Specialized Cells PDF

# Teacher Notes: Specialized Cells Specialized means: has a specific _function_ in the body. Another word for specialized is _differentiated_. *Only multicellular eukaryotic organisms have specialized cells.* Before cells are specialized, they are called _stem cells_. *All the DNA in each of yo...

# Teacher Notes: Specialized Cells Specialized means: has a specific _function_ in the body. Another word for specialized is _differentiated_. *Only multicellular eukaryotic organisms have specialized cells.* Before cells are specialized, they are called _stem cells_. *All the DNA in each of your cells is the same. Your DNA = Your genome.* ## How cells become specialized 1. Stem cell receives _signal_ (called _hormones_). 2. DNA of cell uses directions in signals to turn on or off specific _genes_. 3. Based on activated genes, cell grows specific _structures_. 4. Cell is able to do its specific _function_ (job). *Can never go back to being a stem cell.* ## Some examples of Specialized Cells: ### Neuron Cell **Function:** Sends messages around the body. **Structures:** * Dendrites - connect to other nerves "tree-like". * Axon - insulated for super fast message transmission. ### Red Blood Cell **Function:** Deliver oxygen around the body. **Structure:** Very small, flexible, loses nucleus to increase surface area to carry oxygen. ### Sperm Cell **Function:** Swim to egg. **Structure:** * Flagellum = tail. * Mitochondria = lot of energy. ### Egg Cell **Function:** Grow and divide to form embryo. **Structure:** Extra large with protective outer layers. ### White Blood Cell **Function:** Fight disease. **Structure:** * Produce antibodies = recognize infections * Contain enzymes = break down invaders. ### Small Intestine Cell **Function:** Nutrient absorption. **Structure:** Microvilli = folds that increase surface area for absorption, finger-like. ### Pancreatic Cell (A, B, and D cells) **Function:** Synthesize, store and release hormones. **Structure:** Beta islet cells have lots of ribosomes to make insulin protein. (After a meal, the insulin hormone is received by a receptor protein on the cell surface to open transport protein to let in GLUCOSE) ### Bronchial Cells **Function:** Moisten, protects airways from pathogens to promote gas exchange. **Structure:** Ciliated cells that produce and sweep mucous which traps irritants and pathogens. ### Muscle Cells **Function:** Movement & support. **Structure:** Myofibrils (actin and myosin protein fibers) contract causing movement.