1. Chemistry of Life

2. All matter in the universe consists of elements  An element is a pure substance Examples of elements needed for life: CarbonC HydrogenH OxygenO NitrogenN PhosphorusP SulfurS

3. An atom is the smallest part of an element  Can only be seen with the most powerful microscope  Atoms join together to form molecules. Examples: Oxygen we breathe is a molecule made up of 2 oxygen atoms: O 2 Water is 2 hydrogens with 1 oxygen: H 2 O Sugar is a much bigger molecule: C 6 H 12 O 6 Sugar is a much bigger molecule: C 6 H 12 O 6 How many atoms in one sugar molecule?

4. How do atoms join? 1. Ionic bonds: atoms with opposite charges are attracted to each other Example: table salt: NaCl 2. Covalent bonds: strong bonds! Takes energy to break them apart Example: water, sugar

5. Important molecules for life ***Water*** We take it for granted, but water has many unique properties that support life. In fact, scientists who look for life on other plants focus on places where water does or used to exist

6. Properties of water   Polar molecule, hydrogen bonds   Universal solvent   High specific heat   Cohesion, adhesion   Less dense as a solid (so ice floats)   Neutral pH (not an acid or base)   Exists on Earth mostly as liquid

7. Important molecules for life Carbon-based molecules   Why carbon?

8. 1. 1. There’s lots of carbon in the universe It’s the second largest component of you, after water

9. 2. 2. It can make many different kinds of molecules Carbon can bond with one, two, three or four other atoms—and it can bond with other carbon atoms to form rings or long chains The bonds it forms are strong covalent bonds.

10. Molecules made with carbon that are found in living organisms are called organic compounds

11. Four types of organic compounds found in living things   Carbohydrates   Lipids   Proteins   Nucleic Acids These are called macromolecules Macro = giant (opposite of micro) http://www.authorstream.com/Presentation/PKYon ge-422910-pky-biology-macromolecules- macdonald-narrated-education-ppt-powerpoint/

12. Carbohydrates   Main purpose: ENERGY!

13. Carbohydrates   Provide the quick energy that powers all cell functions   Some energy storage (short term)   Structural building block --cellulose—plant cell wall --chitin—animal exoskeleton

14. All these carbohydrates are made of three elements: carbon, hydrogen, and oxygen.

15. Carbohydrates SugarsStarches

16. Sugars All carbs look like this in their simplest form. This is called a simple sugar or monosaccharide. mono = one saccharide = sugar Monosaccharides are building blocks for other sugars. If you put two of them together you get this. It’s called a disaccharide. Di = two

17. Sugars (and starches) are named with the ending -ose

18. If you string a bunch of monosaccharides together you get a polysaccharide. They look like this. Poly = many Starches Polysaccharides are starches.

19. Plant starch   Amylose – surplus glucose storage   Cellulose – structural support in the form of cell walls

20. Animal starch   Glycogen – one-day store of glucose in liver and muscles   Chitin – exoskeleton of some insects and cell wall of some fungi

21. Review   What are carbohydrates made of?   What is their major role in the cell?   What two major groups are carbohydrates divided into?   What are the building blocks of carbohydrates?   How is starch different from sugar?   How are carbohydrates named?

22. Lipids Main purposes: 1.Storage of energy. In case you run low on carbs 2. Thermal insulation. 3. Cushioning for delicate organs such as the heart. 4. Waterproofing. Like the wax in your ears.

23. Lipids   Fats and oils   Steroids   Phospholipids

24. Lipids   All lipids are formed from carbon, hydrogen, and oxygen.   Unlike other macromolecules, they are not polymers (made from many copies of one unit or mer)   All lipids are hydrophobic (literally afraid of water): they will not dissolve in water because they are nonpolar molecules.

25. Fats and oils Glycerol (an alcohol) + 3 fatty acids Fats are solids at room temperature while oils are liquids

26. Fats are efficient energy storage, insulation, and cushioning for organs

27. Steroids Cholesterol Precursor molecule   For Vitamin D   For hormones such as Testosterone and Estrogen

28. Phospholipids Phospholipids play a very important role in the structure of cell membranes.

29. Review   What are the different groups of lipids?   How are lipids similar to carbohydrates?   What property do all lipids share?   What important purposes do lipids serve?

30. Proteins Proteins are composed of 4 elements: carbon, hydrogen, oxygen and nitrogen. The basic unit is called an amino acid and it looks like this. This is a 3-D image of a protein containing thousands of amino acids connected together & folded to make this distinct shape.

31. Proteins All proteins are made from 20 amino acids. Each amino acid is different in one side chain: the “R” in the graphic A chain of amino acids is called a polypeptide because it is formed by joining amino acids with peptide bonds.

32. Proteins Their role in the body:   Important part of structures like skin and muscle   Antibodies – fight disease   Transport – like hemoglobin, the part of blood that carries oxygen to each cell   Regulate what enters and leaves cells – channels in cell membranes   Enzymes – catalyze reactions (lower the amount of energy needed for chemical reactions essential to cell function to take place)

33. http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__how_enzymes_work. html

34. Proteins make you who you are. The job of each gene of your DNA is to make a protein with a specific job within the cell.

35. Nucleic Acids DNA and RNA! Their job is to store all your hereditary information. More on them later!

36. Review   What elements are proteins made from?   What are the building blocks of protein?   What important purposes do proteins serve?   What are enzymes?   Why are proteins a uniquely important macromolecule?