1. The Cell: the Basic Unit of Life Biotech Unit 2

2. All living things are composed of cells Made up of the same chemicals Made up of the same chemicals Use same basic design and building materials Use same basic design and building materials Carry out same processes in similar ways Carry out same processes in similar ways Use DNA to store and transmit information and for reproducing Use DNA to store and transmit information and for reproducing Use many different types of proteins to carry out their many processes Use many different types of proteins to carry out their many processes Introduction to Cells - YouTube Introduction to Cells - YouTube

3. Cells grow Increase in size and this requires building material and energy Increase in size and this requires building material and energy Break down large complex food molecules Break down large complex food molecules Proteins  amino acids ex. Enzymes, hemoglobin, insulin Proteins  amino acids ex. Enzymes, hemoglobin, insulin Proteins Peptide bonds Peptide bonds Lipids -  fatty acids and glycerol ex. Steroid, phosolipid layer Lipids -  fatty acids and glycerol ex. Steroid, phosolipid layer Lipids glycerol glycerol Carbohydrate  monosaccharideex. Glucose, starch, Carbohydrate  monosaccharideex. Glucose, starch, Carbohydrate polysaccharides cellulose, glycogen Nucleic Acid  nucleotidesex. DNA and RNA Nucleic Acid  nucleotidesex. DNA and RNA Nucleic Acid Nucleic Acid Deoxyribose, phosphate nitrogen base Deoxyribose, phosphate nitrogen base This process of breaking down large molecules for building blocks and then using these materials and energy into molecular manufacturing is known as metabolism This process of breaking down large molecules for building blocks and then using these materials and energy into molecular manufacturing is known as metabolism

4. Cells Reproduce Themselves Mitosis - all eukaryotic cells except gametes (sex cells) Mitosis - all eukaryotic cells except gametes (sex cells) Meiosis - eukaryotic cells that are gametes Meiosis - eukaryotic cells that are gametes Binary fission- prokaryotic cells Binary fission- prokaryotic cells

5. Cells Maintain Their Internal Environment- Homeostasis Cell’s internal environment is very different from their external environment. Cell’s internal environment is very different from their external environment. They control amounts of salts, chemicals and molecules They control amounts of salts, chemicals and molecules Cells must expend energy to maintain these differences Cells must expend energy to maintain these differences

6. Cells Respond to their External Environments When salt concentration change, they respond When salt concentration change, they respond In a harsh environment, a bacteria will move toward food and away from toxins In a harsh environment, a bacteria will move toward food and away from toxins A plant cell will react to an insect eating it by releasing a toxic chemical A plant cell will react to an insect eating it by releasing a toxic chemical Cells must sense the change  respond

7. Cells Communicate Cells Communicate EX- nerve cells give muscle cells the signal to contract EX- nerve cells give muscle cells the signal to contract A cell in tissue senses when it is touching another cell and stops growing- except in cancer cells A cell in tissue senses when it is touching another cell and stops growing- except in cancer cells Certain disease causing bacteria signal to each other to determine when their population is large enough to attach Certain disease causing bacteria signal to each other to determine when their population is large enough to attach A hormone produced in one organ affects certain cells A hormone produced in one organ affects certain cells

8. In Multi-celled Organism, Cell Specialize Cell differentiation- during development, a single fertilized egg divides and becomes specialized Cell differentiation- during development, a single fertilized egg divides and becomes specialized Cell differentiation- Cell differentiation-

9. Cells Require a Constant Supply of Energy Cells breaking down, building and rebuilding molecules and maintaining a stable internal environment all require energy. Cells breaking down, building and rebuilding molecules and maintaining a stable internal environment all require energy. Cells supply energy from breaking down macromolecules. Cells supply energy from breaking down macromolecules. Photosynthesis, chemosynthesis, and cellular respiration Photosynthesis, chemosynthesis, and cellular respiration

10. Cell Processes Involve chemical reactions- controlled by enzymes Involve chemical reactions- controlled by enzymes Occur in a series of small steps beginning with a starting material and ending up with an end product. This is called a pathway Occur in a series of small steps beginning with a starting material and ending up with an end product. This is called a pathway