BIO 121 Exam 1 Glycosidic Bonds
process of translation
gene is transcribed to pre-mRNA premRNA is processed to mature mRNA exits nucleus translated on ribosomes
aglycone
group attached to carbohydrate that is not another saccharide
resonance in amide groups
has 3 resonance forms
ribosome
have 2 subunits are where the mRNA is translated contains rRNA and ribosomal proteins
# of amino acids
50-100 is a polypeptide over 100 is a protein
sites on ribosome
A site and P site A = aminoacyl binding site P = peptidyl binding site
difference between alpha and beta glycosidic bonds
based on relative stereochemistry of anomeric position alpha has axial orientation beta has equatorial orientation
metasable
bonds that will break in presence of water
glycoside hydrolases
break glycosidic bonds. act on either alpha or beta
polypeptide
chains of aa held by peptide bonds (backbone of PNA)
speed of folding
conformational folding is faster than cis trans isomerization
peptide bond/link
covalent bond between 2 molecules carboxyl reacts with amine group create an "amide" or amino acid
glycosidic bond
covalent bond that joins carbohydrate with other molecule (amino group or other nitrogen-containing group) from between hemiacetal group of saccharide and hydroxyl group of another compound
ethyl glucoside
ethanol and glucose with an alpha glycosidic bond
glucuornidation
joining substance to glucuronic acid to increase solubility
mRNA components
leader, reading frame, and trailer sequence
peptidyl prolyl isomerases
naturally occurring enzymes that catalyze cis and trans isomerization of X Pro peptide bonds
O-glycosidic bond
oxygen links glycoside to aglycone or sugar
C-glycosol
oxygen replaced by carbon. more resistant to hydrolysis
reactivity of peptide bond
peptide bond is unreactive react by attack of electronegative atom on carbonyl carbon, breaking double bond, and forming tetrahedral intermediate
isomers of amide group
planar because of partial double bond cis or trans isomer equal in energy trans form is in most peptide bonds dihedral is 0 for cis isomer and 180 for trans isomer
tRNA
recognize codons bring amino acids to ribosome encoded by tRNA genes all similar in shape and size have CCA at 3 prime end to which amino acid attaches have anticodon on other end
adenosine
sugar ribose and adenine bonded by N-glycosidic bond (bonded to Nitrogen) glycosylamines
S-glycosidic bond
thioglycosides oxygen in glycosidic bond is replaced with sulfur
sugar nucleotides
when monosaccharides are joined by a glycosidic bond to the phosphate group of a nucleotide to be activated