Analytical Chemistry Techniques

Analytical Chemistry

• Qualitative analysis identifies substances present in a sample.
• Quantitative analysis measures the amounts of substances in a sample.
• Titration is a technique using a titrant of known concentration.
• Titration gradually adds the titrant to a sample until the reaction reaches its equivalence point.
• Titration is used to determine an unknown concentration.
• Spectrophotometry measures how much light a sample absorbs.
• The amount of light absorbed is directly related to the concentration of the absorbing substance based on the Beer-Lambert law.
• Chromatography separates components in a mixture.
• Gas Chromatography (GC), Liquid Chromatography (LC) and Thin-Layer Chromatography (TLC) are common types of chromatography.
• The Limit of Detection (LOD) is the smallest concentration that can be detected, though not necessarily measured accurately.
• The Limit of Quantification (LOQ) is the smallest concentration that can be quantitatively measured with acceptable precision and accuracy.

General & Inorganic Chemistry

• The periodic table organizes elements by atomic number, electron configuration, and recurring periodic trends.
• Ionic bonds are formed by the transfer of electrons.
• Covalent Bonds are formed by the sharing of electrons.
• Metallic Bonds involve a "sea" of delocalized electrons.
• Secondary forces include hydrogen bonds and van der Waals interactions.
• Balancing Redox Reactions involves splitting the overall reaction into two half-reactions (oxidation and reduction).
• Each half-reaction must be balanced for mass and charge, then combined to cancel electrons.
• Oxidation state indicates how many electrons an atom gains, loses, or appears to share in a compound.
• Oxidation state is assigned based on standard rules for electron distribution in bonds.
• Ionic Compounds are formed from electron transfer.
• Ionic compounds typically have high melting points and conduct electricity in solution.
• Covalent Compounds are formed by sharing electrons.
• Covalent compounds often have lower melting points and do not conduct electricity well.

Organic Chemistry

• Functional groups are specific groups of atoms (e.g., hydroxyl, carbonyl, amino) that determine a molecule’s chemical reactivity and properties.
• Structural Isomers have the same formula but different connectivity.
• Stereoisomers have the same connectivity but different spatial arrangements of atoms.
• Nucleophilic Substitution Reaction is a reaction where a nucleophile replaces a leaving group.
• SN1 involves a two-step mechanism with a carbocation intermediate.
• SN2 involves a one-step, concerted mechanism with a backside attack.
• Electrophilic Addition Reaction occurs in alkenes where an electrophile attacks the double bond.
• Aromaticity is a property of cyclic, planar molecules with a conjugated pi-electron system.
• To be aromatic, a molecule must meet Huckel’s rule (having 4n + 2 π electrons), which gives it extra stability.

BIO/09: Physiology

• Homeostasis is the process by which living organisms maintain a stable internal environment despite external changes.
• Hormones are chemical messengers released by endocrine glands that regulate metabolism, growth, stress responses, and other body functions.
• The cell membrane is a lipid bilayer embedded with proteins.
• The cell membrane controls the entry and exit of substances, and facilitates communication and transport.
• The circulatory system transports oxygen, nutrients, and waste products through the body using blood and blood vessels.
• The respiratory system facilitates gas exchange in the lungs, where oxygen is absorbed into the blood and carbon dioxide is expelled.

BIO/10, BIO/11, BIO/13: Biochemistry; Molecular Biology; Applied Biology

• The Central Dogma of Molecular Biology describes the flow of genetic information: DNA → RNA → Protein.
• A nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.
• Enzymes are proteins that act as catalysts to speed up biochemical reactions by lowering the activation energy.
• Enzymes are highly specific.
• DNA Replication is a semi-conservative process where each strand of the DNA serves as a template for the formation of a new complementary strand.
• DNA replication involves enzymes like DNA polymerase.
• Transcription is the synthesis of RNA from a DNA template.
• Translation is the assembly of proteins using the mRNA template.
• Gene Expression Regulation is controlled by DNA elements such as promoters, enhancers, and repressors.
• Epigenetic modifications influence when and how genes are expressed, and also control Gene Expression Regulation .
• Carbohydrates are biomolecules that serve as energy sources and provide structural support (e.g., in cell walls).
• Proteins have different levels of structure; Primary, secondary, tertiary and quaternary.
• Primary Protein structure is its amino acid sequence.
• Secondary Protein structure is folding into patterns like alpha-helices or beta-sheets.
• Tertiary Protein structure is its three-dimensional shape.
• Quaternary Protein structure is the assembly of multiple protein subunits.
• Lipids are involved in energy storage, forming cell membranes, and serving as signaling molecules.
• Adenosine triphosphate (ATP) stores and transfers energy within cells for metabolic processes.
• Metabolic Pathways are a series of enzyme-catalyzed reactions that convert substrates into products.
• Glycolysis converts glucose into pyruvate to produce energy.
• Signal Transduction is the process by which cells detect and respond to external signals through receptors and intracellular pathways.
• Signal Transduction allows for coordinated cellular responses.

BIO/14: Pharmacology/Toxicology

• Pharmacokinetics studies how drugs move through the body, covering four main components: Absorption, Distribution, Metabolism, and Excretion (ADME).
• Pharmacodynamics explains how drugs affect the body, focusing on receptor interactions, binding, and the resulting dose-response relationships.
• Common Methods of drug administration include oral, intravenous, intramuscular, subcutaneous, and topical delivery.
• Drugs can bind to receptors as Agonists or Antagonists.
• Agonists activate the receptor.
• Antagonists block the receptor.
• The strength of binding (affinity) affects the drug’s effect.
• Toxicity is determined by measuring how a drug’s effect changes with dose, using tools like dose-response curves, LD50 (lethal dose for 50% of the population), and safety margins.
• Side Effects are typically expected, sometimes minor effects that occur alongside the primary action of a drug.
• Adverse Effects are harmful, unintended reactions that can be serious.