1. Carbon Compounds in Cells Chapter 3

2. Importance of Carbon Carbon permeates the world of life— from the energy-requiring activities and structural organization of cells, to physical and chemical conditions that span the globe and influence ecosystems everywhere.

3. Humans and Global Warming Fossil fuels are rich in carbon Use of fossil fuels releases CO 2 into atmosphere Increased CO 2 may contribute to global warming

4. Organic Compounds Hydrogen and other elements covalently bonded to carbon Carbohydrates Lipids Proteins Nucleic Acids

5. Carbon’s Bonding Behavior Outer shell of carbon has 4 electrons; can hold 8 Each carbon atom can form covalent bonds with up to 4 atoms

6. Methane: Simplest Organic Compound Structural formula Ball-and-stick model Space-filling model HH H H C Figure 3.2 Page 36

7. Bonding Arrangements Carbon atoms can form chains or rings Other atoms project from the carbon backbone Glucose (ball-and-stick model) In-text figure Page 36

8. Hemoglobin Molecular Models Ball-and-stick model Space-filling model Ribbon model Figure 3.3 Page 37

9. Functional Groups Atoms or clusters of atoms that are covalently bonded to carbon backbone Give organic compounds their different properties

10. Examples of Functional Groups Methyl group- CH 3 Hydroxyl group - OH Amino group- NH 3 + Carboxyl group- COOH Phosphate group- PO 3 - Sulfhydryl group- SH

11. Carbohydrates Monosaccharides (simple sugars) Oligosaccharides (short-chain carbohydrates) Polysaccharides (complex carbohydrates)

12. Most include fatty acids –Fats –Phospholipids –Waxes Sterols and their derivatives have no fatty acids Tend to be insoluble in water Lipids

13. Phospholipids Main component of cell membranes Hydrophobic head Hydrophilic tails Fig. 3.14a,b Page 43

14. Sterols and Derivatives No fatty acids Rigid backbone of four fused-together carbon rings Cholesterol - most common type in animals Figure 3.15a In-text p43 Cholesterol

15. Waxes Long-chain fatty acids linked to long-chain alcohols or carbon rings Firm consistency, repel water Important in water-proofing

16. Protein Synthesis Peptide bond –Condensation reaction links amino group of one amino acid with carboxyl group of next Water forms as a by-product Fig. 3.18a Page 45

17. Primary Structure Sequence of amino acids Unique for each protein Two linked amino acids = dipeptide Three or more = polypeptide Backbone of polypeptide has N atoms: -N-C-C-N-C-C-N-C-C-N-

18. Second and Third Levels Hydrogen bonding produces helix or sheet Domain formation Secondary structure Tertiary structure Figure 3.19a Page 46

19. Fourth Level Structure Some proteins are made up of more than one polypeptide chain HLA-A2 quaternary structure Figure 3.20 Page 47

20. Hemoglobin alpha chain beta chainalpha chain beta chain

21. Sugar At least one phosphate group Nitrogen- containing base Nucleotide Structure ATP Figure 3.23a Page 50

22. Nucleotide Functions Energy carriers Coenzymes Chemical messengers Building blocks for nucleic acids

23. DNA Double-stranded Sugar-phosphate backbone Covalent bonds in backbone H bonds between bases Figure 3.25 Page 51

24. RNA Usually single strands Four types of nucleotides Unlike DNA, contains the base uracil in place of thymine Three types are key players in protein synthesis