Biochemistry Flashcards
Define matter
Anything that takes up space and has mass
What is matter made up of ?
Atoms- smallest unit of matter- protons and electrons
Define Ionic bonds
Complete transfer of electrons from atom to another (exist between ions)
Define covalent bonds
Electrons shared between atoms with similar electronegativities- single, double, or triple bonds
Non-polar bonds?
Equal sharing of electrons (highly similar electronegativity)
Polar Bonds?
unequal sharing of electrons, forms a dipole
Hydrogen Bond?
Weak bond between molecules
Conditions-
- H bonded to F,O,N (highly electronegative
- intramolecular or intermolecular
Intramolecular
Within molecule
Intermolecular
Between molecules
Define Van der Waals Interactions
Weak, temporary attraction
between atoms or molecules in close proximity.
Occurs
due to the transient, uneven distribution of electrons in a
molecule at any given time.
Weak attraction individually,
but can add up to a powerful force.
think movement like planets.
Water- polar or nonpolar?
Highly Polar molecule capable of hydrogen bonding
Why is water an excellent solvent?
dipoles of H2O can interact with opposite charges in polar or ionic molecules- surrounding these charged molecules with a hydration shell (like-dissolves- like)
Define High Heat Capacity of Water
amount of heat needed to raise the temp of water (water is very temp. stable)
Density of water, explain (ice example)
Water is denser as a liquid vs a solid
Explain Cohesion
Attraction between like molecules (H2O has high cohesion)
produces a high surface tension
Explain Adhesion
Attraction between unlike substances
High EN Atom?
atoms are kept close to the nucleus
Low EN Atom?
In low electronegative bonds the electrons are further apart
Bond in DNA?
Hydrogen Bonds
An atom with a high electronegativity would have electrons that are _____.
Held close to the nucleus
the difference between intermolecular and intramolecular forces?
Intermolecular forces occur between molecules, intramolecular forces occur within a molecule
Van der Waals interactions are the weakest type of bonds, True or False?
true
best describes an ionic bond?
Complete transfer of electrons from one atom to another
Water
Excellent solvent, chemical reactions take place in water
