1. 10-1 Cell Growth Complete Guided Reading Workbook 10-1 and 10-2

2. By the end of today you will be able to: Explain the problems that growth causes for cells. Describe how cell division solves the problems of cell growth. Name and describe the main events of the cell cycle.

3. Let’s do some math!!!! Calculate the surface area of each sphere. Calculate the volume of each sphere. Then, calculate the surface area to volume ratio. Round #’s up or down to make it easier. S.A. = 4 (pi) r 2 Radius 2cm S.A. = ________ V = __________ Ratio SA:V = ________ Radius 2cm S.A. = ___50cm 2 __ V = __33cm 3 ____ Ratio SA:V = 50:33_or 1.51:1

4. Radius 2cm S.A. = ___50cm 2 __ V = __33cm 3 ____ Ratio SA:V = 50:33_or 1.51:1 Radius 1cm S.A. = _____ V = ______ Ratio SA:V = ___ S.A. = 4 (pi) r 2 Radius 1cm S.A. = __13cm 2 ___ V = __4cm 3 ____ Ratio SA:V = _13:4 or 3.25:1__ Radius 3cm S.A. = _____ V = ______ Ratio SA:V = ___ Radius 3cm S.A. = __113cm 2 _ V = ___113cm 3 ___ Ratio SA:V = _113:113 or 1:1__ 1.As the spheres get larger what happens to the SA:V ratio?

5. 1 st problem: Cell size and material exchange The larger a cell grows the more trouble it has… moving enough nutrients in Moving all the waste materials out

6. 2 nd problem: DNA overload

7. Checkpoint!!!! What are two problems that cell growth causes for cells? The larger a cell becomes, the more demands the cell places on its _____ and the more trouble the cell has moving enough _________and _________ across the cell membrane. What is viable solution for cells solve these problems? Cell Division – A larger cell splits into two smaller daughter cells.

8. The Cell Cycle and Mitosis Chapter 10-2 Homework 10-2-3 in guided reading

9. The Cell Cycle - series of events that cells go through as they grow and divide The cell cycle is divided into two halfs Interphase - period of the cell cycle between cell divisions M phase – period of time when mitosis and cell division occurs

10. Parts of Interphase G 1 Phase Growing Synthesize new proteins and organelles Doing their jobs Longest phase of cell cycle S Phase Chromosomes(DNA) are replicated Key proteins associated with replication are made (centromeres) G 2 Phase Shortest of the 3 phases of interphase Organelles and molecules for cell division are produced (centrioles) Check-up phase before mitosis

11. Chromatin and Chromosomes Chromatin - A complex of DNA and proteins in the cell nucleus that condenses to form chromosomes during cell division. Chromosomes – Condensed Chromatin They are the same stuff, just in different forms

12. Chromatin condenses in chomosomes before mitosis begins Chromatin Chromosomes

13. Different organisms have different #’s of chromosomes Humans cells – 46 Fruit Fly cells – 8 Carrot cells – 18 King Crab cells - 208

14. Chromosomes Replication During the cell cycle (before cell division can take place) chromosomes are replicated to form an identical copy of itself. Two identical copies of a chromosome are called “sister” chromatids – (one of two identical “sister” parts of a duplicated chromosome) Centromere - area where the chromatids of a chromosome are attached

15. M Phase, Cell Division and Mitosis

16. Mitosis Prophase Metaphase Anaphase Telophase

22. Cytokinesis - Cytoplasmic division and other changes exclusive of nuclear division that are a part of mitosis or meiosis.

23. In plant cells, a cell plate forms. The cell plate is synthesized by the fusion of multiple membrane- bounded vesicles. Their fusion supplies new plasma membrane for each of the two daughter cells. Synthesis of a new cell wall between the daughter cells then occurs at the cell plate.cell wall

24. 10-3 cell cycle regulation Homework 10-3 guided reading workbook

25. Checkpoint 1. The break down of a cell’s entire life is the _______ ________. 2. The phase of the cell cycle when the cell is growing, replicating DNA and getting ready for mitosis is _____________. 3-6. What are the four phases of Mitosis? 7. The process of a cell actually splitting in two is called _______________.

26. Controls on Cell Division

27. How do cells know when to divide and when not to? Internal regulators – are proteins that respond to events inside the cell. Some proteins make sure cells do not enter mitosis until all of the chromosomes have been replicated. What stage of the cell cycle do you think these proteins work? G 2 phase Cyclins – (internal regulator) one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells

28. Cyclins Protein that periodically rises and falls in concentration in step with the eukaryotic cell cycle. Cyclins activate crucial protein kinases (called cyclin-dependent protein kinases, or CDK) and thereby help control the progression from one stage of the cell cycle to the next. Cascade of events!!

29. Cyclins

30. External Regulators External regulators - Proteins that respond to events outside the cell are called external regulators. External regulators direct cells to speed up or slow down the cell cycle. Growth factors are among the most important external regulators, which tell cells to speed up division. When is this important? Molecules found on the surfaces of neighboring cells often have an opposite effect, causing cells to slow down or stop their cell cycles.

31. Uncontrolled Cell Growth Cancer cell Various forms of cancer have many causes Smoking Radiation Viral infections The common thread in all cancers is that control over the cell cycle has broken down. Over 50% of cancer cells have a defect in the p53 gene.

32. Quiz on Thursday HO due wednesday

33. p53 antioncogene p53 is a tumor suppressor gene found mutated in about half of human cancers. It encodes a gene regulatory protein that is activated by damaged DNA and is involved in blocking further progression of the cell cycle.

34. Oncogenes SRC, proto-oncogene tyrosine-protein kinase