Exam 1 Review Flashcards
Lipids?
- nonpolar and polar regions (amphipathic)
- nonpolar regions interact
Proteins
55-75% weight of cells
- amino acid building blocks, linked by peptide bond
Carbohydrates
Monosaccharide building blocks
- form branches polymers
-hydrophilic
Nucleic acids
-nucleotide building blocks:
sugar
Base
Phosphate
- hydrophilic (polar)
- linked by phosphodiester bonds
- anionic
Water properties
Polar
H bonding between it gives it unique properties
H bonding is stronger than other dipole dipole bonding
Interaction strength
Covalent= 400 (kJ/ mol)
Ionic= 90
H bond= 20
Dipole-dipole= 9
London dispersion=
Enthalpy
Delta H: equivalent to total chemical energy (heat).
Favorable delta H is exothermic
Greater than 0= endothermic
Entropy
Delta S: disorder
Favorable Delta S is >0
Free energy
Delta G>0= non spontaneous (endergonic)
Delta G
Standard state use?
Standard states can be used to compare the energetic a between two reactions
Describe the relationship between H+, pH, and how buffers affect solution pH
H+ is the number of hydrogen ions in a solution, the - log of H+ (pH) is a measure of acidity.
pKA is the specific pH for each conjugate acid-base pair in which it is half deprotonated. (At equilibrium)
A buffer system is a system that resists changes in pH when H+ or OH- is added.
Each acid-base pair has a pH zone in which it is an effective buffer, this is 1 pH unit above or below the pKA.
A-/HA
A- = base
HA= acid
How to write protein sequences?
N terminus denotes the beginning and the Amino terminal residue
C terminus denotes the end and the carboxyl terminal residue
Conservative vs non-conservative mutations
Conservation refers to TYPE of amino acid (polar, nonpolar, etc)
Invariant= never changing
Ionizable amino acids
Tyrosine Cysteine Arginine Lysine Histidine Glutamic acid Aspartic acid
Phosphorylatable amino acids
Serine
Threonine
Tyrosine
Disulfide bond forming AA
Cysteine
Peptide?
Peptides are condensation products of amino acids
Less than or equal to 49 AA’s
Formed through a dehydration synthesis
Polypeptide?
Covalently linked amino acids
Proteins= polypeptides + coenzymes/ cofactors/ prosthetic groups/ etc
Peptide functions
Hormones and pheromones:
Neuropeptides
Antibiotics
Protection
UV maximal absorbance?
Tryptophan and tyrosine
Absorbance around 280
UV maximal absorbance?
Tryptophan and tyrosine
Absorbance around 280
