1. Chapter 4

2. Most Cells Are Microscopic

3. Effect of Cell Size on Surface Area

4. Scanning & Transmission Electron Microscopes

6. Prokaryotic cells are structurally simpler than eukaryotic cells

7. Eukaryotic cells are partitioned into functional compartments Human cells have three basic parts: Plasma membrane—flexible outer boundary Cytoplasm—intracellular fluid containing organelles Nucleus—control center

8. Smooth endoplasmic reticulum Rough endoplasmic reticulum CYTOSKELETON: NUCLEUS: Nuclear envelope Chromosomes Nucleolus Ribosomes Golgi apparatus Plasma membrane Mitochondrion Peroxisome Centriole Lysosome Microtubule Intermediate filament Microfilament

9. Smooth endoplasmic reticulum Rough endoplasmic reticulum CYTOSKELETON: NUCLEUS: Nuclear envelope Chromosome Nucleolus Ribosomes Golgi apparatus Plasma membrane Mitochondrion Peroxisome Cell wall Central vacuole Microtubule Intermediate filament Microfilament Cell wall of adjacent cell Chloroplast Plasmodesmata

10. Plasma Membrane Bimolecular layer of lipids and proteins Constantly changing Dynamic role in cellular activity Separates intracellular fluid (ICF) from extracellular fluid (ECF) Outside cell Inside cell

11. The nucleus is the cell’s genetic control center Contains chromatin Genetic library with blueprints for nearly all cellular proteins Bound by a nuclear envelope with pores Contains a nucleolus

12. The endoplasmic reticulum is a biosynthetic factory Interconnected cisternae Continuous with nuclear membrane Two varieties: Rough ER Smooth ER

13. Lysosomes are digestive compartments within a cell Spherical membranous bags containing digestive enzymes (acid hydrolases)

14. Mitochondria harvest chemical energy from food Contains folds called cristae and its own DNA Provide most of cell’s ATP

15. Chloroplasts convert solar energy to chemical energy Chloroplasts: plant organelles ; site of photosynthesis Found in: All green parts of a plant; leaves are main site of photosynthesis Contain: green pigment chlorophyll involved in photosynthesis

16. Chloroplast Stroma Inner and outer membranes Granum Intermembrane space Chloroplasts convert solar energy to chemical energy

17. Plasma mem- brane Secretion by exocytosis Vesicle becomes lysosome Golgi apparatus Rough ER ER membrane Phagosome Extracellular fluid Secretory vesicle The Golgi apparatus finishes, sorts, and ships cell products Stacked and flattened membranous sacs (cisternae) Protein processing

18. The cell’s internal skeleton helps organize its structure and activities Elaborate series of rods throughout cytosol Microtubules (hollow) Microfilaments (solid) Intermediate filaments (solid)

19. Copyright © 2010 Pearson Education, Inc. Microfilament Actin subunit 7 nm Intermediate filament Fibrous subunits 10 nm Microtubule Tubulin subunit 25 nm Nucleus

20. Cilia and flagella move when microtubules bend Cilia and flagella Flagella - whiplike, tails that move entire cell Cilia -short, hairlike structures that move substances across cell surfaces

21. Membrane Junctions Three types: Tight junctions- Prevent fluids and most molecules from moving between cells Desmosomes- Rivets” or “spot-welds” that anchor cells together Gap junctions-Transmembrane proteins form pores that allow small molecules to pass from cell to cell For spread of ions between cardiac or smooth muscle cells

22. Tight junctions Anchoring junction Gap junctions Plasma membranes of adjacent cells Extracellular matrix