Biochemistry Flashcards
What is matter?
Anything that has mass and takes up space
What is an atom?
The smallest unit of matter and is the basic building block of everything on Earth
What is matter made up of?
Atoms
What is found in atoms?
Subatomic particles (neutrons. protons, and electrons)
What is an element?
Made entirely of one type of atom
What is a molecule?
A group of two or more atoms held together by chemical bonds
What are chemical bonds?
Electron interactions between atoms (ionic, covalent, and hydrogen bonds)
What determines the type of bond formed between atoms?
Their difference in electronegativity
What is electronegativity?
The ability of an atom to attract electrons
What does it mean to be highly electronegative?
Electrons are kept close to the nucleus (pulls electrons more tightly to itself)
What does it mean to have a low electronegativity?
Electrons held further away from its nucelus
What is an ionic bond?
There is a complete transfer of electrons from one atom to another. A bond forms from a difference in charge between atoms
Which atom pulls electrons away from the other atom in an ionic bond?
The more electronegative atom pulls an electron away from the less electronegative atom
What is a covalent bond?
Atoms with similar ENs share electrons (can be nonpolar or polar sharing of electrons). Bonds can be single, double, or triple
What is a nonpolar covalent bond?
Equal sharing of electrons (no one atom has a greater pull). Forms between atoms with identical (or nearly identical) ENs
What is a polar covalent bond?
Unequal sharing of electrons (there is a difference in charge), which forms a dipole (electrons closer to the more EN atom)
What is a hydrogen bond?
A weak bond that forms between a hydrogen atom that is (1) covalently bonded to a highly electronegative atom and (2) is also attracted to a negative charge on another highly EN molecule. Can be intramolecular or intermolecular
What is an intramolecular hydrogen bond?
Hydrogen bond within a molecule
What is an intermolecular hydrogen bond?
Hydrogen bond between separate molecules
What are Van der Waals interactions?
Weak (and temporary) attractions between any atoms or molecules in close proximity
How do Van der Waals interactions form?
Electrons are always moving around the center of the atom, and so their charge distributions are always changing (changing areas of positive and negative charge). This difference in charge between molecules leads to a weak attractive force
What makes a strong Van der Waal interaction?
Many interactions add up to a powerful force
