Chapter 2 Molecular Interactions Flashcards
Define an Atom
The smallest unit of matter is the element or ATOM
Atoms are the primary “building blocks”
What were the three primary components that make up an atom?
Protons, Neutrons and electrons
What is inside of the nucleus of an atom
Contains protons and neutrons.
The exception is hydrogen
Where are the electrons located?
Electrons occupy orbitals or shells outside the nucleus
What are the components that determine the nature of an atom?
Atomic mass: which is the sum of protons and neutrons in an atom
Atomic number: number of protons in an atom
What is an Isotope?
It’s a different atom of the same element. E.g. Carbon isotopes: 12C, 13C, and 14C
Isotopes have the same atomic number because the number of protons does not change. Isotopes differ in the number of NEUTRONS found in the nucleus.
How are Atoms Joined to others?
By three major types of bonds:
Covalent bonds
Ionic bonds
Hydrogen bonds
Van der Waals forces
Define Covalent bonds?
Arise when two atoms share an electron, this sharing of electron completes the outer shells of each and stabilizes the atoms
In non-polar covalent molecules, the atoms __________ __________ electrons?
In non-polar covalent molecules, the atoms EQUALLY SHARE electrons
E.g. Is methane
In polar covalent molecules, what type of sharing is taking place between electrons?
In polar covalent molecules, UNEQUAL sharing of electrons
E.g. Water
When electrons are shared unequally what happens between the atoms?
The stronger attraction for electrons develops a slightly negative charge (-)
The weaker atom with a weaker attraction for electrons develops a slightly positive charge
These are called polar molecules because they have positive and negative ends or poles?
Define Ionic Bonds?
Ionic bonds occur when valence electrons are transferred from on atom to another, forming charged ions
What are the two charged ions that are formed from transferring valence electrons?
Cation (+ charged)
Anion (- charged)
When molecules of opposite charges come close enough the charged ions attract. E.g. Na+ and Cl-
What is the easiest way to disrupt ionic bonds?
They are easily disrupted by water, as the ions interact with water molecules.
What type of bonds are Hydrogen bonds?
They are weak interactions between hydrogen and a nearby oxygen, or nitrogen or fluorine atom.
It’s a weak attractive force!
No electrons are gained, lost, or shared in a hydrogen bond
What Molecules are Associated with life called?
Molecules that contribute to life function are often called “Organic molecules”
What are organic molecules made of? Usually?
Usually made up of Carbon, hydrogen, and oxygen
What are the 4 major groups of organic molecules that are necessary for life function?
Carbohydrates
Lipids
Proteins
Nucleotides
What are carbohydrates primary functions?
Carbohydrates are often used as fuel sources
Carbohydrates can also combine with other macromolecules and thus serve a structural function
What are the 3 major carbohydrate groupings (based on structure)?
Monosaccharides (single sugar) e.g. Glucose, Galactose, Fructose
Dissacharides (two sugars combined) e.g. Lactose (Galactose+Glucose), Sucrose (Glucose+Fructose)
Polysaccharides (multiple sugars) e.g. Starches, glycogen
What are 4 different types of Lipids:
Triglycerides
Phospholipids
Cholesterol and its Derivatives
Eicosanoids