Carbon Compounds and the Chemistry of Life

• Chapter 3 delves into the Chemistry of Life.

Objectives

• Compare the different types of bonds that form molecules.
• Diagram hydrogen bonds between water molecules, explaining how the bonds produce water's unique properties.
• Describe the four major classes of biomolecules, their roles in biological systems, and their structure and function.
• Graphically show how the major classes of biomolecules (and their subunits) are related.
• Explain the difference between hydrophilic and hydrophobic molecules and the difference between acids and bases.
• Predict a solution's free hydrogen ion concentration using its pH number.
• Describe the chemical qualities of carbon that make it the basis of life on Earth.

Breaking Good

• The story highlights chemists racing to design safer opioid painkillers to combat overdose deaths.
• Edwin Chindongo, originally from Zimbabwe, was diagnosed with nerve damage from diabetes - he was prescribed oxycodone (opioid pain reliever).
• Edwin became addicted to oxycodone after dosage increases by his doctor and began using it more often than prescribed.

A Growing Epidemic

• Opioid addiction is epidemic in America.
• Over 130 people die every day from an opioid overdose.
• Opioid overdose death rates increased dramatically during the COVID-19 pandemic.

Origins of Life

• Life: anything that has mass, occupies space
• Element: a pure substance with distinct physical and chemical properties that cannot be broken down into other substances
• Atom: The smallest unit of an element retaining its distinctive properties

Parts of And Atom

• Atom: made of closely bound protons and neutrons
• Nucleus: where protons and neutrons are packed
• Positively charged nuclear particles: protons
• Uncharged nuclear particle: neutrons (neutral)
• Electrons: negatively charged particles surrounding the nucleus

Elements

• Atomic number: the number of protons in an atom's nucleus, unique to each element
• Isotopes: have the same number of protons, different numbers of neutrons
• Mass number: sum of the number of protons and neutrons in an isotope
• Atomic mass: the amount of mass in an isotope of an element

Chemical Bonds

• Chemical bonds attach atoms together.
• Electronegativity: the attraction (pull) for shared electrons
• Differences in electronegativity can give "polarity" of the bond.

Chemical Bonds - Introduction

• Chemical bonds attach atoms together via ionic, covalent, and hydrogen bonds.
• Covalent bond: formed when two atoms share electrons in their outermost electron shell (the valence shell)
• Covalently bonded electron pairs are shared equally, so charge is evenly distributed.
• Polar covalent bond: electron pairs are not shared equally, so atoms have partial charges.

Ionic Bonds

• Ionic bond: Formed when the charges of positive and negative ions hold the atoms together through the transfer of one or more valence electrons.
• Ions: Atoms that have lost or gained valence electrons during ionic bonding.

Hydrogen Bonds

• Hydrogen bond: A weak electrical attraction formed between two molecules, each of which has a polar covalent bond(s).
• Partial positive hydrogen of one molecule is attracted to the partial negative atom of another molecule.
• Hydrogen bonding the electrical attraction between a partially postive hydrogen atom and the partially negative atom.

Edwin's Story

• Tolerance: when a person no longer responds to a drug in the same way and must take a larger dose to achieve the same response
• Withdrawal: physical or psychological symptoms when a person stops taking an addictive drug
• Addiction: drug use that remains compulsive despite negative consequences
• After rehab and post-detox program: Edwin is has been sober!

Molecules and Compounds

• Chemical compound: molecules that contain atoms from at least two different elements in a fixed ratio
• Organic molecules: molecules that contain at least one carbon atom and hydrogen atoms
• Biological compounds: multiple organic molecules bound together

Carbon

• No other element is as versatile as carbon.
• A single carbon atom forms strong covalent bonds with up to four other atoms.
• Carbon atoms bound to other carbon atoms form long chains, branched molecules, and rings.

Biomolecules

• Macromolecules: large organic molecules
• Four major classes of biomolecules for living cells: proteins, carbohydrates, nucleic acids, and lipids
• All constructed on a framework of covalently bonded carbon atoms.

Polymers

• Polymers: long strands of repeating units of small molecules named monomers
• Polymers include proteins, carbohydrates, and nucleic acids.

Proteins

• Proteins: The most numerous and versatile of the major classes of biomolecules.
• Proteins: made of different combinations of the 20 amino acid monomers
• Proteins vary in structure, making them capable of enzymatic functions, structural, hormonal, membrane transport proteins, antibodies, and storage proteins

Carbohydrates

• Carbohydrates: Made of sugar monomers
• Carbohydrates range in size from one monomer to thousands.
• Monosaccharide: One monomer.
• Disaccharide: two monomers
• Polysaccharides up to thousands of monomers

Function of Carbohydrates

• Vary in size and shape, therefore function
• Simple sugars: cell's fuel for ATP
• Energy storage: glycogen
• Structural support: chitin or fiber, peptidoglycan

Nucleic Acids

• Nucleic acids Polymers of nucleotides: deoxyribonucleotides (DNA) and ribonucleotides (RNA)
• DNA: built of two strands of joined nucleotides containing long-term, stable genetic information.
• RNA: made of single strands of nucleotides providing a readable genetic language that has a function in enabling translation as proteins.

Lipids

• Lipids: best known as fats, oils, and steroids
• Lipids consist of hydrocarbons, fatty acids, and/or glycerol.
• Lipids function in: energy storage, insulation, structural support, protection, and communication.

Polar Molecules

• Polar molecules: covalently bonded atoms in a molecule share electrons unequally
• Water is an example
• Oxygen end takes on a slightly negative charge, and the hydrogen ends become slightly positively charged.
• Hydrogen bonds: A molecule with a partial negative atom can form hydrogen bonds with water.

Water

• Water: compounds mix completely

Solvents

• Polarity makes water good at dissolving other substances into solutions.
• Solution: a combination of a solute and a solvent
• Solute: dissolved substance
• Solvent: fluid into which the solute dissolves
• Water: "versatile solvent" because it dissolves so many substances

Hydro and Hydrophobic Substances

• Hydrophilic: a substance that dissolves in water
• Hydrophobic: a substance that does not dissolve well in water

States of Matter

• Water can exist in all three states of matter: liquid, gas, and solid.
• Evaporation: the transition from the liquid state to the gas state
• As water heats up, hydrogen bonds break, and water molecules spread out away from each other.
• Condensation: the opposite reaction of evaporation
• As water vapor cools, molecules re-form hydrogen bonds, and gas turns to liquid.

Acids and Bases

• Molecules lose one or more hydrogen ions (H+) in an aqueous solution
• Acids: By donating H+ ions to water, acids increase the concentration of free H+ ions in solution, creating an acidic solution
• Bases: accept H+ ions from an aqueous solution
• By removing H+ ions, bases reduce the concentration of free H+ ions in solution, creating a basic solution.
• pH scale represents acidity vs. alkalinity where value above 7 indicates a basic solution and values below 7 indicate a basic solution

Opioid Receptors

• Dr. Bohn has researched how opioids affect the brain, with a focus on how to make painkillers safer and nonaddictive.
• Opioid receptors: membrane proteins that, when bound by opioids, sends signals into the cell
• These signals can result in pain relief, addictive euphoria, and changes in body physiology
• slight structural differences in compounds result from differences in one or more of their chemical bonds.

Explore carbon's bonding versatility, organic vs. inorganic compounds, and the role of 'Big Six' elements (C, H, N, O, P, S) in forming molecules essential for life. Examine electron sharing in methane, formaldehyde, and carbon dioxide. Understand valence shells and electron configurations within these key elements.