Chap002_PPT (1) Physiology

Page 1: Copyright Notice

• Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without prior written consent.

Page 2: Importance of Chemistry in Anatomy and Physiology

• Chemistry in Physiology:

  • Concerned with the composition of substances and their changes in chemical reactions.

  • Human body, food, and medications consist of chemicals.

  • All anatomical structures are rooted in chemistry; physiological processes are chemical reactions.

  • Water and electrolytes constitute all body fluids.

Page 3: Elements and Atoms

• Elements: Simplest matter types with distinct chemical properties (92 naturally occurring elements).

• Compounds: Chemical combinations of different elements.

• Atoms: Smallest units of an element.

• Different Element Requirements:

  • Bulk Elements: Needed in large amounts (e.g., C, O, H, N, S, P).

  • Trace Elements: Needed in small amounts (e.g., Fe, I).

  • Ultratrace Elements: Needed in very minute quantities (e.g., As).

Page 4: Elements in the Human Body

• Major Elements by Weight:

  • Oxygen (O): 65.0%

  • Carbon (C): 18.5%

  • Hydrogen (H): 9.5%

  • Nitrogen (N): 3.2%

  • Calcium (Ca): 1.5%

  • Phosphorus (P): 1.0%

• Trace Elements:

  • **Cobalt (Co), Copper (Cu), Fluorine (F), Iodine (I), Iron (Fe), Manganese (Mn), Zinc (Zn) - all < 0.1% weight.

Page 5: Molecules and Compounds

• Molecule: Formed when two or more atoms chemically combine.

• Compound: Formed when two or more atoms of different elements combine.

• Molecular Formulas: Show elements and their atom counts.

  • Example: H2 (hydrogen), C6H12O6 (glucose), H2O (water).

Page 6: Bonding of Atoms

• Chemical Bonds: Formed through interactions between electrons.

  • Electron shell capacities:

    • 1st shell: 2 electrons.

    • 2nd shell: 8 electrons.

    • 3rd shell: 8 electrons.

  • Outermost shell electrons are crucial for forming chemical bonds.

Page 7: Ionic Bonds

• Ions: Charged atoms from gaining or losing electrons.

• Cation: Positively charged ion (loses electrons).

• Anion: Negatively charged ion (gains electrons).

• Ionic Bonds: Formed when opposite charges attract.

Page 8: Ionic Bonds Diagram

• (Refer to Figure 2.4 for illustrations of ionic bonds.)

Page 9: Covalent Bonds

• Covalent Bonds: Formed by sharing electrons among atoms.

  • Example: H2 (hydrogen molecule), which combines and stabilizes.

  • Covalent bonding with oxygen forms H2O (water).

Page 10: Covalent Bonds Diagram

• (Refer to Figure 2.5b for illustrations of covalent bonds.)

Page 11: Nonpolar & Polar Covalent Bonds

• Nonpolar Covalent Bonds: Electrons shared equally (same electronegativity).

• Polar Covalent Bonds: Electrons shared unequally (different electronegativities).

  • Forms polar molecules with uneven charge distribution (e.g., water is polar).

Page 12: Hydrogen Bonds

• Hydrogen Bonds: Weak attractions between polar molecules.

  • Occur between adjacent water molecules.

  • Essential for structures of proteins and nucleic acids.

Page 13: Hydrogen Bonds Diagram

• (Refer to Figure 2.8b for illustrations of hydrogen bonds.)

Page 14: Chemical Reactions

• Chemical Reactions: Involves formation or breaking of chemical bonds.

  • Reactants: Starting materials for reactions.

  • Products: Substances formed at the reaction's conclusion.

Page 15: Types of Chemical Reactions

• Synthesis Reaction: Complex structures formed.

• Decomposition Reaction: Simplifying bonds.

• Exchange Reaction: Bonds broken and reformed.

• Reversible Reaction: Reactants can revert to products.

Page 16: Electrolytes, Acids & Bases, and Salts

• Electrolytes: Substances releasing ions in water, allowing current conduction.

• Acids: Release hydrogen ions in water.

• Bases: Release ions combining with hydrogen ions.

• Salts: Formed from reactions between acids and bases.

Page 17: pH: Acid and Base Concentrations

• pH Scale: Indicates acid/base concentrations, with values from 0 to 14.

  • <7 denotes acidic, >7 denotes basic; 7 is neutral.

  • Each unit difference is a tenfold concentration change.

Page 18: Abnormal pH Conditions

• Normal blood pH: 7.35 - 7.45.

• Acidemia: pH 7.0 - 7.3, leading to symptoms like disorientation and fatigue.

  • Causes: Alkaline loss, diabetes, impaired CO2 exhalation.

• Alkalemia: pH 7.5 - 7.8, causing dizziness and agitation.

  • Causes: High altitude, vomiting acidic contents, excess antacids.

  • Homeostasis: Buffers help regulate pH by binding and releasing ions.

Page 19: Chemical Constituents of Cells

• Organic vs. Inorganic Molecules:

  • Organic: Contain C and H; include carbohydrates, proteins, lipids, nucleic acids.

  • Inorganic: Typically lack C and H; include water, oxygen, carbon dioxide, salts.

Page 20: Organic Substances: Carbohydrates

• Function: Primary energy source for cells; structural builder.

• Composition: C, H, O; H:O ratio close to 2:1 (e.g., glucose C6H12O6).

• Classification:

  • Monosaccharides: Single sugars (glucose, fructose).

  • Disaccharides: Double sugars (sucrose, lactose).

  • Polysaccharides: Complex carbohydrates (starch, glycogen, cellulose).

Page 21: Organic Substances: Lipids 1

• Lipids: Insoluble in water, soluble in organic solvents.

  • Include triglycerides, phospholipids, steroids.

  • Major role in cell membrane structure; have various functions.

• Triglycerides: High energy storage molecules, made of glycerol and 3 fatty acids.

Page 22: Saturated & Unsaturated Fatty Acids

• Saturated Fatty Acids: Only single bonds; typically solid at room temperature; animal sources.

• Unsaturated Fatty Acids: At least one double bond; usually liquid at room temperature; plant sources.

Page 23: Lipids Diagram

• (Refer to Figure 2.13 for illustrations of organic substances: lipids.)

Page 24: Organic Substances: Lipids 2

• Phospholipids: Similar to triglycerides but with phosphate group; key in cell membranes.

• Steroids: Four carbon ring structure, function in various biological processes; cholesterol plays a major role.

Page 25: Lipids Diagram

• (Refer to Figure 2.15 for illustrations of triglycerides and phospholipids.)

Page 26: Organic Substances: Proteins

• Proteins: Essential for structure, energy, hormones, receptors, enzymes, antibodies.

• Composed of amino acids (with amino group, carboxyl group, and unique side chain).

• Peptide Bonds: Link amino acids; formed between amino and carboxyl groups of adjacent amino acids.

Page 27: Organic Substances: Nucleic Acids 1

• Nucleic Acids: Encode genetic information (DNA) and support protein synthesis (RNA).

• Nucleotides: Made of a sugar, phosphate group, and organic base.

• DNA: Double chain; RNA: single chain.

Page 28: Organic Substances: Nucleic Acids 2

• DNA: Stores genetic code; contains deoxyribose sugar; features double-helix structure.

• RNA: Facilitates protein synthesis; contains ribose sugar; features a single-stranded structure.