
Rough and Smooth Endoplasmic Reticulum

11. Assembly, Transport, and Storage
Golgi
Bodies/Apparatus

12. Vacuoles and storage
Vacuoles-def-pg183-membrane bound compartments, which are larger than vesicles used for temporary storage of materials:
Sacs used to store:
Food
Enzymes
other materials needed by a cell
waste products
Animal cells usually don’t contain vacuoles

13. Vacuoles and storage Plant vacuoles usually contain: Water Sugar Salts
Water-soluble pigments
Toxic molecules
Central Vacuole-def- found only in plant cells, large central vacuoles are filled with sap which gives the cell added support

14. Lysosomes and recycling
Lysosomes-def-pg183-organelles that contain digestive enzymes
Fxn: digest excess or worn out organelles, food particles, and engulfed viruses or bacteria
Lysosome Membrane fxn:
Membrane prevents the digestive enzyme inside the lysosomes from destroying the cell
How lysosomes work?
Lysosomes fuse with vacuoles & dispense their enzyme into the vacuoles digesting its contents
Ex/Amoeba

15. Energy Transformers Cell organelles require great of energy for:
Protein production & modifications,
Protein transportation & digestion
2 organelles that provide energy:
Chloroplasts (in plants)
Mitochondria (in animals)

16. Chloroplasts and energy
Chloroplast-def-pg.184-organelles that capture light energy and convert it to chemical energy
Fxn-organelle where photosynthesis is done in a plant cell
Chloroplasts have double membranes
Thylakoid membranes trap the energy from sunlight & are arranged in stacks of membranous sacs called grana and surrounded by fluid called stroma
Plastid-def-pg.184-grp of plant organelles used for storage (i.e. starches/lipids) or may contain pigments
Chlorophyll-def-pg.184-traps light energy and gives leaves and stems their green color

17. Mitochondria and energy
Chemical energy generated by chloroplasts is stored in the sugar molecules until it is broken down by the mitochondria
Mitochondria-def-pg185- are membrane-bound organelles in plant & animal cells that transform energy for the cell.
Fxn of mitochondria-energy that the cell doesn’t use is put into easily accessible bonds so it can be used when energy is needed.
Structure of Mitochondria- has an outer membrane & a highly folded inner membrane
Inner membrane provides lrg surface area that can fit into a sm space & energy-storing molecules are produced there
Mitochondria occur in varying numbers depending on the cell function

18. Organelles for Support
Cytoskeleton-def-pg.185-support structure within the cytoplasm
The Cytoskeleton
Cytoskeleton can be dismantled & reassembled= cell’s shape changes
Composed of a network of:
Microtubules-def-pg185- thin, hollow cylinder made of proteins
Microfilaments-def-pg185-smaller, solid protein fibers
Fxn-
Maintain shape of cell
Anchor & support many organelles
Provide a highway system through which materials move within the cell

19. Organelles for Cell Division
Centrioles
Found in animal and protist cells
Occur in pairs
Made up of microtubules
Fxn-play an important role in cell division

20. Organelles for Locomotion
Cilia and flagella
Cells can have cilia or flagella which are made up of microtubules that help with locomotion (moving) & feeding
Cilia-def-pg.187-short, numerous projections that look like hairs
Flagella-def-pg187-longer projections that move with a whiplike motion
Cells usually has only 1 or 2 flagella