Rowland Flashcards
Which macromolecules are soluble in water?
DNA, RNA always.
Carbohydrates and protein: yes/sometimes
Explain Hydrogen Bonding
Hydrogen bonds are formed between a proton (H atom) covalently bonded to an electronegative atom and a second electronegative atom that serves as the hydrogen bond acceptor.
What is a property of a biomolecule?
- have a restricted set of conditions at which they can work (temp, pH)
- altered by our metabolism (we can harvest energy to do this, or we harvest energy from them as we alter them)
- source components of biomolecules from the environment and/or we can produce our self.
What difference in bond polarity is need for a pond to be non-polar, polar covalent or ionic?
non-polar: 0-0.5
polar covalent: 0.5-1.7
ionic: >1.7
What is a covalent bond?
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms; usually between to non-metals.
What happens when two atoms of unequal
electronegativity are covalently bonded to one another?
The atom that is more electronegative will draw the electrons closer to itself, creating a partial negative dipole at that end and a partial positive dipole at the atom with less electronegativity.
What are the major determinants of solubility in water?
Charge, polarity, and the ability to form
hydrogen bonds
What are the backbones of biomolecules made of and how are they bonded?
biomolecules have backbones that are
covalently bonded, and they are carbon-based backbones
Draw the structure of an amino acid
Amino group Carboxy Group R-group Hydrogen carbon center
What is the difference between intra and inter?
Intra: within one molecule
Inter: between two different molecules
When we cook an egg the proteins denature but do not degrade. Why?
Because the weak forces are broken but not the covalent bonds
Explain Van der Waals contact distance
The optimal distance between two atoms for the structural stability
The distance at which electrons interact optimally
How does water operate as a solvent?
Water is heavily hydrogen bonded to itself. The water molecules make and break these bonds repeatedly, with a half-life for each bond of about 10 psec. This is a highly thermodynamically favorable situation because it is chaotic, with many favorable bonds. Water soluble molecules make multiple favorable hydrogen bonds with water due to their own electronegative atoms.
What bond holds base pairs together?
Hydrogen bonds
What type of bond drives the secondary structure formation in proteins and carbohydrates?
Hydrogen bonds
What is the hydrophobic effect?
The hydrophobic effect is the observed tendency of nonpolar substances to cluster in aqueous solution and exclude water molecules.
What does the disparity in bond strength mean for biology?
- Some bonds are much stronger than others
- Some bonds need to stay intact under stress
- Some bonds are made to be broken
- Some interactions are reversible
- Some states are more energetically favorable than others.