00:01
Hello students, in this question we are being given three monosaccharides which are sugars and we are being asked to tell us whether they are alpha or beta configuration, they have d or l configuration, they have pyranose or pyranose ring system.
00:25
So, coming to the first one whether it is alpha or beta isomer it is determined by the carbon number one, this is carbon number one.
00:36
If the oh group on the carbon number one is above then it is called as beta and if it is below then it's called an alpha.
00:51
So, if the oh group on carbon number first is above so this one is alpha isomer.
00:59
Now, coming to the second part which was asking whether it is d or l, d means dextrorotatory, l means levorotatory.
01:11
So, it is determined by the carbon number five here which is known as anomeric carbon and on this anomeric carbon if this group ch2oh group is above it is called the dextrorotatory.
01:32
If it is below then it is called levorotatory.
01:38
So, since it is above so it will be called as dextrorotatory.
01:44
So, it is alpha d.
01:46
Now, it is alpha d galacto which is already given in the question we were only supposed to tell whether this is alpha, beta or d or l.
02:03
So, alpha d galacto another thing we are supposed to tell whether this is a pyranose or furanose.
02:19
So, it is determined if the ring system contains five carbon then it is a furanose.
02:27
If the ring system ring contains six carbon then it is a pyranose.
02:32
Now, we calculate the number of carbon it contains one two three four five.
02:41
Here are five carbons in the ring sorry not carbons the ring must contain six atoms...