Macromolecules

1. Macromolecules Ch 3.3-3.20

2. In- Macromolecules Today we will begin discussing the four classes of macromolecules: Carbohydrates, lipids, proteins and nucleic acids. Give two to three examples of each type of macromolecule.

3. Functional Groups • All the functional groups we have learned are polar • The functional groups attach themselves to carbon skeletons and exhibit their chemical properties. • They are usually the direct participants in chemical reactions.

4. Making large molecules • Monomer-fundamental molecular unit. • Polymers- macromolecules made by linking together several monomers • Each of the macromolecules we will discuss are constructed of monomers strung into polymers

6. Dehydration Synthesis • Molecules synthesized by the loss of a water molecule between monomers • Builds polymers

7. Hydrolysis • “breaking apart with water” • Breaks down or degrades a polymer

8. Four Classes of Macromolecules • Carbohydrates • Lipids • Proteins • Nucleic Acids

9. Carbohydrates • The word “carbohydrate” indicates that these compounds are made of carbon and water (hydrates). • Monosaccharide is the simplest carbohydrate (monomers) • (CH2O)n – general formula for monosaccharide

11. Monosaccharides • “-ose” indicates sugar (fructose, glucose, etc) • In solution, many monosaccharides form a ring shaped molecule. • The basic role of simple sugars are as fuel to do work, as raw material for carbon backbones, and as monomers from which disaccharides and polysaccharides are synthesized.

12. Cells link two monosaccharides to form a disaccharide

13. How sweet it is… • Humans are born preferring sweet tasting foods and consume, on average in the US, 125 pounds per person per year. • There seem to be important biological reasons for this predilection from the standpoint of both animals and plants. What might they be?

14. Polysaccharides • Using glucose as a monomer, different organisms build several polymers. • Starch, glycogen and cellulose are all polysaccharides

15. Polysaccharides

16. Polysaccharides How are each of the polysaccharides made? Dehydration Synthesis How are they broken down? Hydrolysis

17. Starch • Used for long term energy storage in plants. • Helical and may be branched (amylose) or un-branched (amylopectin) • Animals can hydrolyze the polymer to obtain glucose.

18. Starch Granules

19. Glycogen • Used for long term energy storage only in animals. • Can by hydrolyzed to obtain glucose • Several branches. Why?

21. Cellulose • Principal structural molecule in the cell walls of plants and algae. • Different bonds between monomers than starch or glycogen. Forms linear polymers that are cross linked with other chains • Animals cannot hydrolyze this polymer for energy, only certain bacteria, fungi and protozoan's. What about cows? • Also known as fiber

22. Cellulose

23. Out - Carbohydrates Construct a table that summarizes the information we have discussed about carbohydrates. Remember to include names of monomers, polymers, uses, types, where they are found, shape, etc

24. Out- Carbohydrate Table

25. In- Lipids Fats are lipids. What is the difference between saturated and unsaturated fat in physical appearance and molecular structure? Give examples of each type of fat.

26. Lipids • Fats Oils, waxes, steroids • Serve primarily as energy storage • Predominantly carbon and hydrogen, fewer oxygen. • (CH2)n

27. Lipids - Structure

28. Lipids-Structure • Polymers of glycerol and fatty acid chains • Formed by dehydration synthesis reactions

29. Lipids are hydrophobic

30. Unsaturated *double bonds in fatty acid chains *liquid at room temperature *flexible, do not pack into globules *plant fats Saturated *single bonds between C *solid at room temp *pack together into large globules *animal fats Unsaturated vs. Saturated Fats

31. Saturated and Unsaturated Fats

33. Other types of Lipids • Phospholipids-major component of cell membrane. Glycerol head, two fatty acid “tails” • Waxes – hydrophobic coatings formed by organisms to ward off water. Fatty acid linked to an alcohol. • Steroids- an example of which is cholesterol, responsible for the breakdown of fats and the production of sex hormones.

34. Cholesterol, a Steroid

35. Out Lipid model construction

36. Thru-10/16/07 Proteins and Nucleic Acids

37. Proteins • Proteins are essential to the structures and activities of life • Structure, defense, contractile, storage, transport, signaling, catalyst. • Structure of the protein determines function • Constructed from amino acids

38. Proteins-Amino Acids • Only 20 kinds of AA make all of the proteins in living things • Central carbon atom covalently bonded to one hydrogen, one amino group, one carboxyl group, and one other chemical group (R) • The R group gives the AA its properties

40. Amino Acids • Linked by peptide bonds (dehydration synthesis) that form a chain called polypeptide • Chain is then folded into a specific shape • The shape of the chain determines the function of the protein

41. hydrolysis

43. Primary Primary Secondary Tertiary Quaternary

44. Protein Structure • Primary -amino acid sequence -changes in primary structure affect overall structure

45. Protein Structure • Secondary • Polypeptide coiling or folding • Produced by hydrogen bonding between –NH and –C=O groups of AA along chain • Alpha helix or pleated sheet

46. Protein Structure • Tertiary -Overall shape of the polypeptide -results from the clustering of hyrophobic/hydrophilic R groups as well as ionic and hydrogen bonding between R groups.

47. Protein Structure • Quaternary • Relationship btwn multiple polypeptides of a protein • Many (but not all) proteins consist of more than one primary chain. - Mostly hydrogen bonds

48. Nucleic Acids • Information-rich polymers of nucleotides • Store genetic information • DNA nucleotide sequences (genes) code for the production of proteins

49. Nucleotides • Three functional parts: phosphate group, 5 carbon sugar, nitrogenous base • 5 types: Adenine, Guanine, Cytosine, Thymine in DNA. Uracil in RNA instead of Thymine.