10-1 C ELL G ROWTH & D IVISION

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. Study for Test on Tuesday. Chapter 9 Respiration Do Now!! Look over quiz and practice test. Objectives Homework

L ET ’ 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

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?

1 ST PROBLEM : C ELL SIZE AND MATERIAL EXCHANGE The larger a cell grows the more trouble it has… moving enough nutrients in Moving all the waste materials out

2 ND PROBLEM : DNA OVERLOAD

C HECKPOINT !!!! 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.

C ELL G ROWTH AND D IVISION What problems does growth cause for cells? What are the “Main” events of the cell cycle? Hero articles due today. Loose-leaf paper –SA 10-1 and SA 10-2Due Monday 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. Key Concepts Homework

C ELL G ROWTH AND D IVISION What is the key difference between Cell Division and Mitosis? What are the stages of Mitosis? 1. What are the two main stages of the cell cycle? 2. Name and describe the stages of interphase. Key Concepts Do Now!

T HE C ELL C YCLE - 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

P ARTS OF I NTERPHASE 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

C HROMATIN AND C HROMOSOMES 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

C HROMATIN CONDENSES IN CHOMOSOMES BEFORE MITOSIS BEGINS Chromatin - a complex of DNA and proteins in the cell nucleus that condenses to form chromosomes during cell division. Chromosomes - Condensed Chromatin

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

C HROMOSOMES R EPLICATION 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

M P HASE, C ELL D IVISION AND M ITOSIS

10-2 P HASES OF M ITOSIS Name a describe the phases of Mitosis. P M A T Describe the process of cytokinesis. Handout Due Wednesday Quiz Tomorrow Cell Cycle & Mitosis Do Now!! What are the phases of Mitosis? P M A T Objectives Homework

M ITOSIS Prophase Metaphase Anaphase Telophase

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

Cytokinesis – division of the cell 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

B INARY F ISSION Prokaryotes circular DNA chromosome replication begins at one point in the circular chromosome copied regions begin to move to opposite ends of the cell

R EGULATING T HE C ELL C YCLE Internal Regulation Cyclins CDK’s (Cyclin Dependent Kinases) External Regulation Growth Factors Cytokines, HGH Triggers a signal-transduction pathway that leads to cell division Density-Dependent Inhibition Anchorage-Dependent Inhibition

The control cycle has a built-in clock, but it is also regulated by external adjustments and internal controls MPF – Maturation Promoting Factor (M- Phase Promoting Factor) G0G0

C YCLINS Family of Proteins that periodically rise and fall 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!!

DENSITY - DEPENDENT INHIBITION ANCHORAGE DEPENDENCE density-dependent inhibition anchorage dependence To divide they must be anchored to a substratum

C ANCER CELLS free of both density-dependent inhibition and anchorage dependence divide excessively and invade other tissues because they are free of the body’s control mechanisms

U NCONTROLLED C ELL G ROWTH Cancer cell Genetic Factors antioncogenes Oncogenes Environmental Factors 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.

P 53 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.

Oncogenes SRC, proto-oncogene tyrosine-protein kinase

P 53 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.

G ROWTH VS D EVELOPMENT How do cells regulate the cell cycle? Cancer Lab and Mitosis Packet due today!! Test on Friday Objectives Homework

C ELL G ROWTH VS D EVELOPMENT New daughter cells divide from existing cells to form identical cells Stem cells New daughter cells divide from existing cells, but changes occur to form new types of cells Blood Bones Skin Neurons Growth Development

C HECKPOINT 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 _____________ What are the four phases of Mitosis? 7. The process of a cell actually splitting in two is called _______________.