Bond & Polarity
This determines how strongly an atom pulls electrons.
What is electronegativity?
Water molecules stick to each other through this force.
What are hydrogen bonds?
This law states that energy cannot be created or destroyed, only converted.
What is the First Law of Thermodynamics?
Proteins are polymers made of these monomers.
what are amino acids?
A bond between atoms with very different electronegativities is this type.
What is a polar covalent bond?
Water is polar because oxygen is more ______ than hydrogen.
Electronegative.
This law states that the universe tends toward greater disorder.
What is the Second Law of Thermodynamics?
This reaction joins amino acids together by removing water.
What is dehydration synthesis?
Rank these from most polar to least polar:
O–H, N–H, C–H
O–H > N–H > C–H
Why does water have high surface tension?
Because of hydrogen bonding between water molecules (cohesion).
Entropy (S) measures this property of a system.
What is disorder or randomness?
This reaction breaks peptide bonds by adding water.
What is hydrolysis?
A molecule contains mostly C–H bonds and very few O or N atoms.
Predict its interaction with water.
It will be nonpolar and poorly soluble.
Why do nonpolar molecules cluster together in water?
Because water excludes them to preserve hydrogen bonding (hydrophobic effect).
If ΔG < 0, a reaction is this.
What is exergonic (thermodynamically spontaneous)?
Hydrophobic amino acids are usually found where in a folded protein, and why?
In the interior, because they avoid water.
If you add several O–H groups to a nonpolar molecule, what happens to polarity and solubility?
Both increase.
If you increase the length of a hydrocarbon chain, what happens to solubility in water?
It decreases.
Dehydration synthesis forms ordered macromolecules.
Does this increase or decrease entropy of the system?
Entropy of the system decreases (more order).
Water is involved in both protein folding and protein breakdown. Explain how.
Folding: hydrophobic effect pushes nonpolar residues inward.
Breakdown: hydrolysis uses water to break covalent peptide bonds.