Chapter 5 notes

1. Chapter 5 notes The structure and function of Macromolecules

2. Concept 5.1 ________: a long molecule consisting of similar or identical building blocks - like a train with many cars - ____________: repeating units that are the building blocks Diversity of life is based around 40 or 50 polymers

3. Concept 5.1 Monomers are connected together by ____________________ (anabolic) - covalent bond w/ the loss of H2O Polymers are broken down by ___________ (catabolic) - reverse rxn. of dehydration synthesis - “break with water”

4. Concept 5.1 1 2 3 H HO H HO Unlinked monomer Short polymer Dehydration removes a water molecule, forming a new bond H2O HO 1 2 3 4 H Longer polymer (a) Dehydration reaction in the synthesis of a polymer

5. HO H 4 1 2 3 Hydrolysis adds a water molecule, breaking a bond H2O HO H H HO 2 1 3 Concept 5.1

6. Concept 5.2 ____________: include sugars and polymers ________________ (monos = single; sacchar = sugar) - molecular formula is CH2O - ex. Glucose (C6H12O6) - most sugars are rings when aqueous

7. (a) Linear and ring forms (b) Abbreviated ring structure Concept 5.2

8. Concept 5.2 _____________: two monosaccharides joined by a glycosidic linkage - formed by dehydration synthesis - glucose + glucose = maltose + H2O - glucose + fructose = sucrose + H2O

9. Glucose Glucose Maltose (a) Dehydration reaction in the synthesis of maltose Glucose Fructose Sucrose (b) Dehydration reaction in the synthesis of sucrose Concept 5.2

10. Concept 5.2 ______________: polymers w/ few hundred to a few thousand monomers -fcn. of a polysaccharide is determined by monomers and positions of glycosidic linkages

11. Concept 5.2 Storage polysaccharides - _____: found in plants; consists only of glucose monomers (1-4 linkage); how plants store glucose (chloroplasts) - ___________: polymer of glucose found in animals; stored in liver and muscle cells

12. Concept 5.2 Structural polysaccharides - _________: major component of plant cell walls - note: 2 ring structures of glucose (alpha (a) and beta (b)) - cellulose is composed of all b glucose - cellulose = “insoluble fiber”

13. Concept 5.2  Glucose  Glucose (a)  and  glucose ring structures

14. Concept 5.2

15. Cell walls Cellulose microfibrils in a plant cell wall Microfibril 10 µm 0.5 µm Cellulose molecules • Glucose monomer Concept 5.2

16. Carbohydrates Structural polysaccharides (cntd.) - _________: carbohydrate used by arthropods to build exoskeletons - also used to make decomposable surgical thread

17. (a) (c) (b) Chitin forms the exoskeleton of arthropods. The structure of the chitin monomer. Chitin is used to make a strong and flexible surgical thread. Concept 5.2

18. Concept 5.3 ________: little or no affinity for water; consist mostly of hydrocarbons - 3 families: fats, phospholipids, steroids Fat: composed of 2 parts - _________: 3 carbon alcohol w/ hydroxyl - ___________: long carbon skeletons w/ carboxyl groups

19. Concept 5.3 Fatty acid (palmitic acid) Glycerol (a) Dehydration reaction in the synthesis of a fat

20. Concept 5.3 Fatty acids can vary in length and in the number and location of double bonds - “___________”: no double bonds; most animal fats; solid at room temp. - “_____________”: has one or more double bonds which removes H atoms; plants and fish; liquid at room temp.

