Midterm #1 Flashcards
how many amino acids are found in the genetic code
20
how many amino acids have ionizable chains
7
what is the structure of an amino acid
H
|
+NH3-Ca-COOH
|
R
which amino acids are exceptions to amino acid structure
glycine (R-group is an H)
proline (R group is bound to alpha amino group)
how do you name the carbon atoms on amino acids
alpha, beta, gamma, delta, episilon
how are amino acids grouped
non polar, polar, electrically charged side chains
how does the symmetry of polar vs. non polar molecules differ
polar compounds –> asymmetrical
non polar compounds –> symmetrical
which amino acids have non polar side chains
- glycine (Gly)
- alamine (Ala)
- valine (Val)
- leucine (Leu)
- isoleucine (Ile)
- methionine (Met)
- phenylalanine (Phe)
- tryptophan (Trp)
- proline (Pro)
what do all amino acids with non polar side chains have in common
possess hydrocarbons –> CH4
what does aliphatic mean
compounds that have open chains (ex. -CH2CH2CH3) that are acyclic
which amino acids have polar side chains
- serine (Ser)
- threonine (Thr)
- cystine (Cys)
- tyrosine (Tyr)
- asparagine (Asn)
- glutamine (Gln)
which amino acids have electrically charged side chains
- aspartate (Asp)
- glutamate (Glu)
- lysine (Lys)
- arginine (Arg)
- histidine (His)
whats the protonated form of aspartate
aspartic acid
whats the protonated form of glutamate
glutamic acid
what is the structure of amino acid in a vacuum
H
|
H2N-C-COOH
|
R
what is the structure of amino acid in biological conditions (water)
H
|
H3N-C-COO
|
R
rank the solubility of side chains
non polar are least soluble, then polar, and electrically charged are the most soluble
what is a delineation for typical solubility rules
molecule factors (ex. size)
why might one molecule be more soluble in water than another
polar molecules make favorable interactions with water - ex. ion dipole and hydrogen bonds
explain an ion-dipole
- ions make ion-dipole interactions in water
- ion dipole occurs between charged atom / molecule and a polar molecule
what is a hydration shell
water that surrounds a charged atom
describe a hydrogen bond
- H atom covalently bonded to N, O, or F (hydrogen donor) attracted to another EN atom (hydrogen acceptor)
what is the hydrophobic effect
occurs when non-polar molecules are excluded by water in order to maximize the number of hydrogen bonds it can make with itself
what is a diprotic amino acid
an amino acid with two places that can donate a proton