The R-S Convention 14) Either the letter R (rectus, or right) or S (sinister, or left) is used to designate the configuration at a stereogenic center. The four atoms or groups attached to the stereogenic center are arranged in a priority order according to atomic number: the higher the atomic number, the higher the priority (see Cahn-Ingold-Prelog rules for assigning priorities). If two atoms have the same atomic number, we move to the next atoms out from the stereogenic center, or even further, until we observe a difference in atomic number. We then view the molecule from the side opposite the group with the lowest priority. If the remaining three groups in order from highest to lowest priority form a clockwise array, the configuration is R; if counterclockwise, the configuration is S. a)Construct a model of 2-chlorobutane. Which carbon in the chain is a stereogenic center? b)What are the four groups attached to this stereogenic center? c)Which group has the highest priority? d)Which group has the lowest priority? e)Set the model on the lab bench so that it can be viewed from the side opposite the hydrogen, which is the lowest priority group attached to the stereogenic center. f)Do the three remaining groups form a clockwise or counterclockwise array? g)What configuration does your model have, R or S? h)Interchange any two groups attached to the stereogenic center. What configuration, R or S, does the model have now? Note to change configuration, we must disconnect and remake bonds, whereas we can change conformation by rotation of groups around single bonds.
Catalysis and Enzymatic Reactions
Catalysis is the kind of chemical reaction in which the rate (speed) of a reaction is enhanced by the catalyst which is not consumed during the process of reaction and afterward it is removed when the catalyst is not used to make up the impurity in the product. The enzymatic reaction is the reaction that is catalyzed via enzymes.
Lock And Key Model
The lock-and-key model is used to describe the catalytic enzyme activity, based on the interaction between enzyme and substrate. This model considers the lock as an enzyme and the key as a substrate to explain this model. The concept of how a unique distinct key only can have the access to open a particular lock resembles how the specific substrate can only fit into the particular active site of the enzyme. This is significant in understanding the intermolecular interaction between proteins and plays a vital role in drug interaction.
The R-S Convention
14) Either the letter R (rectus, or right) or S (sinister, or left) is used to designate the configuration at a stereogenic center. The four atoms or groups attached to the stereogenic center are arranged in a priority order according to
a)Construct a model of 2-chlorobutane. Which carbon in the chain is a stereogenic center?
b)What are the four groups attached to this stereogenic center?
c)Which group has the highest priority?
d)Which group has the lowest priority?
e)Set the model on the lab bench so that it can be viewed from the side opposite the hydrogen, which is the lowest priority group attached to the stereogenic center.
f)Do the three remaining groups form a clockwise or counterclockwise array?
g)What configuration does your model have, R or S?
h)Interchange any two groups attached to the stereogenic center. What configuration, R or S, does the model have now?
Note to change configuration, we must disconnect and remake bonds, whereas we can change conformation by rotation of groups around single bonds.
Trending now
This is a popular solution!
Step by step
Solved in 4 steps with 3 images