21. Structural formula of a saturated fat molecule Stearic acid, a saturated fatty acid (a) Saturated fat Concept 5.3

22. Structural formula of an unsaturated fat molecule Oleic acid, an unsaturated fatty acid cis double bond causes bending (b) Unsaturated fat Concept 5.3

23. Concept 5.3 The major fcn. of fats is energy storage. - 1g of fat stores more than twice as much energy as 1g of a polysaccharide - mammals stock food reserves in adipose cells

24. Concept 5.3 ____________: similar to fats but have only 2 fatty acid tails; 3rd hydroxyl group joins to a phosphate group - show ambivalent behavior to water - head= _______ (hydrophilic); tail= ____________ (hydrophobic) - arranged in a bilayer, or double layer

25. Choline Phosphate Hydrophilic head Glycerol Fatty acids Hydrophobic tails Hydrophilic head Hydrophobic tails Space-filling model Phospholipid symbol (a) (b) (c) Structural formula Concept 5.3

26. Concept 5.3 ___________: lipids with a carbon skeleton consisting of 4 fused rings - differ in functional groups attached to rings - Cholesterol: found in animal cell membranes; precursor for other steroids

27. Concept 5.3

28. Concept 5.4 Proteins: account for more than 50% of the dry weight of most cells - used for structural support, storage, transport, signaling, movement, and defense

29. Concept 5.4 Proteins are polymers constructed from the same set of 20 _______________ - called ______________ - consist of one or more polypeptides folded and coiled into specific conformations

30. Concept 5.4 Amino acids are the building blocks of proteins - a carbon is bonded to an animo group, a carboxyl group, a hydrogen atom, and a variable (R) - grouped according to side chains (nonpolar, polar, acidic, basic)

31. Concept 5.4

32. Concept 5.4

33. Concept 5.4 Amino acids are bonded together by a _______________ - carboxyl group of one amino acid connects w/ the amino group of another (dehydration synthesis)

34. Concept 5.4

35. Concept 5.4 Four levels of protein structure - ______________: unique sequence of amino acids - even a slight change can affect a proteins conformation and ability to function - ex. Sickle-cell disease

36. Concept 5.4

37. Concept 5.4 - ______________: coils or folds that are a result of hydrogen bonds at regular intervals - _________: delicate coil held together by hydrogen bonding between every fourth amino acid - __________________: two or more regions lie parallel to each other

38. Concept 5.4

39. Concept 5.4 - _______________: irregular contortions from interactions between side chains (R groups) - hydrophobic interactions: nonpolar side chains cluster in the core, away from water - van der Waals interactions help hold them together

40. Concept 5.4 - disulfide bridges: covalent bond between two cysteine monomers (have sulfhydryl groups) - ionic bonds and hydrogen bonds also contribute

41. Concept 5.4

42. Concept 5.4 - ___________________: overall protein structure resulting from combining of multiple subunits The unique conformation endows each protein with a specific function

43. Concept 5.4

44. Concept 5.4

45. Concept 5.4 The unique conformation endows each protein with a specific function - _________________: protein unravels and losses its conformation - pH, [salt], temperature

46. Concept 5.5 Compounds that are responsible for determining the amino acid sequence of a polypeptide. Two types of nucleic acids - deoxyribonucleic acid (______) - ribonucleic acid (______) Flow of genetic information: DNA  RNA  Protein

47. DNA 1 Synthesis of mRNA in the nucleus mRNA NUCLEUS CYTOPLASM mRNA 2 Movement of mRNA into cytoplasm via nuclear pore Ribosome 3 Synthesis of protein Amino acids Polypeptide Concept 5.5

48. Concept 5.5 ______________ are the monomers (building blocks) of nucleic acids -nucleotide = nitrogenous base + pentose (5-carbon sugar) + phosphate

49. 5 end Nitrogenous bases Pyrimidines 5C 3C Nucleoside Nitrogenous base Thymine (T, in DNA) Uracil (U, in RNA) Cytosine (C) Purines Phosphate group Sugar (pentose) 5C Adenine (A) Guanine (G) (b) Nucleotide 3C Sugars 3 end (a) Polynucleotide, or nucleic acid Ribose (in RNA) Deoxyribose (in DNA) (c) Nucleoside components: sugars Concept 5.5

50. Concept 5.5 Two families of nitrogenous bases: - _______________: single ring; cytosine (C), thymine (T), and Uracil (U) - ____________: double ring; adenine (A), and guanine (G)