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

Interest Grabber Getting Through Materials move through cells by diffusion. Oxygen and food move into cells, while waste products move out of cells. How does the size of a cell affect how efficiently materials get to all parts of a cell? Work with a partner to complete this activity. 1. On a sheet of paper, make a drawing of a cell that has the following dimensions: 5 cm x 5 cm x 5 cm. Your partner should draw another cell about one half the size of your cell on a separate sheet of paper. 2. Compare your drawings. How much longer do you think it would take to get from the cell membrane to the center of the big cell than from the cell membrane to the center of the smaller cell? 3. What is the advantage of cells being small? Go to Section:

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.

1st 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

2nd problem: DNA overload

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.

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

1. Why is the cell cycle called a cycle? The cell cycle represents recurring events that take place in the period of time from the beginning of one cell division to the beginning of the next. In addition to cell division, the cell cycle includes periods when the cell is growing and actively producing materials it needs for the next division. 1. Why is the cell cycle called a cycle? 2. Why do you think that it is important for a cell to grow in size during its cell cycle? 3. What might happen to a cell if all events leading up to cell division took place as they should, but the cell did not divide? Go to Section:

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

Parts of Interphase G1 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) G2 Phase Shortest of the 3 phases of interphase Organelles and molecules for cell division are produced (centrioles) Check-up phase before mitosis

Concept Map Cell Cycle Go to Section: includes M phase (Mitosis) Interphase is divided into is divided into G1 phase S phase Prophase G2 phase Metaphase Telophase Anaphase Go to Section:

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

Chromatin condenses in chomosomes before mitosis begins Chromosomes

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

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

M Phase, Cell Division and Mitosis

Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Chromatin Centromere Nuclear envelope Centriole Chromosomes (paired chromatids) Interphase Prophase Spindle Cytokinesis Centriole Metaphase Telophase Individual chromosomes Anaphase Nuclear envelope reforming Go to Section:

Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Chromatin Centromere Nuclear envelope Centriole Chromosomes (paired chromatids) Interphase Prophase Spindle Cytokinesis Centriole Metaphase Telophase Individual chromosomes Anaphase Nuclear envelope reforming Go to Section:

Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Chromatin Centromere Nuclear envelope Centriole Chromosomes (paired chromatids) Interphase Prophase Spindle Cytokinesis Centriole Metaphase Telophase Individual chromosomes Anaphase Nuclear envelope reforming Go to Section:

Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Chromatin Centromere Nuclear envelope Centriole Chromosomes (paired chromatids) Interphase Prophase Spindle Cytokinesis Centriole Metaphase Telophase Individual chromosomes Anaphase Nuclear envelope reforming Go to Section:

Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Chromatin Centromere Nuclear envelope Centriole Chromosomes (paired chromatids) Interphase Prophase Spindle Cytokinesis Centriole Metaphase Telophase Individual chromosomes Anaphase Nuclear envelope reforming Go to Section:

Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Chromatin Centromere Nuclear envelope Centriole Chromosomes (paired chromatids) Interphase Prophase Spindle Cytokinesis Centriole Metaphase Telophase Individual chromosomes Anaphase Nuclear envelope reforming Go to Section:

Mitosis Prophase Metaphase Anaphase Telophase

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

In plant cells, a cell plate forms 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.

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 _______________.

10-3 cell cycle regulation Homework 10-3 guided reading workbook Quiz, Chapter 10, on Thursday!!!

Controls on Cell Division

How do cells know when to divide and when not to? Internal regulators – are proteins that respond to events inside the cell. Cyclins External regulators - Proteins that respond to events outside the cell are called external regulators.

Cyclins 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!!

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.

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.