Chemistry of Life (157 – 163) 6.3 Cell Processes Active and Passive Transport,

1. Chemistry of Life (157 – 163) 6.3 Cell Processes Active and Passive Transport, Osmosis, Diffusion, Exocytosis, and Endocytosis pp. 155 – 156; 195 -200 6.2, 8.1 Hickox: Baker High School Biology

2. Cell membranes are selectively permeable. This gives them the ability to maintain cell homeostasis by regulating what enters and leaves the cell. The direction of water movement across the cell membrane depends on the relative concentrations of free water molecules in the cytoplasm and in the fluid outside the cell. Different kinds of cells have evolved different ways of dealing with hypertonic, hypotonic, and isotonic solutions. The cells of plants have rigid cell walls that keep the cells from expanding too much. Animal cells can avoid swelling by moving dissolved particles from the cytoplasm. Most cell functions involve chemical reactions. Food molecules taken into cells react to provide the chemical constituents needed to synthesize other molecules. There are four main biochemicals: Carbohydrates, Proteins, Lipids and Nucleic acids. Cells use carbohydrates to provide energy. Cells use proteins for cellular construction and repair, cellular chemical activities, and as a back-up energy source if carbohydrates are not available. Both breakdown and synthesis are made possible by a large set of protein catalysts, called enzymes. Cells use lipids for cell membrane construction. Cells use nucleic acids to store genetic information for protein synthesis. • Objective 2.0: • Describe cell processes necessary for achieving homeostasis, including active and passive transport, osmosis, diffusion, exocytosis, and endocytosis • Identifying functions of carbohydrates, lipids, proteins, and nucleic acids in cellular activities • Comparing the reaction of plant and animal cells in isotonic, hypotonic, and hypertonic solutions • Explaining how surface area, cell size, temperature, light, and pH affect cellular activities • Applying the concept of fluid pressure to biological systems • Examples: blood pressure, turgor pressure, bends, strokes • Vocabulary • Carbohydrate • Nucleic Acid • Lipids • Proteins • Enzyme Core concept: Most cell functions involve chemical reactions. Food molecules taken into cells react to provide the chemical constituents needed to synthesize other molecules. There are four main biochemicals: Carbohydrates, Proteins, Lipids and Nucleic acids. Cells use carbohydrates to provide energy. Cells use proteins for cellular construction and repair, cellular chemical activities, and as a back-up energy source if carbohydrates are not available. Both breakdown and synthesis are made possible by a large set of protein catalysts, called enzymes. Cells use lipids for cell membrane construction. Cells use nucleic acids to store genetic information for protein synthesis. • Vocabulary • Passive transport • Active transport • Endocytosis • Isotonic • Exocytosis • Diffusion • Hypotonic • Hypertonic • Homeostasis • Osmosis Core concep: Cell membranes are selectively permeable. This gives them the ability to maintain cell homeostasis by regulating what enters and leaves the cell. The direction of water movement across the cell membrane depends on the relative concentrations of free water molecules in the cytoplasm and in the fluid outside the cell. Different kinds of cells have evolved different ways of dealing with hypertonic, hypotonic, and isotonic solutions. The cells of plants have rigid cell walls that keep the cells from expanding too much. Animal cells can avoid swelling by moving dissolved particles from the cytoplasm.

3. Core Concept: Small cells function more efficiently than large cells. Small cells can exchange substances more readily than large cells because small objects have a higher surface-area-to-volume ratio than larger objects. Most cells function best within a narrow range of light, temperature and pH. At very low temperatures, reaction rates are too slow. Extremes of light, temperature and pH can irreversibly change the structure of most protein molecules. Vocabulary: pH, surface area, volume Turgor pressure is the main pressure of the cell contents against the cell wall in plant cells and bacteria cells, determined by the water content. Blood pressure refers to the force exerted by circulating blood on the walls of blood vessels. High blood pressure can cause stroke. Breathing gas under pressure can present a myriad of possible medical problems. One of these is decompression sickness or "the bends," caused by breathing nitrogen or other gases under pressure, which are not metabolized by the body. • Vocabulary • Bends • Stroke Hickox: Baker High School Biology

4. Our journey begins here, atoms like Hydrogen (H) and Oxygen (O) Simple to Complex Life’s Levels of Organization Atoms come together to make up moleculeslike water, H2O. Molecules make up organelles. A group of organelles make up cells. Hickox: Baker High School Biology

5. CO2 + H2O C6 H12 O6 + 02 4. Chemical Reactions REACTANTS PRODUCT(S) Sun CHEMICAL EQUILIBRIUM

6. Acids and Bases 5. Acids are substances that forms in water and release hydrogen ions (H+). 6. Bases are substances that either take up hydrogen ions (H+) or release hydroxide ions (OH-). 7. pH measures how acidic or basic a solution is Hickox: Baker High School Biology

