I am so grateful you did this video. I've had a hard time with this in college and while studying for the MCAT. I now know and understand sugar structures. Thank you so much!
That's true! I have a whole series of chemistry basics on deck, including solubility foundations. I also cover the solubility and acid-base chemistry in depth in my course as they are essential MCAT topics to know for test day!
If a sugar molecule converts from an alpha sugar to a beta sugar (mutarotation you were talking about), will just C1 change orientation, or will the whole molecule invert? Thank you!!!
Great question! It will be just C1 - the rest of the molecule will stay as is. So if you convert from a-D-glucose to b-D-glucose, the orientation around C2 - C6 will all stay the same! HOWEVER! If you convert from D-glucose to L-glucose, that is a full enantiomer isomerization, which means all chiral centers will be flipped.
Can you explain why sucrose is still a 1-4 glycosidic bond instead of 1-5 or 1-2 ? Does the numbering of the fructose carbons change once it loses its free -OH group or am I just numbering wrong ? Also is sucrose neither alpha or beta since it only has the one anomeric carbon? Your videos have been the most helpful thing ever thank you SO much !!!!!!
Such a good question - sucrose is our funky dude and so breaks all the rules, and that was an error in my description in the video! Technically, sucrose as table sugar (which is what we would typically see) is a funky alpha-beta 1-2 bond, where both anomeric carbons are involved in the bond. This is why sucrose is a non-reducing sugar - we don't have an anomeric oxygen to reduce. The reason this gets tricky in drawings is that when sucrose is formed, fructose essentially does a "180" from how we normally draw it, with carbon 2 facing right. That's why it's easy to view it as a 1-4 bond, since we don't usually visualize our sugars "flipping" around. This is on the border of out-of-scope for the MCAT; they tend to focus on maltose and glycogen bonds since that's most directly related to metabolism, and they'll usually test sucrose as a non-reducing sugar. However, this was a great point to clarify, thank you so much for the question! Here's also a good reference sheet for the sugars and dissaccharides: basicmedicalkey.com/carbohydrates-3/
This is actually a cool clinical application! There's an enzyme, beta-galactosidase (aka lactase), that specifically breaks the beta bonds in lactose. Cellulose is a huge polymer that requires cellulase, not something that has evolved in most mammals. But lactose is in mammalian milk, so the theory is that we have evolved beta-galactosidase production while early in life, and that the levels drop off as we get older. This is the major reason for lactose intolerance - not enough lactase to break down lactose!
I am so grateful you did this video. I've had a hard time with this in college and while studying for the MCAT. I now know and understand sugar structures. Thank you so much!
That's amazing to hear! I'm so glad you're getting it now. And good luck on the rest of your prep!
Wow! Please make more. Packed with relevant info!!
Making more as we speak!
this was an amazing and super comprehensive video, amazing work.
Thank you so much! I hope it helped in your studying!
Thank you so much!! My last MCAT was heavily tested on Carbohydrates
Glad you liked it! These structures do tend to be a high priority MCAT topic
You’re the best
Thank you!
what a FANTASTIC video! Clear and concise with examples!
So glad you found it useful!
Fantastic video! Thank you so much! This channel has been a lifesaver!
So happy to hear it's helping!
I have been binge watching your videos and they are so easy to understand and really helped me, thank you!!
I'm so happy to hear that they're helpful! You're welcome!
This was such an amazing video! thank you so much!
You're welcome! So glad you found it helpful
This was SO HELPFUL. Thank you so so much
You're welcome! So glad it was useful!
Thank u so much! Super helpful.
So glad to hear that! You're welcome!
Thank you.
You're welcome!
@@bremmethod Any concepts you went over on your channel have been fixated on my memory and understanding. Your teaching is exceptional.
your videos are great, have you considered making one on solubility. It seems to be tested a lot in the chem phys section
That's true! I have a whole series of chemistry basics on deck, including solubility foundations. I also cover the solubility and acid-base chemistry in depth in my course as they are essential MCAT topics to know for test day!
One of the best channels I found while studying
Thank you!
You are a fantastic teacher!!
Thank you so much! It means so much to hear that
Excellent video
Glad you liked it!
great video!
Thank you!
You're amazing.
Thank you! So are you :)
fr god sent
Glad I could help!
If a sugar molecule converts from an alpha sugar to a beta sugar (mutarotation you were talking about), will just C1 change orientation, or will the whole molecule invert? Thank you!!!
Great question! It will be just C1 - the rest of the molecule will stay as is. So if you convert from a-D-glucose to b-D-glucose, the orientation around C2 - C6 will all stay the same!
HOWEVER! If you convert from D-glucose to L-glucose, that is a full enantiomer isomerization, which means all chiral centers will be flipped.
Can you explain why sucrose is still a 1-4 glycosidic bond instead of 1-5 or 1-2 ? Does the numbering of the fructose carbons change once it loses its free -OH group or am I just numbering wrong ? Also is sucrose neither alpha or beta since it only has the one anomeric carbon?
Your videos have been the most helpful thing ever thank you SO much !!!!!!
also how do we breakdown the beta bonds in lactose but we cant in cellulose? Thank you :)
Such a good question - sucrose is our funky dude and so breaks all the rules, and that was an error in my description in the video!
Technically, sucrose as table sugar (which is what we would typically see) is a funky alpha-beta 1-2 bond, where both anomeric carbons are involved in the bond. This is why sucrose is a non-reducing sugar - we don't have an anomeric oxygen to reduce.
The reason this gets tricky in drawings is that when sucrose is formed, fructose essentially does a "180" from how we normally draw it, with carbon 2 facing right. That's why it's easy to view it as a 1-4 bond, since we don't usually visualize our sugars "flipping" around.
This is on the border of out-of-scope for the MCAT; they tend to focus on maltose and glycogen bonds since that's most directly related to metabolism, and they'll usually test sucrose as a non-reducing sugar. However, this was a great point to clarify, thank you so much for the question!
Here's also a good reference sheet for the sugars and dissaccharides: basicmedicalkey.com/carbohydrates-3/
This is actually a cool clinical application! There's an enzyme, beta-galactosidase (aka lactase), that specifically breaks the beta bonds in lactose. Cellulose is a huge polymer that requires cellulase, not something that has evolved in most mammals. But lactose is in mammalian milk, so the theory is that we have evolved beta-galactosidase production while early in life, and that the levels drop off as we get older. This is the major reason for lactose intolerance - not enough lactase to break down lactose!