Chapter 2 Flashcards
Atom
Smallest stable unit of matter.
Subatomic Particles
Particles composing an atom: protons, neutrons, electrons.
Proton
Positively charged subatomic particle in nucleus.
Neutron
Neutral subatomic particle in nucleus.
Electron
Negatively charged particle orbiting the nucleus.
Atomic Number
Number of protons in an atom’s nucleus.
Nucleus
Center of the atom containing protons and neutrons.
Electron Cloud
3D area where electrons orbit the nucleus.
Electron Shell
2D representation of electron cloud layers.
Valence Shell
Outermost electron shell determining chemical bonding.
Octet Rule
Atoms are stable with 8 electrons in valence shell.
Molecule
Chemical structure of 2+ atoms sharing electrons.
Compound
Substance with atoms from at least two elements.
Ionic Bond
Bond formed by complete transfer of electrons.
Cation
Positively charged ion that donates electrons.
Anion
Negatively charged ion that accepts electrons.
Ion
Atom with an electric charge due to electron loss/gain.
Covalent Bond
Bond formed by sharing electrons between atoms.
Single Covalent Bond
Bond formed by sharing one pair of electrons.
Double Covalent Bond
Bond formed by sharing two pairs of electrons.
Triple Covalent Bond
Bond formed by sharing three pairs of electrons.
Nonpolar Covalent Bond
Equal sharing of electrons between identical atoms.
Polar Covalent Bond
Unequal sharing of electrons between different atoms.
pH
Measure of acidity or alkalinity in solutions.
Buffer
Substance that stabilizes pH in body fluids.
ATP
Adenosine triphosphate, energy currency of cells.
Nucleic Acids
Molecules that store and transmit genetic information.
Water
Essential compound with unique chemical properties.
Acid
Substance that donates protons in solution.
Base
Substance that accepts protons in solution.
Salt
Ionic compound formed from acid-base reactions.
Polar covalent bonds
Bonds in a water molecule where the oxygen atom holds the electrons more tightly than the hydrogen atoms.
Hydrogen bonds
Weak polar bonds between adjacent molecules based on electrical attractions.
Chemical reaction
Process that involves the rearrangement of the molecular or ionic structure.
Reactants
Starting material that undergo a chemical change to form a product.
Products
Substance made by the chemical reaction.
Metabolism
Chemical reactions in the body’s cells that change food into energy.
Decomposition Reaction
Breakdown of a molecule into smaller parts.
Hydrolysis Reaction
Water molecule breaks down a complex molecule.
Synthesis Reaction
Chemical process where 2 or more simple elements/compounds combine to form a more complex product.
Enzymes
Protein catalysts that accelerate biochemical reactions by lowering the activation energy.
Activation energy
The minimum amount of energy needed to start a reaction.
Metabolic Pathways
Sequence of enzyme reactions that lead to the conversion of a substance into a product.
Inorganic compounds
Generally, lack carbon-hydrogen bonds.
Organic compounds
Generally, contain carbon-hydrogen bonds.
Water (H2O)
Accounts for up to two-thirds of total body weight and is a universal solvent.
Solvent
The dissolving medium (water).
Solute
Substance that is being dissolved.
Solution
Mixture consisting of a solute dissolved into a solvent.
Dissociation
Splitting into smaller molecules.
Ionization
Splitting into ions.
Electrolytes
Soluble inorganic substances that break down into ions when dissolved in water or body fluids.
Hydrophilic Compounds
Compounds that interact with water due to polar covalent bonds.
Hydrophobic Compounds
Compounds that lack affinity for water and repel it.
Neutral pH
A balance of H+ and OH-, with a value of 7.0.
Acidic pH
Lower than 7.0, indicating high H+ concentration.
Basic pH
Higher than 7.0, indicating low H+ concentration.
Acidosis
Low blood pH (more acidic).
Alkalosis
High blood pH (more basic).
Respiratory Acidosis
Condition from inadequate CO2 removal by lungs.
Hypoventilation
Decreased respiration leading to lower blood pH.
Respiratory Alkalosis
Condition from excessive CO2 removal, raising blood pH.
Hyperventilation
Increased respiration due to anxiety or fever.
Metabolic Acidosis
Excess acid production or insufficient acid removal.
Metabolic Alkalosis
Excess bicarbonate or loss of stomach acid.
Buffers
Compounds stabilizing pH by neutralizing acids/bases.
Antacids
Sodium bicarbonate neutralizes stomach hydrochloric acid.
Protein Buffer System
Proteins regulate pH by absorbing/releasing H+ ions.
Hemoglobin Buffer System
Maintains blood pH via red blood cell proteins.
Carbonic Acid-Bicarbonate Buffer System
Regulates blood pH through bicarbonate and carbonic acid.
Phosphate Buffer System
Maintains pH levels in cells and fluids.
Lipids
Hydrophobic molecules including fats, oils, and waxes.
Energy Storage
Lipids provide double energy compared to carbohydrates.
Phospholipids
Contain diglycerides and phosphate groups, forming membranes.
Glycolipids
Contain diglycerides and sugars, aiding cell recognition.
Micelles
Formed by phospholipids in water with hydrophilic heads.
Proteins
Most abundant organic molecules composed of amino acids.
Amino Acids
Building blocks of proteins with central carbon structure.
Cofactors
Molecules required for enzyme activity.
Denaturation
Loss of protein structure and functionality.
DNA
Contains genetic instructions for protein synthesis.
RNA
Involved in protein synthesis using DNA information.
Nucleotides
Monomers of nucleic acids with sugar, phosphate, base.
Purines
Double-ringed nitrogenous bases: adenine and guanine.
Pyrimidines
Single-ringed nitrogenous bases: cytosine, thymine, uracil.
Phosphorylation
Adding phosphate group to produce high-energy bonds.
ATPase
Enzyme converting ATP to ADP, releasing energy.
