logging in or signing up The_Cell_Cycle_Size_and_Regulation[1] wdorsey Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 124 Category: Education License: All Rights Reserved Like it (0) Dislike it (0) Added: February 17, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript The Cell Cycle: Size and Regulation : The Cell Cycle: Size and Regulation BIOLOGY Why do cells divide? : Why do cells divide? 1. For reproduction (in one-celled organisms) 2. For growth and development 3. For replacement of worn out or damaged cells Cell Growth Limits : Cell Growth Limits The cells of an adult are the same size as the cells of a child, there are just more of them. Limiting factors: DNA “Overload” Materials Exchange Limiting Factors: DNA “Overload” : Limiting Factors: DNA “Overload” Cell functions are controlled by DNA in the nucleus The larger the cell the more strain on its one copy of DNA Too large a cell and the DNA could not keep up with its needs Limiting Factors: Materials Exchange : Limiting Factors: Materials Exchange Food and waste pass through the membrane How fast depends on surface area of the cell How fast its used depends on volume of the cell Too big a volume for the surface area makes it hard to get enough material or get rid of waste fast enough Ratio of Surface Area to Volume : Ratio of Surface Area to Volume Cell Cycle Regulation : Cell Cycle Regulation Cells will grow or divide until they come in contact with another cell then stop If a gap is created, they grow to fill the gap There are 2 types of regulators: Internal Regulators External Regulators Cell Cycle Regulation: Internal : Cell Cycle Regulation: Internal A group of proteins – cyclins – regulate cell growth and division Some pause division until all chromosomes are copied Some hold off stages until everything is lined up right Cell Cycle Regulation: External : Cell Cycle Regulation: External Growth factors help start healing or growth spurts Hormones and other proteins Molecules on the surface of other cells tell it to stop Keep cells from overcrowding or damaging each other Cell Growth Unregulated : Cell Growth Unregulated Cancer is a disorder that results from the mutation of genes regulating the cell. Cancer cells: Divide uncontrollably Form masses of tissue called tumors Growth can spread through the body Apoptosis : Apoptosis Body’s normal cancer control If a cell breaks down or begins to get out of control, apoptosis occurs Lysosome bursts in the cell digesting it from the inside White blood cells clean up You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
The_Cell_Cycle_Size_and_Regulation[1] wdorsey Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 124 Category: Education License: All Rights Reserved Like it (0) Dislike it (0) Added: February 17, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript The Cell Cycle: Size and Regulation : The Cell Cycle: Size and Regulation BIOLOGY Why do cells divide? : Why do cells divide? 1. For reproduction (in one-celled organisms) 2. For growth and development 3. For replacement of worn out or damaged cells Cell Growth Limits : Cell Growth Limits The cells of an adult are the same size as the cells of a child, there are just more of them. Limiting factors: DNA “Overload” Materials Exchange Limiting Factors: DNA “Overload” : Limiting Factors: DNA “Overload” Cell functions are controlled by DNA in the nucleus The larger the cell the more strain on its one copy of DNA Too large a cell and the DNA could not keep up with its needs Limiting Factors: Materials Exchange : Limiting Factors: Materials Exchange Food and waste pass through the membrane How fast depends on surface area of the cell How fast its used depends on volume of the cell Too big a volume for the surface area makes it hard to get enough material or get rid of waste fast enough Ratio of Surface Area to Volume : Ratio of Surface Area to Volume Cell Cycle Regulation : Cell Cycle Regulation Cells will grow or divide until they come in contact with another cell then stop If a gap is created, they grow to fill the gap There are 2 types of regulators: Internal Regulators External Regulators Cell Cycle Regulation: Internal : Cell Cycle Regulation: Internal A group of proteins – cyclins – regulate cell growth and division Some pause division until all chromosomes are copied Some hold off stages until everything is lined up right Cell Cycle Regulation: External : Cell Cycle Regulation: External Growth factors help start healing or growth spurts Hormones and other proteins Molecules on the surface of other cells tell it to stop Keep cells from overcrowding or damaging each other Cell Growth Unregulated : Cell Growth Unregulated Cancer is a disorder that results from the mutation of genes regulating the cell. Cancer cells: Divide uncontrollably Form masses of tissue called tumors Growth can spread through the body Apoptosis : Apoptosis Body’s normal cancer control If a cell breaks down or begins to get out of control, apoptosis occurs Lysosome bursts in the cell digesting it from the inside White blood cells clean up