CSU CHEM 103 EXAM @ STUDY GUIDE

Water

• Density of Ice: Ice is less dense than liquid water due to its molecular structure, causing it to float.

• Water as a Polar Solvent: Water is polar, meaning it has a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom, which allows it to dissolve ionic and polar compounds.

• How Ions Dissolve in Water: Water molecules surround ions, creating a stable solution due to ion-dipole interactions.

• Why Non-Polar Substances Don’t Dissolve in Water: Non-polar molecules lack a charge, so they don’t interact with the polar water molecules, preventing dissolution.

• Role of Entropy: Entropy drives the dissolution of substances in water, as it increases the randomness of the system. The increase in disorder makes the process energetically favorable.

Intermolecular Forces

• Ion-Dipole Interactions: Occur between an ion and a polar molecule.

• Hydrogen Bonding: A strong dipole-dipole interaction that occurs when hydrogen is bonded to electronegative atoms like oxygen, nitrogen, or fluorine.

• Dipole-Dipole Interactions: Interactions between the positive and negative ends of polar molecules.

• Van der Waals Interactions: Weak attractions due to temporary dipoles formed when electrons move around atoms.

Molecules of Life

• Four Molecules of Life:

  1. Fats (Lipids)

  2. Sugars (Carbohydrates)

  3. Proteins

  4. DNA/RNA

• Matching Structures with Functions:

  • Fats/Lipids: Provide energy storage, cell membrane structure, and insulation.

  • Sugars/Carbohydrates: Provide energy and structural support.

  • Proteins: Catalyze biochemical reactions, provide structure, and regulate body functions.

  • DNA/RNA: Store and transmit genetic information.

Functional Groups

• Alcohol: -OH group.

• Carboxylic Acid: -COOH group.

• Ester: -COO- group.

• Aromatic: A benzene ring (C6H6).

• Aldehyde: -CHO group.

• Olefin (Carbon-Carbon Double Bond): C=C bond.

• Methyl (–CH3): A methyl group.

• Ethers: -O- between two carbon atoms.

• Amines: -NH2 group.

• Amides: -CONH2 group (formed via condensation between carboxylic acid and amino acid).

Lipids/Fats

• Identify Structures and Functions:

  • Steroids: Hormones, cell membrane structure (e.g., cholesterol).

  • Terpenes: Form essential oils and pigments.

  • Cannabinoids: Signaling molecules in the body, found in cannabis.

Sugars/Carbohydrates

• Types:

  • Glucose, Fructose, Sucrose: Monosaccharides and disaccharides.

• Biological Roles: Provide energy and structural components (e.g., cellulose).

• Starch vs. Cellulose:

  • Starch (Alpha Linkages): Digestible by humans.

  • Cellulose (Beta Linkages): Cannot be digested by humans.

• Why Can Some Eat Cellulose: Certain animals, like cows, have bacteria in their gut that can break down cellulose.

• Enzymes:

  • Amylase: Breaks down starch.

  • Cellulase: Breaks down cellulose.

• Lactose Intolerance: Due to a lack of the enzyme lactase that breaks down lactose.

Proteins

• Biological Roles: Enzyme catalysis, structural support, signaling, and transport.

• Protein Folding: Hydrophobic amino acids are on the inside, hydrophilic ones on the outside.

• Amino Acids: Composed of an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a side chain (R group).

• Peptide Bond: Links amino acids in proteins.

• Levels of Protein Structure:

  1. Primary: Sequence of amino acids.

  2. Secondary: Alpha helices and beta sheets.

  3. Tertiary: 3D shape of the protein.

  4. Quaternary: Multiple polypeptide chains interacting.

• Essential Amino Acids: Amino acids that must be obtained from the diet.

Nucleic Acids

• Nucleotide Structure: Composed of a phosphate group, a sugar (ribose or deoxyribose), and a nitrogenous base (A, T, C, G for DNA, A, U, C, G for RNA).

• DNA vs. RNA:

  • DNA: Double-stranded, deoxyribose, thymine (T).

  • RNA: Single-stranded, ribose, uracil (U).

• Base-Pairing Rules: A-T (DNA), A-U (RNA), C-G.

• Genetic Information Flow: DNA → RNA → Protein.

• Replication, Transcription, Translation: Processes to copy, transcribe, and translate genetic information.

• Ribosomes and tRNA: Involved in protein synthesis.

Vitamins

• General Characteristics: Organic compounds essential for normal growth and nutrition.

• Water-Soluble vs. Fat-Soluble:

  • Water-Soluble: B-vitamins, Vitamin C.

  • Fat-Soluble: Vitamins A, D, E, K.

NSAIDs

• Prostaglandin Synthesis and COX Enzymes:

  • COX-1: Involved in protecting the stomach lining.

  • COX-2: Induced during inflammation.

• NSAIDs as COX Inhibitors: Block COX enzymes to reduce pain and inflammation.

• COX-2 Specific Inhibitors: Designed to target inflammation without affecting stomach protection.

Sickle Cell Disease

• Genetic Cause: A mutation in the hemoglobin gene leads to sickle-shaped red blood cells.

• Hydrophobic Amino Acid: The mutation causes a hydrophobic amino acid to be exposed, leading to aggregation and sickling.

• Pathology: Sickled cells block blood flow, causing pain and organ damage.

COVID-19

• Structure: SARS-CoV-2 virus with spike proteins for cell entry.

• Vaccines: Stimulate immune response to prevent infection.

• How Vaccines Work: Trigger the immune system to recognize and fight the virus.

Polymers

• Natural vs. Synthetic Polymers:

  • Natural: Cellulose, keratin, silk.

  • Synthetic: Polyethylene, nylon, PVC, rubber.

• Addition vs. Condensation Polymerization:

  • Addition: Monomers with unsaturated bonds (e.g., polyethylene).

  • Condensation: Monomers with functional groups (e.g., nylon).

• Free-Radicals: Unstable molecules that initiate polymerization.

• Municipal Solid Waste: Includes plastic, paper, and food waste; alternatives include recycling and composting.