Chapter 2 :Chapter 2 Atoms, Ions, and Molecules


About this Chapter :About this Chapter Make up of atoms, ions, & molecules Bonds combine atoms, form molecules Concentrations Biomolecules


Atoms and Elements :Structure of an atom Protons Electrons Neutrons Mass Charge Nucleus Electron orbitals Elements Essential & trace elements Atoms and Elements Figure 2-1: Atomic structure


All the Elements :All the Elements Figure 2-2: Periodic table of the elements


Ions and Isotopes :Ions have charge Cations + Anions - Isotopes vary mass Neutrons Radioisotopes Unstable nuclei Emit energy -radiation Medical uses as tracers Ions and Isotopes


Ions and Isotopes :Ions and Isotopes Figure 2-3: A map showing the relationship between elements, ions, isotopes, and atoms


Molecules and Compounds :Common in biosystems Carbon (C) Oxygen (O) Hydrogen (H) Molecules and Compounds Figure 2-6: Electron configuration of the three most common elements in the body


Molecules and Compounds :Bonds capture energy Bonds link atoms Molecules Molecular weight Chemical formula Molecules and Compounds Figure 2-7b: Chemical structures and formulas of some biological molecules


Types of Chemical Bonds :Covalent bonds Common in biosystems Share a pair of electrons Ionic Bonds Transfer an electron Opposite charges attract Types of Chemical Bonds Figure 2-9a: Ions and ionic bonds


Types of Chemical Bonds :Hydrogen bonds Weak partial bonds Water surface tension Van der Waals forces - weak Types of Chemical Bonds Figure 10a: Hydrogen bonds of water


Functional Groups :Direct reactivity of a molecule Common examples in biosystems Functional Groups Table 2-1: Common Functional Groups


Slide 12:Polarity of Molecules Partial charges on regions of molecule Soluble in polar solvents ( i. e. H2O) Non polar molecules No regional partial charges Do not dissolve easily in water (i.e. lipids) Figure 2-8: Water is a polar molecule


Ionic Bonds and Ions :Ionic Bonds and Ions Ionic Bonds and Ions Gain 1 positive charge for each electron lost Gain 1 negative charge for each electron gained Dissolve and disassociate in polar solutions Important ions of the body Figure 2-9a : Ions and ionic bonds


Ionic Bonds and Ions :Ionic Bonds and Ions Table 2-2: Important Ions of the Body


Hydrogen Bonds (H-bonds) :Hydrogen Bonds (H-bonds) Strong polarity Attracts to self Surface tension Form droplets Thin films


Hydrogen Bonds (H-bonds) :Hydrogen Bonds (H-bonds) Figure 2-10: Hydrogen bonds of water


Solutions: Water is the main Solvent in Biosystems :Solutions: Water is the main Solvent in Biosystems Solutes dissolve in liquids Solvents dissolve solutes Solution: solute dissolves in solvent Solubility , ease of dissolving Hydrophobic Hydrophilic Figure 2-11: Sodium chloride dissolves in water


Concentrations :Amount of solute in a solution Mole defined Molarity–1 mole in 1 liter Equivalents–charge Weight /volume Grams solute/ml solvent Volume/volume Percent solution Concentrations


Hydrogen Ion Concentration (pH) in Biosystems :Hydrogen Ion Concentration (pH) in Biosystems Acid - contributes H+ to solution(CO2 + H2O H2CO3 H+ + HCO3- ) Base - decreases H+ in solution( NH3 + H2O NH4+ OH-) Buffer minimizes changes of pH


Hydrogen Ion Concentration (pH) in Biosystems :Hydrogen Ion Concentration (pH) in Biosystems Figure 2-12: pH scale


Carbohydrate Biomolecules: Carbon, Hydrogen & Oxygen :Complex carbohydrates: polymers (polysccharides) "Simple sugars" monosccharides (glucose, ribose) Carbohydrate Biomolecules: Carbon, Hydrogen & Oxygen


Carbohydrate Biomolecules: Carbon, Hydrogen & Oxygen :Carbohydrate Biomolecules: Carbon, Hydrogen & Oxygen Figure 2-13-1: Carbohydrates


Carbohydrate Biomolecules: Carbon, Hydrogen & Oxygen :Carbohydrate Biomolecules: Carbon, Hydrogen & Oxygen Figure 2-13-2: Carbohydrates


Lipids: Mostly Carbon and Hydrogen; little Oxygen :Triglycerides: Glycerol,Fatty acid chains Eicosanoids, Steroids & Phospholipids Lipids: Mostly Carbon and Hydrogen; little Oxygen


Lipids: Mostly Carbon and Hydrogen; little Oxygen :Lipids: Mostly Carbon and Hydrogen; little Oxygen Figure 2-14: Lipids and lipid-related molecules


Proteins: Amino acid polymers :Amino Acids: essential, amino group, acid group Protein structure: polypeptides, primary -quaternary Proteins: Amino acid polymers Figure 2-15: Amino acid structure


Combination Biomolecules :Lipoproteins (blood transport molecules) Glycoproteins (membrane structure) Glycolipids (membrane receptors) Combination Biomolecules Figure 2-19: Chemistry summary


Nucleotides, DNA and RNA :Composition Base Sugar Phosphate Transmit and store Information (genetic code) Energy transfer molecules ATP Cyclic AMP NAD & FAD Nucleotides, DNA and RNA


Nucleotides, DNA, and RNA :Nucleotides, DNA, and RNA Figure 2-18: RNA and DNA


Summary :Atoms: structure, mass, charge & orbitals Bonds: covalent, ionic, hydrogen Solutions: solutes, solvents, concentrations pH: hydrogen ions, acids, bases & buffering Biomolecules: carbohydrates, lipids, proteins & nucleic acids Summary