XI. Concentration Gradients

1. XI. Concentration Gradients Higher Concentration 5% Sucrose 10% Sucrose A. The more solute dissolved in a solvent, the greater the solution’s concentration (strength).

2. XI. Concentration Gradients B. Differences b/t concentrations of solutes on both sides of a cell form concentration gradients to move substances in & out, past the cell membrane.

3. XI. Concentration Gradients All things in nature go from areas of high concentration to areas of low concentration unless acted upon by an opposing force All things in nature go from areas of high concentration to areas of low concentration unless acted upon by an opposing force All things in nature go from areas of high concentration to areas of low concentration unless acted upon by an opposing force All things in nature go from areas of high concentration to areas of low concentration unless acted upon by an opposing force All things in nature go from areas of high concentration to areas of low concentration unless acted upon by an opposing force All things in nature go from areas of high concentration to areas of low concentration unless acted upon by an opposing force All things in nature go from areas of high concentration to areas of low concentration unless acted upon by an opposing force

4. *High concentration of potassium [K ] outside the cell & low conc. inside the cell + + + + + + + + + + + + + + + + + + + + + + + + K K K K K K K K K K K K K K K K K K K K K K K + + + + + + + + + + + + + + + + + + + + Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na

5. + *Low concentration of sodium [Na ] outside the cell & high conc. inside the cell + + + + + + + + + + + + + + + + + + + + + + + K K K K K K K K K K K K K K K K K K K K K K K + + + + + + + + + + + + + + + + + + + + Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na

6. *Potassium moves into the cell and sodium move out of the cell + + + + + + + + + + + + + + + + + + + + + + K K K K K K K K K K K K K K K K K K K K K K + + + + + + + + + + + + + + + + + + + + Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na + K

7. *The sodium/potassium exchange across the membrane drives the process that makes energy for the cell. + + + + + + + + + + + + + + + + + + + + + + + K K K K K K K K K K K K K K K K K K K K K K K + + + + + + + + + + + + + + + + + + + + Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na

8. *As molecules move in, they bring with them the things the cell needs to carry out its functions. + + + + + + + + + + + + + + + + + + + + + + + K K K K K K K K K K K K K K K K K K K K K K K + + + + + + + + + + + + + + + + + + + + Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na

9. *As molecules move out, they carry waste & other cellular products out of the cell. + + + + + + + + + + + + + + + + + + + + + + + K K K K K K K K K K K K K K K K K K K K K K K + + + + + + + + + + + + + + + + + + + + Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na

10. XII. Water A. Most important compound for organic life

11. XII. Water + + H H O B. Is a polar molecule = it has a negative & positive end - forms hydrogen bonds

12. XII. Water + + H H O *Each hydrogen shares its electron with the oxygen [a covalent bond] filling everybody’s outer electron shell

13. XIII. Chemical Reactions A. When chemical reactions occur, bonds between atoms are formed or broken, & substances change into different substances

14. XV. Molecular Chains *form by bonding small molecules together into chains called polymers

15. XV. Molecular Chains A. Carbohydrates = used by cells to store and release energy. 1. Three Types;

16. a. Monosaccharide = simple sugar ex: fructose & glucose b. Disaccharide = two-sugar carbo. ex: sucrose [table sugar]

17. c. Polysaccharide = composed of many monosaccharide subunits ex: starch, cellulose & glycogen

18. XV. Molecular Chains Blubber B. Lipids [fats & oils] 1. Long-term energy storage, insulation & protective coatings [membranes]

19. XV. Molecular Chains *Main structural component of muscles C. Proteins = building blocks of the structural components of organisms