Biology – The Building Blocks of Life Objectives: Objectives: –Describe normal cell growth and its limits –Define the causes and effects of cancer

Limits for Cell Growth –A cell has one set of DNA TRUE TRUE –One set of DNA can regulate a cell that is any size FALSE – one set of blueprints is NOT enough to build the biggest building FALSE – one set of blueprints is NOT enough to build the biggest building

Limits for Cell Growth –All nutrients & waste pass through the cell membrane TRUE TRUE –When a cell’s inside volume double, so too does the outside surface area FALSE FALSE The internal volume of a cell grows faster than the outside boundary (membrane) The internal volume of a cell grows faster than the outside boundary (membrane)

Surface to Volume Ratio S/V Ratio S/V Ratio Volume 4/3  r 3 Volume 4/3  r Surface 4  r 2 Surface 4  r Radius Radius Grow Break apart

Limits for Cell Growth (continued) –A larger cell has a hard time getting nutrient in and waste out of the cell TRUE TRUE –A cell undergoes division to solve its size problems TRUE TRUE

Controls of Cell Growth Muscle and Nerve cells do not divide…EVER! Muscle and Nerve cells do not divide…EVER! –TRUE Cells stop dividing when they touch another cell Cells stop dividing when they touch another cell –TRUE

Controls of Cell Growth Mitochondria dictate when a cell will divide Mitochondria dictate when a cell will divide –FALSE – the nucleus (DNA, chromosomes) dictates when a cell will divide Cell division can speed up & slow down under certain conditions Cell division can speed up & slow down under certain conditions –TRUE - (Injury, change in genetics, chemicals)

Cell Cycle Regulators The protein that controls cell division is called Dividein The protein that controls cell division is called Dividein –FALSE…the name of the protein is CYCLIN Injury can speed up the timing of the cell cycle. Injury can speed up the timing of the cell cycle. –TRUE

Uncontrolled Cell Growth Cancer = the cell’s inability to control its own growth Cancer = the cell’s inability to control its own growth –TRUE, by definition Tumors take up space & nutrients that normal cells need to survive Tumors take up space & nutrients that normal cells need to survive –TRUE It is normal for a cell to uncontrollably divide every now and then It is normal for a cell to uncontrollably divide every now and then –FALSE – that would be CANCER

Causes of Cancer Cancer MUST come from a change in genetics!!! Cancer MUST come from a change in genetics!!! –Radiation Sun’s UV rays, X-rays, nuclear Sun’s UV rays, X-rays, nuclear –Chemicals Nicotine, toxic waste, other chemicals Nicotine, toxic waste, other chemicals –Viruses ONLY IF it changes your DNA ONLY IF it changes your DNA –Genetic mutations (inherited) In the spot that regulates cell division In the spot that regulates cell division

Treatments for Cancer Radiation Radiation –“zap” the uncontrolled cells. You better kill them all. Miss one, it will start uncontrollablly dividing again! Surgery Surgery –Cut out the bad cells. You better get them all…or… Chemotherapy Chemotherapy –Use chemicals to slow down all cell division in your body. Leads to hair loss, stomach problems, weakness, etc.