1. Biochemistry

2. Biochemistry
Study of the chemical composition and reactions of living matter

3. Organic VS Inorganic 2 major classes of chemicals in the body
Organic- Contain carbon
All compounds have covalent bonds
Inorganic- All others
Ex: water, salts, and many acids/bases

4. Inorganic Compounds Water Most abundant and important inorganic
60-80% of the volume of most living cells

5. Properties of Water High heat capacity/ heat storage capacity
Polar Solvent
Hydration layers
Transport
Reactivity
Cushioning
Organs
High heat of vaporization
Removal of heat through perspiration and evaporation

6. Salts
Ionic compound
Electrolytes: substances that conduct an electrical current in sol’n.
Nerve impulse transmission and muscle contraction
Ex: NaCl, CaCO3, KCl
Calcium phosphates: make bone/teeth hard

7. Homeostasis and Ions
Kidneys help to maintain proper ionic balance in body fluids

8. Acids and Bases
Acids: substance that releases H+ in detectable amounts (proton donors)
HCl  H+ + Cl –
Bases: Proton acceptors: release OH-
Ex: Bicarbonate: abundant in the blood
NaOH  Na+ + OH–

9. pH
Relative concentration of hydrogen ions in various body fluids

10. Acid-Base Concentration (pH)
Acidic: pH 0–6.99
Basic: pH 7.01–14
Neutral: pH 7.00
Figure 2.13

11. Neutralization Rxn
Acid + Base Salt + Water

12. Buffers Chemical systems that help regulate homeostatic pH balance
Release Hydrogen ions when pH increases and binds these ions when pH drops.

13. Weak VS Strong
Strong: Dissociated completely and irreversibly- can dramatically change pH
Hydrochloric Acid and Sulfuric Acid
Weak: Do not dissociate completely
bicarbonate

14. Carbonic Acid-Bicarbonate System
Carbonic acid dissociates, reversibly releasing bicarbonate ions and protons
The chemical equilibrium between carbonic acid and bicarbonate resists pH changes in the blood

15. Organic Compounds Unique to living systems Contain carbon
Generally very large with functional groups
No Carbon dioxide, CO, etc

16. Carbohydrates Contain carbon, hydrogen, and oxygen
Their major function is to supply a source of cellular food

17. Monosaccharides

18. Disaccharides

19. Polysaccharides

20. Functions of Carbs Small amounts used for structural purposes
Ready, easily used cellular fuel
ATP synthesis
Converted to fat when ATP supplies are sufficient

21. Lipids
Contain C, H, and O, but the proportion of oxygen in lipids is less than in carbohydrates
Examples:
Neutral fats or triglycerides
Phospholipids
Steroids
Eicosanoids

22. Neutral Fats (Triglycerides)
Composed of three fatty acids bonded to a glycerol molecule
Figure 2.15a

23. Other Lipids
Phospholipids – modified triglycerides with two fatty acid groups and a phosphorus group
Figure 2.15b

24. Other Lipids
Steroids – flat molecules with four interlocking hydrocarbon rings
Eicosanoids – 20-carbon fatty acids found in cell membranes
Figure 2.15c

25. Representative Lipids Found in the Body
Neutral fats – found in subcutaneous tissue and around organs
Phospholipids – chief component of cell membranes
Steroids – cholesterol, bile salts, vitamin D, sex hormones, and adrenal cortical hormones

26. Representative Lipids Found in the Body
Fat-soluble vitamins – vitamins A, E, and K
Eicosanoids – prostaglandins, leukotrienes, and thromboxanes
Lipoproteins – transport fatty acids and cholesterol in the bloodstream

27. Amino Acids
Building blocks of protein, containing an amino group and a carboxyl group
Amino group NH2
Carboxyl groups COOH

28. Amino Acids
Figure 2.16a–c

29. Amino Acids
Figure 2.16d, e

30. Protein
Macromolecules composed of combinations of 20 types of amino acids bound together with peptide bonds
Figure 2.17

31. Protein
Macromolecules composed of combinations of 20 types of amino acids bound together with peptide bonds
Amino acid
Dehydration
synthesis
Hydrolysis
Dipeptide
Peptide bond + N H C R O
H2O OH
Figure 2.17

32. Structural Levels of Proteins
Primary – amino acid sequence
Secondary – alpha helices or beta pleated sheets
Tertiary – superimposed folding of secondary structures
Quaternary – polypeptide chains linked together in a specific manner

33. Structural Levels of Proteins
Figure 2.18a–c

34. Structural Levels of Proteins
Figure 2.18b,d,e

35. Fibrous and Globular Proteins
Fibrous proteins
Extended and strand-like proteins
Examples: keratin, elastin, collagen, and certain contractile fibers

36. Fibrous and Globular Proteins
Compact, spherical proteins with tertiary and quaternary structures
Examples: antibodies, hormones, and enzymes

37. Protein Denuaturation
Reversible unfolding of proteins due to drops in pH and/or increased temperature
Figure 2.19a

38. Protein Denaturation
Irreversibly denatured proteins cannot refold and are formed by extreme pH or temperature changes
Figure 2.19b

39. Molecular Chaperones (Chaperonins)
Help other proteins to achieve their functional three-dimensional shape
Maintain folding integrity
Assist in translocation of proteins across membranes
Promote the breakdown of damaged or denatured proteins

40. Characteristics of Enzymes
Most are globular proteins that act as biological catalysts
Holoenzymes consist of an apoenzyme (protein) and a cofactor (usually an ion)
Enzymes are chemically specific

41. Characteristics of Enzymes
Frequently named for the type of reaction they catalyze
Enzyme names usually end in -ase
Lower activation energy

42. + Active site Amino acids Enzyme (E) Enzyme-substrate complex (E-S)
Internal rearrangements
leading to catalysis
Dipeptide product (P)
Free enzyme (E)
Substrates (S)
Peptide bond
H2O +
Figure 2.21

43. Nucleic Acids
Composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus
Their structural unit, the nucleotide, is composed of N-containing base, a pentose sugar, and a phosphate group

44. Nucleic Acids
Five nitrogen bases contribute to nucleotide structure – adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U)
Two major classes – DNA and RNA

45. Deoxyribonucleic Acid (DNA)
Double-stranded helical molecule found in the nucleus of the cell
Replicates itself before the cell divides, ensuring genetic continuity
Provides instructions for protein synthesis

46. Structure of DNA
Figure 2.22a

47. Structure of DNA
Figure 2.22b

48. Ribonucleic Acid (RNA)
Single-stranded molecule found in both the nucleus and the cytoplasm of a cell
Uses the nitrogenous base uracil instead of thymine
Three varieties of RNA: messenger RNA, transfer RNA, and ribosomal RNA

49. Adenosine Triphosphate (ATP)
Source of immediately usable energy for the cell
Adenine-containing RNA nucleotide with three phosphate groups

51. Hooray for the end of Chapter 2!!!!