1. The Plant Cell Cycle Chapter 3

2. Nucleus DNA Replication Cytoskeleton

3. The plant cell NUCLEUS MITOCHONDRIUM CHLOROPLAST MITOCHONDRIUM CYTOSOL Notes: 1) cytosol is the same as cytoplasm 2) not all of the plant cell structures and organelles are shown Cell wall Plasma membrane

4. Fig. 3-8, p. 37 0.2 µm1 µm nuclear envelope one pore lipid bilayer facing the nucleoplasm nuclear envelope lipid bilayer facing the cytoplasm pore complex that spans both bilayers Nucleus -Ovoid or irregular shaped -Surrounded by double membrane (nuclear envelope)

5. Structure of Phospholipids and Glycolipids Hydrophilic Hydrophobic

6. Structure of Phospholipids and Glycolipids

7. Central dogma of Molecular Biology + DNA REPLICATION TRANSCRIPTION TRANSLATION RNA mRNA protein Ribosome

8. Early Prophase cell Chromosome Nucleolus (rDNA, rRNA, ribosomal proteins, etc…) nuclear envelope Nucleolus: production center for ribosomes

9. Structure of DNA

10. Fig. 3-9a, p. 37 A nucleosome consists of part of a DNA molecule looped twice around a core of histones (chromosomal proteins). core of histone molecules

11. Fig. 3-9b, p. 37 Immerse a chromosome in saltwater and it loosens up to a beads-on-a-string organization. The “string” is one DNA molecule. Each “bead” is a nucleosome.

12. Fig. 3-9c, p. 37 At a deeper level of structural organization, the chromosomal proteins and DNA are organized as a cylindrical fiber (again a helical structure).

13. Fig. 3-9d, p. 37 At times when a chromosome is most condensed (during Mitosis), the chromosomal proteins interact, which packages loops of already coiled DNA into a “supercoiled” array (two additional helical organizations). Such a tightly packaged DNA molecule is more easily moved around compared to when it would be a long “loose” thread (important during cell division)

14. Fig. 2-18, p. 26 oldnew old

15. Cytoskeleton Structures in cytoskeleton –Microtubules –Motor proteins –Microfilaments Specialized proteins connect microtubules and microfilaments to other organelles –Connections thought to coordinate many cell processes

16. Cell Cycle

17. Fig. 3-15, p. 43 some cells leave the cycle pre-DNA synthetic phase or gap phase DNA synthesis phase Interphase Mitosis (M) cytokinesis telophase anaphase metaphase prophase premitosis phase some cells leave the cycle CELL CYCLE G1G1 G2G2 S Note: Interphase includes G 1, S and G 2 phases

18. Fig. 3-16, p. 44 control point G2G2 G1G1 M S Principal Control Point Hypothesis

19. Fig. 3-18, p. 45 microtubules nucleus cell wall cytoplasm band of microtubules Formation of the preprophase band of microtubules in meristematic cells: A) Section at right angles to the plane of the future cell plate shows a cross section of microtubules. B) Section in the plane of the future cell plate shows microtubules encircling the nucleus. C) Three-dimensional drawing of A and B. ABC

20. Mitosis Four phases –Prophase –Metaphase –Anaphase –Telophase

21. Fig. 3-19, p. 46 Early Prophase Late Prophase Metaphase Late anaphase Telophase cell plate spindle fiber pole kinetochore chromosome nucleolus nuclear envelope Mitosis a b c d e

22. Fig. 3-17, p. 45 The roles of microtubules in mitosis Visualization of tubulin (component of microtubules) during mitosis.

23. Cell division in Plants versus Animals Animal cells do not have a cell wall Because plant cells have cell walls, the direction of cell division is a major determinant of overall plant development (cells are caught in a rigid structure and cannot reorganize after cell division has been completed). The direction/orientation of cell division is controlled by plant hormones.

24. Cell division in Plants versus Animals Animal cells do not form a preprophase band (PPB) During Telophase: - in plants: a cell plate is formed at the start of cytokinesis (direction of cell plate formation depends on hormone action via effects on PPB formation) - in animals: the cell pinches in the middle to form two cells, no cell plate is formed.