7. pH Scale 7. A pH scale is used to indicate how acid and basic of a solution. 8. Ranges from 0-14 • 7 = Neutral • >7 = Base • <7 = Acid Hickox: Baker High School Biology

8. Hickox: Baker High School Biology

9. pH Matters A strong acid is pH of 2 pH is a measure of proton (hydrogen ion or H+) concentration . Low pH = lots of H+s, high pH = few H+s. In biology, keeping H+ levels within a narrow range is critically important. A strong base is pH of 12

10. VIDEO FROM FILE Diffusion 9. Diffusionis the net movement of particles from an area of higherconcentration to an area of lowerconcentration. Diffusion continues until there is no concentration gradient! What affects the speed of Diffusion? 10. concentration: main factor, higher the more 11. temperature: if temp. increase greater diffusion 12. pressure: increasing pressure increases diffusion

11. Dynamic equilibrium no concentration gradient! Dynamic equilibrium

12. Osmosis Hickox: Baker High School

13. Osmosis 13. Isotonic Solution - Solute and Solvent (water) concentrations both inside and outside the membrane are equal. 14. Hypotonic Solution - Solution with a lower concentration of solute than the solution on the other side of the membrane. • Cells placed in a hypotonic solution will swell. • Lysis Hickox: Baker High School

14. Osmosis 15. Hypertonic Solution - Solution with a higher concentration of solute than the solution on the other side of the membrane. • Cells placed in a hypertonic solution will shrink. • Plasmolysis Hickox: Baker High School

15. Summary Section 2 – pages 152-156 The results of diffusion (write into notes) When a cell is in dynamic equilibrium with its environment, materials move into and out of the cell at equal rates. As a result, there is no net change in concentration inside or outside the cell. Material moving out of cell equals material moving into cell

16. 16. What type of osmosis is this?(Isotonic, hypotonic, or hypertonic)Does cell shrink, expand, or stay the same? isotonic Stays the same

17. 17. What type of osmosis is this?(Isotonic, hypotonic, or hypertonic)Does cell shrink, expand, or stay the same? hypotonic expands

18. 18. What type of osmosis is this?(Isotonic, hypotonic, or hypertonic)Does cell shrink, expand, or stay the same? hypertonic shrinks

19. Diffusion in Living Systems: the way cells move substances in and out of the cell Osmosis is the diffusion of particles through a semi- permeable membrane. Hypotonic Isotonic Hypertonic

20. Review Quiz: OSMOSIS VIDEO FROM FILE 20. ___________is the diffusion of particles through a semi- permeable membrane. 21. __________________:movement of particles across cell membranes by diffusion or osmosis. The cell uses NO energy to move these particles 22. ________________:the transport of materials against the gradient and this takes energy 23, _________________:the pushing out of water in a plant cell against the cell wall 24. __________________:shrinking of cell due to water moving out (dissolved solution outside cell high) 25._____________:swelling of a cell due to water moving in 26. ____________:concentrations inside and outside cell is balanced. Osmosis Passive transport Active transport Turgor pressure hypertonic hypotonic Isotonic

21. amino acids Three views of glucose, a common simple sugar. lipids Biomolecule: Structures vary RINGS BUNCHED CHAINS LONG CHAINS

22. Use these four major classes of biological molecules: Carbohydrate, lipid, protein, nucleic acid. Molecules of Life How do you build a cell? Start with water, add lots of small carbon-containing molecules and …….

23. Three views of glucose, a common simple sugar. Carbohydrates Carbon, Hydrogen, and Oxygen 27. Carbohydrates are used forenergyand to create structures. 28. The building blocks for carbohydrates are simple sugars.

24. Fat Phospholipid 30. Lipids are large and are made mostly of carbon and hydrogen and small amounts of oxygen. Lipids are used by cells for energy storage, insulation, and protective coatings, such as in membranes.

25. Phospholipids Form Double-Layered Biological Membranes

26. Protein p. 66 32. Proteins are the key elements of life. 33. Proteins provide structure for tissue and organs and carry out cell metabolism. Provide the body with the ability to move muscles. They are needed to transport oxygen in the bloodstream. 34. Enzymes, a type of protein that change the speed of chemicals reactions in the body.

27. Section 3 Check 34a. An enzyme (p. 66) is a protein that enables other molecules to undergo chemical changes to form new products. Enzymes increase the speed of reactions that would otherwise proceed too slowly. Substrate Active site

28. Strands of the Protein Keratin Create Hair

29. Nucleotides are Chains of Linked Amino Acids DNA and RNA 35. The building blocks of proteins are amino acids! 36. There are two kinds of nucleic acids, DNA and RNA. Both are involved in the storage and flow of information from gene to gene product.

30. 39. Nucleotides Are the Monomers That Create Polymers of DNA and RNA The small subunits that make up nucleic acids are nucleotides.

31. DNA Hickox: Baker High School Biology

32. RNA Mader: Biology 8th Ed.