Basic Biochemistry

1. Basic Biochemistry Water, Carbon, and Functional Groups

2. Water • Abundance of water makes Earth habitable • Unique properties

3. Water Molecules • Polar due to differences in electronegativity • Hydrogen bonds form

4. Properties of Water • Cohesion • Adhesion • Surface tension

5. Properties of Water • (What is temperature?) • High specific heat • Evaporative cooling • Good solvent

6. Interactions with Water • Hydrophilic vs. hydrophobic

7. Carbon • Can bond to 4 other atoms • Carbon chains can be long, be branched, or be circular • Hydrocarbon chains

8. Functional Groups • Most commonly involved in reactions • Types: • Hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, and phosphate • Chart pg. 64-65

9. ATP • Adenosine triphosphate used for energy transfer • ADP + Pi↔ ATP

10. Macromolecules

11. Review • What are the four essential macromolecules in the cell? • What are their structures? • What are their functions?

12. Macromolecules • Can be 10,000s of atoms • Polymers: linked chain of monomers • Variation in sequence is major difference

13. Dehydration Synthesis • Removal of water to link two monomers • Requires energy and help of enzymes • Hydrolysis breaks bonds (ex. Digestion)

14. Carbohydrates • Sugars and their polymers • Mono-, di-, and polysaccharides • Monosaccharides (-ose) can have three-seven carbons • Chain or ring forms

15. Carbohydrates • Glucose (C6H12O6) and Sucrose (C12H22O11) are most common • Polysaccharide uses: storage or structure

16. Carbohydrates • Starch = helical polymer of glucose (in plants) • Glycogen = more branched; stored in liver/muscle cells • Cellulose = most abundant organic compound • Never branched. Hydrogen bonding to nearby cellulose molecules. Microfibrils are structurally strong. • Chitin = fungi structures; exoskeletons

18. Lipids • Fats, steroids, phospholipids • Hydrophobic • Fats = glycerol (3-C alcohol) and 3 fatty acids (hydrocarbons) • Saturated vs. unsaturated • Primarily energy storage

19. Lipids • Phospholipids = glycerol + 2 fatty acids + phosphate • Partially hydrophilic, partially hydrophobic • Lipid bilayer membranes

20. Lipids • Steroids = four fused rings • Cholesterol, many hormones

21. Proteins • Most structurally complex • See chart pg. 78 for types • Enzymes catalyze reactions • 20 different amino acids combine to create a polypeptide

22. Proteins • Amino acids linked through peptide bonds in unique sequence • Proteins consist of multiple polypeptides • Function relies on proteins recognizing/bonding to other molecules

23. Protein Structure • PRIMARY: amino acid sequence • SECONDARY: α helix or β pleated sheet due to hydrogen bonding of C-N backbone

24. Protein Structure • TERTIARY: interactions between ‘R’ groups (ionic, hydrogen bonds, hydrophilic/phobic) • QUATERNARY: multiple polypeptide chains overlapping • Denaturing…

26. Nucleic Acids • DNA/RNA • Direct protein synthesis • Nucleotides  polynucleotides • Pyrimidines (T, U, G) vs. purines (C, A)

27. Nucleic Acids • Antiparallel double helix • 5’: phosphate • 3’: C-OH • Replication, transcription, translation

30. Phosphodiester Bond

31. Overview • Higher levels of organization result in new, more complex properties. • The structure of each macromolecule relates specifically to its function.

32. Self-Quiz, Chapter 5 Macromolecules

33. 1 • Which term includes all others in the list? • Monosaccharide • Disaccharide • Starch • Carbohydrate • Polysaccharide

34. 2 • Which of the following statements concerning unsaturated fats is true? • They are more common in animals than plants. • They have double bonds I the carbon chains of their fatty acids • They generally solidify at room temperature. • They contain more hydrogen than saturated fats having the same number of carbon atoms. • They have fewer fatty acid molecules per fat molecule.

35. 3 • The structural level of a protein least affected by a disruption in hydrogen bonding is the • Primary level. • Secondary level. • Tertiary level. • Quaternary level. • All structural levels are equally affected.

36. 4 • Which of the following pairs of base sequences could form a short stretch of a normal helix DNA? • 5’-purine-pyrimidine-purine-pyrimidine-3’ with 5’-purine-pyrimidine-purine-pyrimidine-5’ • 5’-A-G-C-T-3’ with 5’-T-C-G-A-3’ • 5’-G-C-G-C-3’ with 5’-T-A-T-A-3’ • 5’-A-T-G-C-3’ with 5’-G-C-A-T-3’ • 1, 2, and 4 are all correct.

37. 5 • Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? • The two strands of DNA would separate. • The phosphodiester bonds between deoxyribose sugars would be broken. • The purines would be separated from the deoxyribose sugars. • The pyrimidines would be separated from the deoxyribose sugar. • All bases would be separated from the deoxyribose sugars.

38. 6 • Which of the following is not a protein? • Hemoglobin • Cholesterol • An antibody • An enzyme • insulin

39. 7 • Which of the following statements about the 5’ end of a polynucleotide strand is correct? • The 5’ end had a hydroxyl group. • The 5’ end has a phosphate group. • The 5’ end is identical to the 3’ end. • The 5’ end is antiparallel to the 3’ end. • The 5’ end is in the fifth position on one of the nitrogenous bases.