BIOL 103: The Chemistry of Life & Science Basics

Five Properties of Life

Growth, reproduction, homeostasis, sensing/responding to stimuli, and using energy.

Why Viruses Aren't Alive

They are non-cellular and unable to replicate on their own.

Estimated Age of Earth

Approximately 4.5 billion years old.

Radiometric Dating

Measures the radioactive decay of isotopes to date rocks.

Miller-Urey Experiment

Showed organic molecules can form from inorganic molecules on early Earth.

Atom

The smallest unit of an element.

Atomic Number

The number of protons in an atom's nucleus.

Isotopes

Variants of an element that differ in the number of neutrons.

Molecule vs Compound

A compound is a molecule that must contain at least two different elements.

Ionic Bond

A chemical bond where electrons are donated from one atom to another.

Covalent Bond

A chemical bond where two atoms share pairs of electrons.

Polar vs Nonpolar Covalent Bonds

Nonpolar involves equal electron sharing; polar involves unequal sharing.

Hydrogen Bond

A weak electrostatic attraction between polar molecules involving H bonded to N, O, or F.

Why Ice Floats

Stable hydrogen bonds form an expanded, less dense crystalline lattice.

Water Cohesion

Water molecules cling together, creating surface tension.

Water Adhesion

Water molecules cling to surfaces of other polar molecules.

Hydrophilic vs Hydrophobic

Hydrophilic dissolves in water ("water-loving"); hydrophobic does not ("water-fearing").

pH Scale Range and Function

Ranges from 0 to 14; acids donate H+ ions, bases accept H+ ions.

Organic vs Inorganic Molecules

Organic molecules have carbon backbones and C-H bonds; inorganic lack them.

Dehydration Reaction vs Hydrolysis

Dehydration links monomers into polymers; hydrolysis breaks polymers apart using water.

Four Types of Macromolecules

Carbohydrates, lipids, proteins, and nucleic acids.

Carbohydrate Function

Polymers of sugar that provide primary and time-released energy.

Protein Monomers

Amino acids.

Lipid Energy Content

Provide more than twice as much energy per gram (9 calories) as carbs/proteins (4 calories).

Triglyceride Structure

One glycerol head region attached to three fatty acid tails.

Phospholipids

Lipids that serve as the main building blocks of cell membranes.

Nucleic Acid Monomers

Nucleotides.

Two Main Nucleic Acids

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).