Lecture 1/13/25 Flashcards
What macromolecules are used by living cells?
Proteins, nucleic acids, carbohydrates, and lipids.
What does a Lewis dot structure help us predict?
It predicts bonding behavior, electron distribution, and molecular shape.
What is a Valence Shell?
The outermost electron shell that determines an atom’s bonding properties.
What is an Ion?
An atom that has gained or lost electrons, becoming charged.
Which two columns of the Periodic Table donate electrons to become Ions?
Groups 1 and 2 (alkali and alkaline earth metals).
Which two columns receive electrons?
Groups 16 and 17 (chalcogens and halogens).
What is the difference between a Covalent and an Ionic bond?
Covalent bonds share electrons; ionic bonds transfer electrons creating charged ions.
How many bonds do carbon, oxygen, hydrogen, and nitrogen like to form?
Carbon forms 4, Oxygen 2, Hydrogen 1, and Nitrogen 3 bonds.
What are double and triple bonds?
Double bonds share 4 electrons; triple bonds share 6 electrons, reducing flexibility.
What is a dipole?
A molecule with partial positive and negative charges due to unequal electron sharing.
What is a Hydrogen Bond?
A weak attraction between a partially positive hydrogen and an electronegative atom.
Can polar molecules form hydrogen bonds with nonpolar molecules?
No, hydrogen bonds only form between polar molecules.
What is the difference between hydrophilic and hydrophobic?
Hydrophilic molecules interact with water; hydrophobic molecules repel water.
What are the four main atom-atom interactions?
van der Waals, Hydrogen bonds, Ionic bonds, Covalent bonds (weakest to strongest).
What are van der Waals interactions?
Weak, transient attractions due to fluctuating electron densities in nearby molecules.
What makes van der Waals interactions different?
They are weaker and more transient than hydrogen, ionic, or covalent bonds.
