Key Concepts for Week 1: Lectures 1-4
Friday, Sept. 25, Lecture 1: Introduction, Themes in Biology
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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
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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
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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
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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
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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???