1. BIO 1140 – SLIDE 1 Topic 1 – Introduction to cell biology q Reading n Chapter 2 n Purple pages F-11 to F-34 n See BIO 1140 website q Objectives n Cell Theory n Basic properties of cells n Cell diversity: prokaryotic vs eukaryotic cells n Cell chemistry is water- and carbon-based n Macromolecules Karp 2008

2. BIO 1140 – SLIDE 2 What is a cell? q Fundamental unit of life n Every organism either consists of cells or is itself a single cell q Cell Theory I. All organisms consist of one or more cells II. The cell is the basic unit of structure for all organisms l Theodor Schwann,1839 (Matthias Schleiden, 1838) III. All cells arise only from pre-existing cells (i.e. the cell is the basic unit of reproduction) l Rudolf Virchow, 1855 Fig. 33.3 Fig. 21.2

3. BIO 1140 – SLIDE 3 q Can one speak of the cell? diversity n Enormous diversity in form, function and size unity n Similar basic chemistry (unity) l Similar chemical composition l Metabolism l Use of ATP as the cellular energy currency l Use of DNA for genetic information Fig. 33.3 Fig. 21.2

4. BIO 1140 – SLIDE 4 q Size matters! n Units relevant to cell biology l 1 µm = 10 -6 m l 1 nm = 10 -9 m l 1 Å = 10 -10 m = 0.1 nm n Cells are small l ‘typical’ prokaryote 1 – 5 µm l ‘typical’ eukaryote 10 – 30 µm n Why are cells small? Purple pages F2

5. BIO 1140 – SLIDE 5 n Why are cells small? l SA:V ratios l Rates of diffusion l Synthetic capacity Length = L Surface area = 6· L· L = 6L 2 Volume = L· L· L = L 3 SA:V = Length = 2L Surface area = 6· 2L· 2L = 24L 2 Volume = 2L· 2L· 2L = 8L 3 SA:V = time 0.067s 6.7 s 10.9 min 78 d X 0.1 mm 1 mm 1 cm 1 m Fig. 4-1 Becker et al. 2009 Time to 95% equilibration of O 2 by diffusion (see Fig. 2.27)

6. BIO 1140 – SLIDE 6 n Prokaryotic and eukaryotic cells differ in their solutions to the problem of size l Prokaryotes  For review, see http://salinella.bio.uottawa.ca/BIO1130/Lectures/PDF/BIO1130_lct03_StudentX6.pdf http://salinella.bio.uottawa.ca/BIO1130/Lectures/PDF/BIO1130_lct03_StudentX6.pdf  Solution  stay small, typically 1-5 µm  Simple structure: cell wall, plasma membrane, cytoplasm that lacks organelles (cyanobacteria possess photosynthetic membranes), ribosomes, nucleoid, flagellum Fig. 21.15 prokaryotes Bacterial flagellum Plasma membrane Cell wall Capsule Nucleoid Cytoplasm Ribosomes

7. BIO 1140 – SLIDE 7 n Prokaryotic and eukaryotic cells differ in their solutions to the problem of size l Prokaryotes  For review, see http://salinella.bio.uottawa.ca/BIO1130/Lectures/PDF/BIO1130_lct03_StudentX6.pdf http://salinella.bio.uottawa.ca/BIO1130/Lectures/PDF/BIO1130_lct03_StudentX6.pdf  Solution  stay small, typically 1-5 µm  Simple structure: cell wall, plasma membrane, cytoplasm that lacks organelles (cyanobacteria possess photosynthetic membranes), ribosomes, nucleoid, flagellum Fig. 21.15 prokaryotes Fig. 21.20 Fig. 21.11 Archaea (extremophiles) Bacteria Clostridium butyricum

8. BIO 1140 – SLIDE 8 n Prokaryotic and eukaryotic cells differ in their solutions to the problem of size l Eukaryotes  Protists (single-celled organisms), Fungi, Animals, Plants (multicellular)  Solution  compartmentalization of cellular functions Fig. 21.15 prokaryotes Nuclear envelope Nucleolus Nucleus Rough ER Smooth ER Free ribosomes Plasma membrane Golgi complex Mitochondrion Lysosome Cytosol Vesicle Fig. 2.18

