Acids/Bases & Organic/Inorganic

Acidic, basic, and neutral solutions

• Acids: cause more H⁺ in a solution

  • LESS than pH 7

• Bases: cause more OH^- in a solution

  • GREATER than pH 7

• Neutral: H⁺ = OH^-

  • = pH 7

• pH: a scale that measures how acidic or basic a solution is.

• Bases can neutralize acids: excess H⁺ ions get eliminated by OH^- to form H₂O.

• Acid + Base → Water + Salt
  → Ex: HCl + NaOH → H₂O + NaCl

Buffers

• Absorb EXCESS acid or base to keep pH constant (important for homeostasis).

• Blood pH must be kept between 7.35 and 7.45.

• Stomach enzymes only function when the pH is kept between 2 - 4.

• Buffers do not necessarily make solutions neutral, but the solution is at a certain pH level.

Organic & Inorganic compounds

• Organic compounds: always contain C (and usually H) and have covalent bonding.

  → Ex: C₆H₁₂O₆ (glucose), CO₂

• Inorganic compounds: usually have ionic bonding (between metals & non-metals) and have a small number of atoms (usually).

  • Essentially, inorganic compounds are “everything else”.

• Living things are made up mostly of 6 elements.

  → C, H, O, N, P, S = 98% of mass

  → also Cl, Mg, Ca, K, Na, Fe, I, and other trace elements (C. HOPKINS Cafe)

Hydrolysis vs. Dehydration synthesis

• Most compounds in the body are formed by joining subunits (monomers) into chains (polymers).

• Hydrolysis: a chemical reaction where water breaks a large molecule into 2 or more smaller ones.

• Dehydration synthesis: two small molecules join together to form a larger molecule, releasing a molecule of water in the process.

  • Amino acids form proteins.

  • Sugars form carbohydrates.

  • Nucleotides form nucleic acids.

  • Fatty acids and glycerol form lipids (aka “fats”).