Key Concepts for Week 1: Lectures 1-4 Friday, Sept. 25, Lecture 1: Introduction, Themes in Biology Life is composed of many themes, or emergent properties o Form fits function (ex. A bird’s wing) Basic unit of life = cell o All cells have a membrane and use DNA as genetic information Monday, Sept. 28, Lecture 2: Atoms, Molecules and Water Cell is the lowest functioning unit of life o Composed of molecules, formed by the collection of atoms Two types of chemical bonds: o Strong Covalent Nonpolar (equal sharing of electrons, like Oxygen) Polar (unequal sharing of electrons, like water) Ionic o Weak Hydrogen Molecular structure of water o Water can have different interactions among itself (cohesion) or with other molecules (solvent) Acidity and basicity (pH scale) o Buffers maintain pH of solutions (ex. Blood buffered by bicarbonate and carbonic acid) Wednesday, Sept. 30, Lecture 3: Carbons, Carbohydrates and Lipids Most living elements made up of carbon o Huge diversity with carbon compounds Number of carbon, bonds, functional groups that bind onto carbons Hydroxyl, carbonyl, etc. Carbon based molecules built from similar subunits: o Carbohydrates Mono/di/poly- saccharide o Proteins (more detail in Lecture 4) o Nucleic acids (more detail in Lecture 4) Carbon based molecules built from different subunits: o Lipids Fats Saturated or unsaturated Phospholipids Remember cell membrane layer Steroids Cholesterol Assembly / disassembly of polymers o Polymerase (condensation reaction/ dehydration) or hydrolase (hydrolysis reaction/ addition of water) Friday, Oct. 2, Lecture 4: Proteins and Nucleic Acids Proteins o Structure: made up of amino acids (carbon, amino, hydrogen, carboxyl) Different side chains (hydrophilic, hydrophobic, ionized) o Various functions in cells o Function of protein depends on its structure – different levels Primary (actual AA sequence) Secondary (alpha helix or beta sheets) Tertiary (side group interactions) Quaternary (association with other peptides) o Damaged proteins actively degraded by proteasome Nucleic acids (DNA makeup) o Structure: nucleotides (pentose sugar, nitrogen, phosphate group) DNA or RNA o Function – basis of inheritance What bonds make up protein and DNA structure???