1. Biological Chemistry

2. Macromolecules
Large organic molecules
Basic Structure
POLYMERIZATION!

3. Macromolecules
Carbohydrates
Lipids
Proteins
Nucleic Acids

4. Proteins

5. Proteins Chains of amino acids Basic structure below:
Basic amino acid structure shown above
Alpha-carbon 5

6. Proteins
Amino acid in solution
Structure shown: aldosterone 6

7. Proteins 20 amino acids Differ only in their side chains, R.
Structure shown: aldosterone 7

8. Condensation!

9. Proteins: Primary Structure
Order of amino acids
Protein made depends on
Kind: which amino acids are present?
Amount: how many amino acids?
Sequence: what’s the order they are arranged?
Amino acid sequence 9

10. Proteins: Secondary Structure
Folding & coiling form pleated sheets and helixes
Stabilized by hydrogen bonds
Sequence of amino acids are linked by hydrogen bonds 10

12. Proteins: Tertiary Structure
Long coils fold among themselves
Occurs when certain attractions are present between alpha helices and pleated sheets
Disulfide bonds
Hydrogen bonds 12

13. Proteins: Quaternary Structure
separate amino acid chains fit together to make the final structure of a protein
i.e., hemoglobin has 4!
Protein consisting of more than one amino acid chain 13

14. Overview
Conformation, or shape, of protein is basically the 2˚, 3˚, & 4˚ structure
Sequence controls 2˚, 3˚, & 4˚ structure. Therefore, primary structure controls conformation.

15. Proteins: What do they do?
Structural: collagen, elastin
Oxygen-carriers: hemoglobin, myoglobin
Forms parts of cell membranes: channels, receptors
Allow muscle contraction
Enzymes 15

16. Proteins: Enzymes
Protein catalysts that speed up important biological chemical reactions
All reactions require a certain activation energy (Ea) in order to happen.
In many reactions, few reactant molecules possess enough energy to react, so only those that do possess enough energy react. The result is a very slow reaction rate. HOWEVER, catalysts lower the activation energy that is required and makes the reaction much faster. 16

17. Proteins: Enzymes How do they work? substrates
Each enzyme (protein) has a very specific shape, due to primary  quaternary structure. The total confirmation (shape) of some enzymes is spherical or globular. Only a certain part of the enzyme molecule acts as the catalyst (active site). The reactants (now called substrates) are held by the enzyme so they can react easily. The only substrates held are those that fit the active site. 17

19. Proteins: Enzymes How does environment affect its activity?
Things to consider:
Temperature pH 19

20. Proteins: Enzymes How does environment affect its activity?
If the enzyme does not have exactly the right conformation (shape), it can’t hold the substrate and won’t work. If the conformation changes at any structural level, the protein breaks down and the enzyme becomes denatured (inactive). 20

21. Pepsin: works in stomach, where pH is very low, very acidic, so this environment is good -- digests other proteins
Trypsin: works in intestine at higher pH

22. Prosthetic group=bound covalently
Coenzyme= bound by hydrogen or ionic

23. allosteric site:  a site on a multi-subunit enzyme that is not the substrate binding site but that when reversibly bound by an effector (inhibitor) induces a conformational change in the enzyme, altering its catalytic properties.

24. Nucleic Acids

25. Nucleic Acids DNA: deoxyribonucleic acid RNA: ribonucleic acid
ATP: adenosine triphosphate 25

26. Nucleic Acids Monomers are called nucleotides
Each nucleotide has 3 parts
nitrogen-containing base
monosaccharide ribose
phosphate
Nitrogen-containing bases are either Adenine, Guanine, Thymine, & Cytosine.
C & T are categorized as pyrimidines (single ring)
G & A are categorized as purines (double ring)
FYI… nitrogenous base shown is adenine 26

27. Nucleic Acids Five kinds of bases Adenine Guanine
Thymine (in DNA only)
Cytosine
Uracil (in RNA only) 27

29. U Base-pairing rules; slightly different in DNA & RNA
since there is no thymine in RNA, adenine will form a bond with uracil
Notice that there is a pyrimidine matched with a purine!

30. Nucleic Acids Carbon-4 is missing the oxygen in deoxyribose.
(de-= without, oxy-= oxygen… DUH!) 30

32. DNA & RNA
form the genetic material of an organism

33. ATP
carries energy and provides to help many reactions in the cell