Chemistry Lecture 3 Flashcards
INORGANIC COMPOUNDS AND BODY FLUIDS
Inorganic Compounds, Organic Compounds, Water, Fluid Distribution
Inorganic Compounds: Inorganic compounds do not contain carbon and are usually simple.
Organic Compounds: Always contain carbon and hydrogen.
Water: Essential for survival, important for chemical reactions, and medium for nearly all reactions.
Fluid Distribution: Males have approximately 60% of body mass as water, females have about 55%.
Intracellular Fluid (ICF)
Location, Proportion
Location: Fluid inside cells, part of the cytoplasm.
Proportion: About 2/3 of the body’s water is intracellular.
Extracellular Fluid (ECF)
Location, Proportion
Location: Outside of cells.
Proportion: About 1/3 of the body’s water is extracellular.
Interstitial Fluid
Definition, Proportion
Definition: Fluid between cells but not in the blood.
Proportion: Approximately 80% of ECF.
Plasma
Definition, Proportion
Definition: The liquid component of blood.
Proportion: About 20% of ECF.
Important Properties of Water
Essential for Life: Key for human and all life.
Solvent: Water is a universal solvent for life.
Chemical Reactant: Most common medium for chemical reactions.
Heat Capacity: Has a high heat capacity.
Lubricant: Useful for reducing friction between surfaces.
Water as a Lubricant
Friction Reduction: Little friction between water molecules, so thin layer of water reduces friction between surfaces.
Useful for Joints: Helps with joint movement.
Useful for Body Cavities: Reduces friction in body cavities
Solvent Properties of Water
Definition of solute, solvent, etc…
Definition: Solutions are made up of solvents (the liquid factor) and solute.
Solvent Defined: A solvent is an aqueous component with the ability to dissolve (the liquid factor).
Solute Defined: The solute is the substance being dissolved (particle or molecule).
Example: Water + salt. What happens when they mix? Which is the solvent and which is the solute?
Water as a Universal Solvent
Definition: Water is the universal solvent for life.
Importance: Water acting like a strong solvent allows the body to keep certain substances dissolved in both ECF and ICF.
Substances:Important molecules such as gases like oxygen and carbon dioxide, nutrients such as glucose, electrolytes like Na+ and Cl- that are essential to bodily functions, and hormones which send signals throughout the body.
How Water Acts as a Solvent
Polarity
Polarity:Water is a polar molecule.
Hydrogen Bonds: Oxygen in water is highly electronegative and pulls electrons away from the hydrogen atoms.
Result: This creates a very polar molecule. The positive poles of the hydrogens can interact with negative molecules, and the negative poles of the oxygen can interact with positive molecules.
Hydrophilic and Hydrophobic Molecules
Definitions: Hydrophilic molecules are polar or charged. Hydrophobic molecules are non-polar or carry no charge.
Interactions with Water: Hydrophilic molecules “like” interacting with water, while hydrophobic molecules do not.
Examples: Glucose and salts are hydrophilic, while fats and oils are hydrophobic.
Absorption: These characteristics are the basis of all absorbent properties of nutrients, vitamins, fats, sugars, salts, hormones, and drugs in our bodies.
Mixture
Definition: A combination of physically blended elements and/or compounds that are not held together by chemical bonds.
Example: The air we breathe is a mixture of O2, H2, N2, & CO2.
Liquid Mixtures
Types: Solutions, Colloids, Suspensions
Solutions: A liquid mixture where the solute (minor component) is uniformly distributed within the solvent (major component). Particles are < 1 nm and cannot be seen with the naked eye.
Colloids: A solution where the solutes are large enough to scatter light. Particle size is 1 nm to 1000 nm.
Suspensions: A mixture of solutes within a solution which settle out over time into their different components. Particle size is > 1000 nm.
Viscosity
Definition: A measure of a fluid’s resistance to flow.
Thicker vs. Thinner: Thicker substances have more viscosity and flow slower. Thinner substances have less viscosity and flow faster.
The Concentration of Solutions
Definition:The concentration of a solution can be expressed in several ways, including mass per volume percentage and molarity.
Mass per Volume Percentage: Example: “Alcohol 5% by volume”.
Molarity: A measure of concentration in units of moles per liter (mol/L). It is related to the total number of molecules in a given volume of solution.
Avogadro’s Number: 6.022 x 10^23, which is the number of particles in a mole of a substance.
Acids and Bases
Definition: Acids release hydrogen ions (H+) and bases remove hydrogen ions from solution.
Water Dissociation: Water can dissociate into hydrogen ions (H+) and hydroxide ions (OH-).
pH Scale:Measures the concentration of H+ ions in a solution. Ranges from 0 to 14.
Acidic: Below 7, contains more H+ than OH-.
Neutral: 7, contains equal H+ and OH-.
Basic: Above 7, contains more OH- than H+.
Acids
Definition: Acids are solutes that dissociate and release hydrogen ions (H+).
Proton Donors: Acids are often referred to as proton donors.
Strong Acids: Dissociate completely in solution (e.g., hydrochloric acid, HCl).
Bases
Definition: Bases are solutes that remove hydrogen ions (H+) from solution.
Proton Acceptors:Bases are often referred to as proton acceptors.
Strong Bases: Dissociate completely in solution (e.g., sodium hydroxide, NaOH).
Weak Acids and Bases
Definition: Weak acids and bases fail to dissociate completely in solution.
Impact on pH:They have less of an impact on pH than strong acids and bases.
Example: Carbonic acid (H2CO3).
Salts
Definition: Salts are inorganic compounds composed of any cation (except hydrogen) and any anion (except hydroxide).
Ionic Bonds: Held together by ionic bonds.
Dissociation: Many salts dissociate completely in water, releasing cations and anions (e.g., NaCl).
Buffer Systems
Definition: Chemical systems composed of compounds that help regulate pH in biological systems by removing excess hydrogen ions (H+).
Importance: Buffers maintain narrow limits of pH in body fluids, crucial for proper function.
Examples: Carbonic Acid - Bicarbonate System, Phosphate Buffer System, Proteins as a Buffer System.
Carbonic Acid - Bicarbonate System
Components: Carbonic acid (H2CO3) and bicarbonate (HCO3-).
Function: Bicarbonate ions act as weak bases and carbonic acid as a weak acid.
Balance: Bicarbonate ions combine with excess H+ to form carbonic acid, which can then release H+ ions.
Control: Controlled by expiration of CO2 through lungs and renal system.
Phosphate Buffer System
Components: Phosphates (PO4^3-) in two forms: Dihydrogen phosphate (H2PO4-) and Monohydrogen phosphate (HPO4^2-).
Function: Similar to bicarbonate system, phosphates act as weak acids or weak bases.
Control: Helps maintain pH in blood and other body fluids.
Proteins as a Buffer System
Components: Proteins such as albumin in plasma and hemoglobin in red blood cells.
Function: The amine group of amino acids buffers acids, while the carboxyl group buffers bases.
Importance: Critical for maintaining pH in blood and other body fluids.
