1. Cell Structure and Function Donald Winslow, St. Gregory’s University 20 January 2014 Sources: Mader, Sylvia 2011. Inquiry into Life, 13 th ed., McGraw-Hill, NY. Alberts, et al. 2008. Molecular Biology of the Cell, 5 th ed., Garland, NY.

2. Objectives List organelles found in most cells. Describe structure & function of these organelles. Give examples of cells where particular types of organelles are abundant. Describe structure & function of cell membranes. Contrast cell membranes & cell walls. Explain membrane transport processes.

3. Organelles in an endothelial cell

4. Nucleus Envelope (2 membranes) Functions in DNA replication & RNA synthesis Most eukaryotic cells have one nucleus. Syncytial eukaryotic cells have multiple nuclei. Prokaryotic cells do not have nuclei.

5. Mitochondria & chloroplasts Mitochondria  Inner membrane & outer membrane  Function in cellular respiration  Especially abundant in muscle cells Chloroplasts  Inner membrane & outer membrane  Function in photosynthesis  Especially abundant in leaf cells

6. Endoplasmic reticulum One membrane surrounding lumen Lipid bilayer synthesis, transport to membranes Rough endoplasmic reticulum (with ribosomes)  Proteins imported into ER as they are made Smooth endoplasmic reticulum

7. Ribosomes No membranes 2 subunits composed of protein & RNA Protein synthesis from info in messenger RNA Especially abundant in cells that secrete proteins

8. Lysosomes & peroxisomes Lysosomes  One membrane  Intracellular digestion Peroxisomes  One membrane  Oxidation of toxins by peroxide  Especially abundant in protective tissues

9. Golgi apparatus Stack of membrane-bound “pancakes” Staging area for ER products

10. Vesicular transport Transport vesicle

11. Cell membranes Phospholipid bilayer with embedded proteins Hydrophobic & hydrophilic ends of phospholipids Hold cytoplasm in cell, flexible shape Selective transport of materials across membranes Physical & physiological mechanisms

12. Cell membrane

13. Physical transport mechanisms Diffusion Osmosis

14. Physiological transport mechanisms Facilitated diffusion Active transport Bulk transport Phagocytosis Pinocytosis

15. Cell walls Found in plants, fungi, bacteria, archaea Made of carbohydrates Rigid