Water Reviewer PDF

WATER  These are made from a weak acid and its salt WATER (conjugate base)  has several unique properties that make it BASIC BUFFERS essential for life...

WATER  These are made from a weak acid and its salt WATER (conjugate base)  has several unique properties that make it BASIC BUFFERS essential for life  These are made from a weak base and its salt  WATER’S POLARITY IS DUE TO THE (conjugate acid) UNEVEN DISTRIBUTION OF ELECTRONS EXAMPLES OF BUFFERS IN LIVING BETWEEN OXYGEN AND HYDROGEN ORGANISMS ATOMS. BICARBONATE BUFFER SYSTEM  the predominant chemical component of living  This system helps maintain the pH of blood. organisms. Its unique physical properties,  The bicarbonate buffer system consists of which include the ability to solvate a wide carbonic acid (H₂CO₃) and bicarbonate ions range of organic and inorganic molecules, (HCO₃⁻), which help regulate blood pH derive from water’s dipolar structure and PHOSPHATE BUFFER SYSTEM exceptional capacity for forming hydrogen  This system operates in the internal fluids of bonds. cells. It helps maintain pH by neutralizing excess H⁺ ions with hydrogen phosphate or  Solvent excess OH⁻ ions with dihydrogen phosphate1  Cohesion  the phosphate buffer system operates mainly  Adhesion within cells.  High Specific Heat  High Heat of Vaporization PROTEIN BUFFER SYSTEM  Density  Proteins can act as buffers by accepting or  Polarity-PROPERTY OF WATER ALLOWS donating H⁺ ions. For example, hemoglobin in IT TO DISSOLVE MANY SUBSTANCES red blood cells helps buffer blood pH by The Covalent Bond binding to H⁺ ions1.  the strongest force that holds molecules together. Hydrophobic Interaction HEMOGLOBIN BUFFER SYSTEM  refers to the tendency of nonpolar compounds  Hemoglobin can bind to both oxygen and to self-associate in an aqueous environment. hydrogen ions. When the blood becomes too Electrostatic Interaction acidic, hemoglobin binds to excess H⁺ ions,  between oppositely charged groups within or helping to maintain pH balance. During between biomolecules are termed salt bridges. exercise, when more H⁺ ions are produced, SOLVENT hemoglobin helps buffer these ions1.  Water is known as the “universal solvent” because it can dissolve many substances. This HENDERSON-HASSELBALCH EQUATION is important for biochemical reactions in our  is used to estimate the pH of a buffer solution. bodies, as it helps transport nutrients and waste  equation: pH=pKa+log([HA][A−]​ ) products. BUFFERS Where:  are crucial in maintaining the pH balance in pH: The measure of acidity or basicity of the biological systems. solution.  A buffer is a solution that resists changes in pH pKa: The acid dissociation constant, a value that when small amounts of acid or base are added. indicates the strength of the acid.  It usually consists of a weak acid and its  pKa is used to express the relative strengths of conjugate base or a weak base and its conjugate both weak acids and weak bases using a single, acid. unified scale.  Buffers can neutralize both acids and bases, A−: The concentration of the conjugate base. maintaining a stable pH by reacting with added HA :The concentration of the weak acid. H⁺ or OH⁻ ions. HOW BUFFERS WORK: The pH ACIDIC BUFFERS  The term pH was introduced in 1909 by Sörensen, who defined it as the negative log of the hydrogen ion concentration:  This value is also known as the power (English), puissant (French), or potennz (German) of the exponent, hence the use of the term “p.”  Low pH values correspond to high concentrations of H+ and high pH values correspond to low concentrations of H+. Acids are proton donors. Strong acids  (eg, HCl, H2SO4) completely dissociate into anions and protons even in strongly acidic solutions (low pH). Weak acids  dissociate only partially in acidic solutions. Many biochemicals are weak acids Bases are proton acceptors. Strong bases  (eg, KOH, NaOH), but not weak bases like Ca(OH)2, are completely dissociated even at high pH.