1. Chemistry, Water and Enzymes

2. Daily Question Thursday, September 19 1. Calculate the number of atoms in Al 2 (SiO 3 ) 2 2.Describe how you figure out how many neutrons a particular atom has? 3. What makes water polar? 4. Describe why water molecules are attracted to each other. 5. What is the difference between cohesion and adhesion?

3. Organic Compounds

4. Carbohydrates Carbon, Hydrogen, and Oxygen Monosaccharides are building blocks –Glucose, fructose Polysaccharides: when many monosaccharides are linked together Can store energy for cells

5. Lipids Nonpolar Not soluble in water Fats, oils, steroids, and waxes Important to cell membrane Some store energy

6. Proteins Made of amino acids Promote chemical reactions, structural purposes, fight infections, support movements

7. Nucleic Acid Chain of nucleotides (sugar, base, and phosphate group) DNA, RNA

8. Chemistry

9. Structure of an Atom The nucleus of a helium atom contains 2 neutrons, shown in purple and 2 protons, shown in green. 2 electrons move around the nucleus at very extreme speeds.

10. Chemistry Basics Matter: anything that occupies space and has mass. Mass: how much matter something has. Atom: basic unit of matter. Nucleus: center, contains protons (+) and neutrons (0). electrons (-) move around the nucleus at tremendous speed.

11. Chemistry Basics Element: a substance made of only one kind of atom. Pure matter. Compound: atoms of two or more elements chemically combined.

12. Chemical Bonding

13. The arrangement of electrons determines how the atoms bond together. IMPORTANT: *all atoms (except H and He) have outer energy levels (shells) that can hold up to 8 electrons. *an atom becomes stable (happy!) when its outer energy shell has 8 electrons. *if outer shell is not full, the atom will react with other atoms that can provide electrons to fill its outer shell. *the outer shell reaches a stable state (happy!) by losing, gaining, or sharing electrons with other atoms.

14. Ionic Bonding Ionic Bonds: when atoms gain or lose electrons to form ions (charged particles).

15. Covalent Bonding Covalent Bond: when two or more atoms share electrons to form a molecule. In a water molecule, each hydrogen atom forms a covalent bond with the oxygen atom.

16. Properties of Water

17. Water and Polarity Each water molecule is held together by covalent bonds between 2 hydrogen atoms and 1 oxygen atom. The shared electrons are attracted more strongly by the oxygen nucleus than by the hydrogen. Therefore, water has positive and negative ends. Polar molecules: have unequal distribution of electrical charge. Hydrogen bond: weak chemical attraction between molecules.

18. Hydrogen Bonds in Water Hydrogen bonds form between water molecules.

19. Properties of Water 1.Polarity 2.Surface Tension (cohesion: attraction between molecules of the same substance) Creeps up thin tubes (adhesion: attraction between molecules of different substances)

20. Acids, Bases, and pH Water can break apart into 2 charged ions: H 2 OH + +OH - WaterHydrogen ionHydroxide ion Acid: a compound that forms H+ in solution. Base: a compound that forms OH- in solution. Solution: a mixture in which one or more substances are evenly distributed in another substance.

21. pH scale Base: 8 -14 Neutral: 7 Acid: 0 - 6

22. Chemistry

23. Structure of an Atom The nucleus of a helium atom contains 2 neutrons, shown in purple and 2 protons, shown in green. 2 electrons move around the nucleus at very extreme speeds.

24. Chemistry Basics Matter: anything that occupies space and has mass. Mass: how much matter something has. Atom: basic unit of matter. Nucleus: center, contains protons (+) and neutrons (0). electrons (-) move around the nucleus at tremendous speed.

25. Chemistry Basics Element: a substance made of only one kind of atom. Pure matter. Compound: atoms of two or more elements chemically combined.

26. Chemical Bonding

27. The arrangement of electrons determines how the atoms bond together. IMPORTANT: *all atoms (except H and He) have outer energy levels (shells) that can hold up to 8 electrons. *an atom becomes stable (happy!) when its outer energy shell has 8 electrons. *if outer shell is not full, the atom will react with other atoms that can provide electrons to fill its outer shell. *the outer shell reaches a stable state (happy!) by losing, gaining, or sharing electrons with other atoms.

28. Ionic Bonding Ionic Bonds: when atoms gain or lose electrons to form ions (charged particles).

29. Covalent Bonding Covalent Bond: when two or more atoms share electrons to form a molecule. In a water molecule, each hydrogen atom forms a covalent bond with the oxygen atom.

30. Properties of Water

31. Water and Polarity Each water molecule is held together by covalent bonds between 2 hydrogen atoms and 1 oxygen atom. The shared electrons are attracted more strongly by the oxygen nucleus than by the hydrogen. Therefore, water has positive and negative ends. Polar molecules: have unequal distribution of electrical charge. Hydrogen bond: weak chemical attraction between molecules.

32. Hydrogen Bonds in Water Hydrogen bonds form between water molecules.

33. Properties of Water 1.Polarity 2.Surface Tension (cohesion: attraction between molecules of the same substance) Creeps up thin tubes (adhesion: attraction between molecules of different substances)

34. Acids, Bases, and pH Water can break apart into 2 charged ions: H 2 OH + +OH - WaterHydrogen ionHydroxide ion Acid: a compound that forms H+ in solution. Base: a compound that forms OH- in solution. Solution: a mixture in which one or more substances are evenly distributed in another substance.

35. pH scale Base: 8 -14 Neutral: 7 Acid: 0 - 6