1. Chapter 6 A Tour of the Cell

2. Things to Know The differences between eukaryotic and prokaryotic cells The structure and function of organelles common in plant and animal cells The structure and function of organelles found only in plant or animals cells

3. Prokaryotes vs. Eukaryotes CharacteristicsProkaryotesEukaryotes Plasma MembraneYes Cytosol with organellesYes RibosomesYes NucleusNoYes Size1-10 µm (micrometer)10-100µm Internal membranesNoyes prokaryotes include domains Bacteria and Archaea eukaryotes belong to the domain Eukarya and include animal, fungi, plants, and protists

4. Prokaryotes vs. Eukaryotes 3 things about Prokaryotes - chromosomes are grouped in area called nucleoid (no nucleus) - no membrane-bound organelles (ribosomes are present, but are not membrane bound) - much smaller than Eukaryotes 3 things about Eukaryotes - has membrane bound nucleus - many membrane-bound organelles in cytoplasm - average larger than Prokaryotes

5. Plasma Membrane -the plasma membrane forms the boundary for the cell - Selectively permeable (allowing only some materials in/out - Made up of phospholipids; with proteins and carbs throughout - referred to as “fluid mosaic” model

6. Nucleus The nucleus contains the cell’s DNA - Surrounded by a double membrane, nuclear envelope - nuclear envelope contains nuclear pores (holes) that control enter and leaving nucleus - chromatin is the DNA and protein complex inside (used in cell division) - nucleolus is the region inside where RNA is made

7. Ribosomes Ribosomes are sites of protein synthesis - consist of large and small subunit - may be free floating (when making proteins for the cell or bound to endoplasmic reticulum (making proteins for export)

8. Endoplasmic Reticulum the endoplasmic reticulum (ER) is a network of membranes - smooth ER has 3 functions; synthesis of lipids, metabolism of carbohydrates, and detox from drugs and poisons - rough ER has ribosomes attached and are sites where protein is made and distributed to the golgi apparatus for export

9. Golgi Apparatus Proteins made by ribosomes on the ER are stored in transport vescicles and shipped to the golgi apparatus. The golgi apparatus is the site where the proteins are modified, stored, and shipped out of the cell Cisternae: flattened membranous sacs making up Golgi trans face (shipping) & cis face (receiving)

10. Mitochondria Mitochondria is the site where cellular respiration occurs ATP is created from mitochondria, so it’s usually referred to as the “powerhouse” Mitochondria are enclosed by double membrane and has inner membranes with folds called cristae

11. Peroxisomes Peroxisomes are single-membrane bound Responsible for metabolic functions that involve transferring hydrogen to oxygen (producing H2O2) Responsible for breaking down fatty acids to fuel the mitochondria

12. Cytoskeleton Cytoskeleton is a network of fibers that run throughout the cell for support, motility, and regulating activities 3 types of fibers - microtubules is made of protein and it’s the largest fiber - microfilaments is composed of protein actin and it’s the smallest fiber - intermediate filaments are permanent medium sized fibers

14. Centrosomes Centrosomes are regions located near the nucleus, where microtubules grow

15. Found only in animal Cells Lysosomes contain enzymes that digest macromolecules Centrioles are located in centrosomes and are important in cell division 2 types of microtubles -flagella is a long tail used to help cell propel through water (unicellular) - cilia are “hairs” that also help cell move 3 types of intercellular junctions (connections to neihbor cells) - tight junctions are when two cells are fused together making it water- tight - desmosomes fasten neighbor cells together, like nails - gap junctions are channels or hole where the two neighboring cells can exchange molecules

16. Extra Cellular Matrix (ECM) -Glycoproteins - proteins covalently bonded to carbohydrate -Collagen (50% of protein in human body); embedded in proteoglycan (another glycoprotein-95% carbohydrate) -Fibronectins - bind to receptor proteins in plasma membrane called integrins (cell communication) Found only in animal Cells

17. Found only in plant cells central vacuole are organelles that store and breakdown some waste products. Plants have vacoule about 80% of their size Chloroplast are in plant and algae cells and are the sites of photosynthesis the cell wall protects and supports plant cells and are made of cellulose Plasmodesmata are channels that allow plant cells to exchange material with their neighbors