1. Molecules of Life Chapter 3

2. Molecules Inorganic compound Nonliving matter Salts, water Organic compound Molecules of life Contains Carbon (C) and Hydrogen (H) Carbon backbone

3. Carbon Chemistry Cell is mostly water The rest of the cell consists mostly of carbon-based molecules Carbon is a versatile atom four electrons in an outer shell that holds eight can share its electrons with other atoms to form up to four covalent bonds

5. Organic Molecules Many molecules of life are macromolecules (macromolecules contain many molecules joined together) Monomers :Simple organic molecules that exist individually Polymers :Large organic molecules form by combining monomers PolymerMonomer CarbohydrateMonosaccharide ProteinAmino acid LipidsTriglycerides Nucleic acidNucleotide

8. Molecules of Life 4 main classes of biological molecules 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids

9. Carbohydrates

10. Some Functions: Quick fuel Short-term energy storage Structure of organisms Cell to cell recognition Consist of C, H, and O atoms 1:2:1 ratio “ Saccharides” 3 major classes: Monosaccharides Disaccharides Polysaccharides

11. Monosaccharides “simple sugars”; “one monomer of a sugar” Dissolve easily in water hydrophilic Glucose C 6 H 12 O 6 Fructose Form of glucose

12. Disaccharides Short chain of two sugar monomers Two Monosaccharides Lactose, sucrose, maltose Lactose = glucose + galactose

13. Polysaccharide “Complex” carbohydrate Composed of many glucose molecules Glycogen Polysaccharide of glucose Storage form of glucose in animals Starch Storage form of glucose in plants Cellulose Found in the cell walls of plants

15. Lipids

16. Cells use lipids to store energy Hydrophobic Functions: Energy Storage Cushioning and Insulation Found in the plasma membrane 3 main types: Fats & Oils Phospholipids Steroids

17. Fats Dietary fat consists largely of the molecule triglyceride Combination of glycerol and three fatty acids

18. Fats Unsaturated fatty acids Have less than the maximum number of hydrogens bonded to the carbons Saturated fatty acids Have the maximum number of hydrogens bonded to the carbons Most animal fats have a high proportion of saturated fatty acids, which can be unhealthy Example: butter Most plant oils tend to be low in saturated fatty acids Example: corn oil

19. Phospholipids Glycerol, two fatty acids and a phosphate group Plasma membrane Nonpolar tail Polar heads

20. Proteins

21. Why Proteins?? VERY important functions in cells Keratin and collagen have structural roles Enzymes speed up chemical reactions of metabolism Responsible for transport of substances within the body Transport substances across cell membranes Hormones that regulate cellular function Insulin

22. Proteins Made from amino acids 20 various kinds Amino acids linked to one another by peptide bonds Two amino acids bound by a peptide bond is a dipeptide Three or more is a polypeptide chain

23. Protein Polypeptide Peptide / Dipeptide Amino Acids

24. Protein Structure Protein’s final shape and chemical behavior arise from it’s primary structure Chain bends, folds, coils, etc. Denaturing When proteins lose their shape

26. Nucleic Acids

27. Nucleotides and Nucleic Acids Nucleic acids Can be single stranded or double stranded DNA  Deoxyribonucleic acid  genetic information RNA  Ribonucleic acid  used to build proteins

28. Nucleotides and Nucleic Acids Nucleic acids Built by nucleotides Phosphate Pentose sugar Nitrogen-containing base

29. DNA Composition DNA is built from four different kinds of nucleotides One of four bases determines the nucleotide: A - Adenine G - Guanine T - Thymine C – Cytosine DNA consists of two strands of nucleotides twisted into a double helix

30. GAGA….a nucleotide repeat!! Base pairs Bases can only pair up with their corresponding “mate” 2 kinds: A – T G – C Amount of A = T Amount of G = C Can line up in any order

31. DNA Composition Nucleotides linked together by covalent bonds Bases of one strand linked to the other by hydrogen bonds The two strands run in opposite directions

32. DNA into RNA RNA a big player!! Single strand Sugar, phosphate group, and a N-containing base Bases are: A, C, G, and URACIL (U)