Biochemistry

1. Biochemistry the chemistry of living things

2. Macromolecules Biochemistry is the study of 4 groups of very large molecules/macromolecules… • Carbohydrates • Lipids • Proteins • Nucleotides

3. Macromolecules are composed of MONOMERS …repeating subunits • Each type of macromolecule is composed of different monomers. • Chains of monomers are called POLYMERS

4. MONOMERS POLYMERS

5. All polymers are assembled from their respective monomers by the same process… DEHYDRATION SYNTHESIS AKA CONDENSATION • A molecule of H2O is removed between the joined monomers.

7. Likewise, polymers are broken down into monomers by putting water back. • This process is called HYDROLYSIS

9. It doesn’t make any difference what macromolecule you are building or which you are breaking down. You will always use… DEHYDRATION SYNTHESIS and HYDROLYSIS

10. So monomers join to form polymers - macromolecules. Then these macromolecules come together to form the structures of living things such as ribosomes or membranes.

11. Now let’s look at each of the macromolecules…

12. Carbohydrates Source of energy & building material

13. Carbohydrates consist of C + H2O in a ratio of 1:1 example: 3C + 3 H2O = C3H6O3 • usually end in ose: example: glucose

14. 3 classes of carbohydrates • Monosaccharides • Disaccharides • Polysaccharides

15. Monosaccharides = Simple Sugars • Pentoses (5 C sugars) • Hexoses (6 C sugars)

16. Pentoses • Ribose used to make RNA • Deoxyribose (1 less O atom) used to make DNA

17. The 3 hexoses are isomers. • Hexoses are the monomers of carbohydrates.

18. Glucose (AKA Dextrose) is the most important of the HEXOSES Living things like to “burn” or oxidize glucose to get ENERGY

19. Disaccharides Disaccharides Are made by putting 2 monosaccharides together with the removal of water. The bond is called a glycosidic linkage

20. C6H12O6 + C6H12O6 C12H24O12 - H2O C12H22O11

22. Polysaccharides • can be used to store energy by chaining glucose monomers - plants store amylose (starch) - animals store glycogen • can be used to build structures - plants have cellulose - animals have chitin

24. Plants make sugar during photosynthesis. This sugar is then sent to a storage organ where it is converted to plant starch called amylose

25. Animals convert sugar they take in to glycogen. Glycogen is then stored in the liver and muscles so it is readily available for energy needs by breaking it down to sugars.

26. Cellulose is the structural polysaccharide of plants. It is used to make plant cell walls. It is the most abundant organic compound on earth! It is also known as fiber. We cannot breakdown fiber, so it speeds digestion, keeping us healthy!

27. Chitin is a structural polysaccharide used by animals. It forms the exoskeleton of insects and crabs.

28. Lipids Fats, waxes, oils, sterols, and steroids

29. Lipids differ from the other macromolecules in that they are… • nonpolar molecules • hydrophobic • classified on basis of solubility alone They have no general characteristics other than these.

30. Lipids include the following groups: • Triglycerides (AKA fats) • Phospholipids • Steroids

31. TRIGLYCERIDES (FATS) • 1 glycerol + 3 fatty acids

32. Glycerol is an alcohol. Can you identify Its functional group?

33. Fatty acids are organic acids. Can you identify their functional group? There are 2 types of fatty acids: Saturated – have all single bonds Unsaturated – have 1 or more double bonds

34. Saturated Fatty Acids • have all single bonds • are produced by animals • are solid at room temp

35. Unsaturated Fatty Acids • are produced by plants • contain 1 or more double bond • are liquid at room temperature

36. Fats are the best source of energy • They release twice the amount of energy as carbohydrates (gram for gram)

37. Triglycerides are assembled from glycerol and 3 fatty acids by dehydration synthesis. The bonds formed when water is removed are called ester linkages. Can you find the ester group?

38. Phospholipids Consist of… 1 glycerol + 2 fatty acids + P group The P “head” is charged and polar, while the fatty acid tails are nonpolar. This gives phospholipids some unique properties.

41. Because of the polar/hydrophilic P head and nonpolar/hydrophobic fatty acid tails they form a bilayer when placed in water. • Phospholipids are the main constituent of membranes.

42. Steroids • hydrophobic compounds • consist of 4 fused rings • vary with functional group attached to rings • all formed from cholesterol

44. Cholesterol • found in animals only • precursor to forming steroid hormones and vitamin D • UV rays convert cholesterol into vitamin D • Found in animal cell membranes where it keeps them fluid at low temperatures

45. Steroid Hormones • estrogens • progesterone • testosterone

46. Proteins - the building blocks of life

47. Functions of Proteins • Support silk, tendons, hair • Storage of amino acids for young egg white, milk • Transport hemoglobin • Hormones insulin, growth hormone • Receptors detect chemical signals • Movement muscle, cilia, flagella • Defense antibodies • Enzymes control chemical rxns

48. Genes are the recipes for proteins.

49. Amino acids are the monomers of proteins. Amino acids contain an amino and a carboxyl group. They differ only in their R group.

50. 5’ end 3’ end Amino acids are amphoteric – they become charged (+ at amino end and – at carboxyl end) .