Chemistry Comes Alive

1. 2 P A R T A Chemistry Comes Alive

2. Human Blood Collection Bellringer – NOT to turn in • Blood is collected from your patient and treated so it will not clot. This blood is placed in a long narrow tube that is placed vertically on a laboratory bench. In an hour, all the blood cells have settled to the bottom of the tube, leaving the rest of the tube filled with a clear, yellowish liquid called plasma. Why did the blood cells settle out of the blood? • A. blood is an acidic solution of cells and plasma that sticks to the tube • B. blood is a mixture of solids and gases that react with the air • C. blood is a solution of Na+ and CL– ions that react to form a precipitate • D. blood is a suspension of cells in plasma that settles by gravity

3. Human Blood Collection Bellringer – NOT to turn in • Blood is collected from your patient and treated so it will not clot. This blood is placed in a long narrow tube that is placed vertically on a laboratory bench. In an hour, all the blood cells have settled to the bottom of the tube, leaving the rest of the tube filled with a clear, yellowish liquid called plasma. Why did the blood cells settle out of the blood? • A. blood is an acidic solution of cells and plasma that sticks to the tube • B. blood is a mixture of solids and gases that react with the air • C. blood is a solution of Na+ and CL– ions that react to form a precipitate • D. blood is a suspension of cells in plasma that settles by gravity

4. Matter • Anything that has mass and takes up space • States of matter • Solid – has definite shape and volume • Liquid – has definite volume, changeable shape • Gas – has changeable shape and volume • All are important in Anatomy & Physiology

5. Composition of Matter • Elements – unique substances that cannot be broken down by ordinary chemical means • Atoms –building blocks for each element

6. Major Elements of the Human Body • Oxygen (O) • Carbon (C) • Hydrogen (H) • Nitrogen (N)

7. Lesser and Trace Elements of the Human Body • Lesser elements make up 3.9% of the body and include: Calcium (Ca), phosphorus (P), potassium (K), sulfur (S), sodium (Na), chlorine (Cl), magnesium (Mg), iodine (I), and iron (Fe) • Trace elements make up less than 0.01% of the body

8. If given an element, identify if it is… • A major element of the body • A lesser element of the body • A trace element of the body • Vitamin Labels

9. Molecules and Compounds • Molecule – two or more atoms held together by chemical bonds • Compound – two or more different kinds of atoms chemically bonded together (water or H2O is an example)

10. Mixtures and Solutions • Mixtures – two or more components physically intermixed (not chemically bonded) • Example: blood cells in blood • Most mixtures can be separated by physical means • Solutions – homogeneous mixtures of components • Example: electrolytes such as Na+Cl-, K+CL-, etc. • Solvent – substance present in greatest amount • Solute – substance(s) present in smaller amounts

11. Types of Chemical Bonds • Ionic • Covalent • Hydrogen • Importance of polar and nonpolar molecules

12. Factors Influencing Rate of Chemical Reactions • Catalysts – increase the rate of a reaction without being chemically changed • Enzymes = biological catalysts

13. Biochemistry • Organic compounds • Contain carbon, are covalently bonded, and are often large • Inorganic compounds • Do not contain carbon • Water, salts, and many acids and bases

14. Salts (NaCL, KCL, Na2SO4, etc.) • Inorganic compounds • Contain cations other than H+ and anions other than OH– • Are electrolytes; they conduct electrical currents

15. Acids and Bases • Acids release H+ and are therefore proton donors HCl  H+ + Cl – • Bases release OH– and are proton acceptors NaOH  Na+ + OH–

16. Acid-Base Concentration (pH) • Acidic solutions have higher H+concentration and therefore a lower pH • Alkaline solutions have lower H+ concentration and therefore a higher pH • Neutral solutions have equal H+ and OH– concentrations

17. Acid-Base Concentration (pH) • Acidic: pH 0–6.99 • Basic: pH 7.01–14 • Neutral: pH 7.00 • Blood has pH ~ 7.4 • Most body fluids pH 7.2 – 7.6

18. Buffers • Chemical systems that resist abrupt and large swings in the pH of body fluids • Example: Carbonic acid-bicarbonate system in blood • Carbonic acid dissociates, reversibly releasing bicarbonate ions and protons • The chemical equilibrium between carbonic acid and bicarbonate resists pH changes in the blood

19. Bicarbonate Buffer System Removes Acid • If blood is too acidic: • HLac(aq) + HCO3-(aq) ↔ Lac-(aq) + H2CO3(aq) • Lactic Acid + Bicarbonate Lactate + Carbonic Acid • If blood is too basic (alkaline): • H2CO3(aq) ↔ H+(aq) + HCO3-(aq)Carbonic Acid Protons + Bicarbonate

20. Organic Compounds • Molecules unique to living systems contain carbon and hence are organic compounds • They include 4 important macromolecular biochemical polymers: • Carbohydrates • Lipids Be able to identify from • Proteins descriptions or pictures • Nucleic Acids }

21. Carbohydrates • Contain carbon, hydrogen, and oxygen • Their major function is to supply a source of cellular food • Examples: • Monosaccharides or simple sugars Figure 2.14a

22. Carbohydrates • Polysaccharides or polymers of simple sugars Figure 2.14c

23. 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

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

25. Other Lipids • Steroids – flat molecules with four interlocking hydrocarbon rings Figure 2.15c

26. 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 • Fat-soluble vitamins – vitamins A, E, and K

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. Examples of proteins

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

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

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

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

34. 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

35. 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

36. 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

37. Structure of DNA Figure 2.22b

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

39. Adenosine Triphosphate (ATP)