Biological molecules

1. Biological molecules Carbohydrates, Lipids, Proteins, and Nucleic Acids

2. Is it made of carbohydrates?

3. Carbohydrates

4. Carbohydrates • Organic compounds composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio. • A carbohydrate with 6 carbon atoms would have… ______ hydrogen atoms and ______ oxygen atoms 12 6 • Source of ENERGY • Structural components of cells

5. Monosaccharides • Monomer of carbohydrate (simple sugar) • Most have 6 carbon atoms • Most common: 1) Glucose (main source of energy) 2) Fructose (found in fruits) 3) Galactose (found in milk)

6. Isomers • Glucose, fructose, and galactose have the same chemical formula. C6H12O6 • Same formula but different structural forms.

7. Disaccharides and polysaccharides • Disaccharide: two monosaccharides bond to form a double sugar. • Example: sucrose • Polysaccharide: complex molecule composed of three or more monosaccharides.

8. Polysaccharides in animals and plants • Glycogen: animals store glucose in the form of the large, complex molecule – glycogen • Starch: plants store glucose molecules in the form of starch. • Cellulose: large polysaccharide made by plants, which provide strength and rigidity to plant cells.

9. White vs. whole grain

10. White vs. whole grain • White bread is a simple carbohydrate (little nutritional value, digested more quickly, converted to fat more quickly) • Whole grain bread is a complexcarbohydrate (high in fiber, vitamins and minerals, provide more energy, digested slowly)

11. Lipids

12. Lipids • Large organic molecules • Nonpolar – do NOT dissolve in water • Include phospholipids, triglycerides, waxes, steroids • Higher ratio of carbon and hydrogen to oxygen than carbohydrates…. More C-H bonds • Store more energy per gram than most other organic compounds

13. Fatty Acids • HydrocarbonEnd C-H Nonpolar Hydrophobic • Carboxyl End -COOH Polar Hydrophilic

14. Saturated: Each carbon atom is single-bonded to 4 other atoms; straight chain; molecules are close together; solid at room temperature Unsaturated: Double bonds in the C chain; kinked chain; molecules are farther apart; liquid at room temperature

15. Types of fatty acids: Saturated vs Unsaturated • http://www.youtube.com/watch?v=ESPNqKUluRs • Let’s list some more differences in the form and function of fatty acids

16. Types of Lipids made of fatty acids Triglycerides (FATS) • 3 fatty acids molecules joined to 1 glycerol • Saturated triglycerides are composed of saturated fatty acids (butter, other dairy products, fat from red meat) • Unsaturated triglycerides are composed of unsaturated fatty acids (mostly found oils and in plant seeds)

17. Types of Lipids made of fatty acids Phospholipids • Glycerol is connected to 2 fatty acid molecules and a phosphate group. • The plasma membrane of the animal and plant cells are composed of a phospholipidbilayer.

18. Types of Lipids made of fatty acids Waxes • Composed of a long fatty acid chain and a long alcohol chain. • Waterproof and provide protection. • Found on the surface of plants and in the ear canals of many animals (including humans).

19. Steroids • NOT composed of fatty acids • Four fused carbon rings which are attached to other functional groups • Cholesterol (found in the cell and plasma membrane) • Hormones such as testosterone and estrogen

20. Proteins

21. Is it made of Proteins?

22. Proteins ~ What are they? • Organic molecules compose of hydrogen, carbon, oxygen and NITROGEN • Monomers = AMINO ACIDS • Examples: • Hair • Horns • Skin • Muscles • ENZYMES (to learn more about later!)

23. Amino Acids (AA) • 20 different AA • Central carbon, C, that is covalently bonded to 4 other groups • Hydrogen = blue • Carboxyl (-COOH) = green • Amine (-NH2) = yellow • R group = red (varies in each AA and determines the AA’s form and function • AA can also be illustrated as a ball

24. DiPeptides and polypeptides • Dipeptide: two amino acids bond • Polypeptides: long chains of amino acids (made up of 1 or more dipeptide) • Making proteins: what builds them? • Reaction: condensation or hydrolysis • Water is released or used

25. DiPeptides and polypeptides • Some proteins are very large, some are small. • Protein shape: • Influences its function (form and function) • Shape can be influenced by factors like temperature and solvent) … for example, egg white is clear when it is uncooked, and white when it is cooked

26. ENZYMES • RNA or protein molecules that act as biological catalysts • Catalyst – speeds up the reaction by lowering the activation energy • Essential for cellular function • Each Enzyme bonds with a specificSubstrate for form the Active Site

27. How do enzymes work • Speed up reactions – how???? • Enzyme bonds to substrate and the enzyme shape changed slightly  • The chemical bonds in the substrate are weakened  • Lowers the activation energy • What happens after the reaction? • Enzyme releases the products • Enzyme is unchanged… • BUT changes in temperature and pH can change the enzyme (denature it) and it may not function properly or at all

28. Nucleic Acids

29. NUCLEIC ACIDS ~ source of the information • Large and complex biological molecules • Store and transfer important information in the cell • Genetic Code • Two types – both are polymers • 1. DNA - DeoxyriboNucleic Acid • 2. RNA - RiboNucleicAcid • DNA is transcribed into RNA, which is translated into PROTEINS

30. NUCLEIC ACIDS ~ structure • Each nucleotide is made of: • a phosphate group, • a five carbon sugar, and • a ring-shaped nitrogen base • Nitrogen bases • A - Adenine • C – Cytosine • G – Guanine • T – Thymine • U - uracil