9. BIO 1140 – SLIDE 9 n Prokaryotic and eukaryotic cells differ in their solutions to the problem of size l Eukaryotes  Protists (single-celled organisms), Fungi, Animals, Plants (multicellular)  Solution  compartmentalization of cellular functions Fig. 23.6 Fig. 23.18 Fig. 23.2 Fig. 23.4

10. BIO 1140 – SLIDE 10 n Prokaryotic and eukaryotic cells differ in their solutions to the problem of size l Eukaryotes  Protists (single-celled organisms), Fungi, Animals, Plants (multicellular)  Solution  compartmentalization of cellular functions http://www.cas.vanderbilt.edu/bioimages/ Purple pages F35-F39

11. BIO 1140 – SLIDE 11 Nuclear envelope Nucleolus Nucleus: Rough ER Smooth ER Free ribosomes Plasma membrane Golgi complex Mitochondrion Lysosome Cytosol Vesicle A gallery of eukaryotic cell organelles Fig. 2.18 q Major structural features n Plasma membrane n Nucleus (membrane-bound) n Membrane-bound organelles n Cytosol (vs cytoplasm)

12. BIO 1140 – SLIDE 12 q Non-membrane bound organelles n Cytoskeleton l Support/shape, internal organization, movement of cell, movement within cell l Microfilaments, microtubules, intermediate filaments n Ribosomes l Protein synthesis Fig. 2.22 MicrotubuleIntermediate filamentMicrofilament

13. BIO 1140 – SLIDE 13 q Membrane bound organelles n Nucleus l Nuclear envelope l Nuclear pores l Nucleolus l DNA and protein organized into chromosomes (chromatin) n Endoplasmic reticulum l Tubular membranes and cisternae l Rough – ribosomes, for membrane protein and secreted protein synthesis l Smooth – for lipid and steroid synthesis, detoxification Fig. 2.18

14. BIO 1140 – SLIDE 14 n Golgi complex l Stack of flattened vesicles l Sorting, modification and packaging of proteins n Vesicles l Transport among organelles and/or to plasma membrane n Lysosomes, peroxisomes l Contain hydrolases, catalases n Vacuole l Temporary storage l Turgor pressure in plant cells Fig. 2.20 Nucleus Rough ER Vesicles Golgi complex Lysosome

15. BIO 1140 – SLIDE 15 n Golgi complex l Stack of flattened vesicles l Sorting, modification and packaging of proteins n Vesicles l Transport among organelles and/or to plasma membrane n Lysosomes, peroxisomes l Contain hydrolases, catalases n Vacuole l Temporary storage l Turgor pressure in plant cells Fig4-6 Becker et al. 2009

16. BIO 1140 – SLIDE 16 n Mitochondrion l ~2 µm l Double membrane, cristae l Oxidative metabolism yielding ATP l Circular mDNA l Reproduce by fission n Chloroplast l ~5 µm l Double membrane + thylakoids l Conversion of light energy to chemical energy (complex carbohydrates) l Circular cpDNA l Reproduce by fission Fig. 6.8 Fig. 7.3 Figs. 1-18, 1-20, Alberts et al. 2004

17. BIO 1140 – SLIDE 17 n Endosymbiont theory l Mitochondria from incorporation of aerobic prokaryote l Chloroplast from (later) incorporation of cyanobacterium l Support – size, circular DNA, ribosomes, fission  Current examples: - symbiotic animals containing green photobionts - kleptoplasty (solar-powered sea slugs!) Fig. 2.21 Original prokaryotic cell Aerobic bacteria...... become mitochondria Photosynthetic bacteria...... become chloroplasts Eukaryotic cells (plants, some protists) Eukaryotic cells (animals, fungi, some protists)

18. BIO 1140 – SLIDE 18 n Endosymbiont theory l Mitochondria from incorporation of aerobic prokaryote l Chloroplast from (later) incorporation of cyanobacterium l Support – size, circular DNA, ribosomes, fission  Current examples: - symbiotic animals containing green photobionts - kleptoplasty (solar-powered sea slugs!) See: Rumpho et al. 2011 JEB 214, 303-311 http://sbe.umaine.edu/symbio/