Biology 20

1. Biology 20 Biochemistry

2. Explain how the human digestive and respiratory system exchange energy and matter with the environment • Describe the chemical nature of carbohydrates, lipids, and proteins and their enzymes.

3. Biochemistry • Atom - The smallest particle of an element • Element - A substance consisting entirely of one type of atom, for instance, carbon, hydrogen or oxygen. Elements can combine into compounds to form other substances. • Ion – an atom or group of atoms that have a charge • Compound - A substance consisting of more than one atom or one type of element, e.g. carbon dioxide is a compound.

4. Biochemistry • Covalent bond - Chemical bond formed by the sharing of one or more electron pairs between two atoms • Ionic bond - Chemical bonding resulting from the transfer of one or more electrons from one atom or a group of atoms to another.

5. Biochemistry • pH scale - scale is commonly used over a range 0 (acidic) to 14 (basic). • Acid - Substances that have a pH of lower than 7 (neutral) that can dissolve in water. • Base - Substances that have a pH of higher than 7 (neutral) that can dissolve in water. • Buffer - Solution that resists change in pH;

6. Metabolism • Metabolism: All the chemical reactions that occur within the cells. • Monomer: Basic subunit used to build larger molecules. Eg. Amino acids • Polymer: Molecules composed of many basic subunits bonded together • Eg. Many amino acids bond together to form on protein.

7. Polymer: Protein Monomer: Amino acid

8. Isomer - A chemical with the same number and types of atoms as another chemical, but possessing different properties. Chemistry Review

9. Catabolic Reactants • Complex chemicals broken down into smaller units • Eg. Breaking down food

10. Anabolic Reactions • Small units combine to make larger molecules • Eg. Plants and photosynthesis

12. Dehydration Synthesis • The process by which larger molecules are formed by the removal of water from two smaller molecules. + H20

13. Hydrolysis • The process by which a larger molecule is broken down into two smaller molecules. Water is taken up at the broken bond site. + H20

14. Chemistry Review • Organic Compounds • contain carbon atoms that are linked together • Inorganic Compounds • do not contain linked carbon atoms.

15. 4 Types • There are 4 major types of organic molecules important in biology. • Carbohydrates • monosaccharides, disaccharides, polysaccharides • Lipids • Triglycerides, Phospholipids, Waxes, Steroids • Proteins • Primary, Secondary, Tertiary, Quaternary • Nucleic Acids • DNA, RNA

16. Biochemistry Carbohydrates

17. Types of Carbohydrates Monosaccharides Disaccharides Polysaccharides

18. Carbohydrates • Characteristics • A Carbohydrate can be a single sugar or a polymer of many sugars. • Carbohydrates contain CHO • Carbon, Hydrogen, Oxygen • Ratio of carbon, hydrogen, oxygen = 1:2:1 • Purpose • Source of energy for cellular respiration • Structural material

19. Purposes of Carbohydrates Structural Major structural component of cell organelles, membranes and cytoplasm Energy Produced by photosynthesis, carbohydrates are the major energy source for cells. Energy is released through cell respiration

20. Monosaccharides

21. Types of Monosaccharides • Monosaccharides • Single sugar = C6H12O6 • Three common isomeres • Glucose • blood sugar • Fructose • fruit, honey, twice as sweet as glucose • Galactose • milk sugar, rarely found alone.

22. Types of Monosaccharides

23. Three Monosaccharides Galactose Glucose Fructose

24. Three Monosaccharides

25. Disaccharides

26. Disaccharides • Formed by the joining of 2 monosaccharides • Process called DEHYDRATION SYNTHESIS

27. Disaccharides

28. Dehydration Synthesis

29. Dehydration Synthesis

30. Disaccharides • Formed by the joining of 2 monosaccharides • Process called DEHYDRATION SYNTHESIS • The reverse process is called HYDROLYSIS

31. Disaccharides • Three Common Isomers • Sucrose • Glucose + Fructose • sugar cane, table sugar • Maltose • Glucose + Glucose • found in seeds of germinating plants • Lactose • Glucose + Galactose • Found in milk • Lactose Intolerance is common

32. Polysaccharides

33. Complex Carbohydrates

34. Important Polysaccharides Structural Storage Starch Glycogen Cellulose Chitin Exoskeletons...

35. Polysaccharides • Formed by the union of may monosaccharides by dehydration synthesis • Types: • Starch • Multiple sub-units of glucose • Storage form of energy in plants • Glycogen • Branched chains of glucose • Storage of of glucose in animals • liver and muscle cells • High Blood Glucose -- Glycogen formed in the liver • Low Blood Glucose -- Glycogen converted to glucose

36. Cellulose • Structural material found in plant cell walls • glucose is linked together differently compared to starch and therefore only organisms with cellulase can digest it. • Microbes in cow’s first stomach cleave the bonds with cellulase • The cow regurgitates (vomits into his own mouth) • chews again (gross!) • swallows into second stomach (yummy) • What is it good for?? • Roughage -- retains water in feces = soft poo

37. Biochemistry Lipids

38. Structure Contains CHO Ratio of H to O is greater than 2 to 1 Purpose Long Term Energy Storage 1 gram of lipids contains > twice the calories compared to carbohydrates or proteins Structural Material cell membranes cushion for organs carriers for vitamins raw material for synthesis of some hormones insulator Lipids

39. Classification of Lipids Phospholipid Steroid Triglyceride

40. Types of Lipids • Triglycerides • Formed from 1 glycerol and 3 fatty acids • formed by dehydration synthesis

41. Classification of Lipids Phospholipid Steroid Triglyceride

42. Triglyceride Formation

43. Triglyceride Formation

45. Types of Lipids • Triglycerides • Formed from 1 glycerol and 3 fatty acids • formed by dehydration synthesis 1) FAT • usually from animals • saturated fatty acids only contain single bonds • Very Stable -- hard to break down • solid or semi-solid at room temperature • Example: Butter

46. Types of Lipids 2) Oil • usually from plants • polyunsaturated fatty acids have some double bonds between carbon atoms • more reactive than fats therefore more easily broken down • liquid at room temperature • Example: Canola oil

48. Types of Lipids • Phospholipids • Have a phosphate molecule attached to a glycerol backbone

49. Classification of Lipids Phospholipid Steroid Triglyceride

50. Types of Lipids • Phospholipids • Have a phosphate molecule attached to a glycerol backbone • Polarized molecule • one side is relatively hydrophilic, other side hydrophobic • Major component of membranes • Waxes • Very stable • Insoluble in water • valuable waterproof coatings for plant leaves, animal feathers and fur