BCHM 4611 Exam 3 | Questions with 100% Verified
Answers | Latest Update
Question:
Draw D-Glucose Fischer projection
Answer:
Question:
Draw the ring structure of D-glucose
Answer:
Question:
What is the anomeric carbon?
Answer:
THe most oxidized carbon in a monosaccharide. C 1 in aldoses, C-2 in ketoses
Question:
What is a ketohexose?
Answer:
sugar with Ketone on 2nd carbon
-"anomeric carbon" has two alcohols attached
(i.e fructose)
,Question:
What is an aldose?
Answer:
a monosaccharide with an aldehyde group
Question:
How do you number the carbons in a Fischer projection?
Answer:
You assign the lowest possible number to to the anomeric carbon.
Question:
What are epimers?
Answer:
Diastereomers that differ in the configuration of ONE carbon.
Question:
What is the C-4 epimer of glucose?
Answer:
galactose
Question:
What is a stereocenter?
, Answer:
an atom at which the interchange of two groups produces a stereoisomer
Question:
How can you differentiate between L and D configurations?
Answer:
If the last stereocenter of the Fischer projection has an OH group that goes to the left it's an L
configuration and if the OH group goes to the right is the D configuration.
Question:
How can you tell if a sugar is in the D or L configuration?
Answer:
If the last carbon goes up the sugar is a D conformation. If it goes down then it is an L conformation.
Question:
What does Cu2+ turning red when put in a sugar solution mean about the sugar?
Answer:
It means the Cu2+ is reduced to Cu+ which indicates the presence of aldehydes and
alpha-hydroozyketones in the solution.
Question:
What is a reducing sugar?
Answer:
A sugar that reacts with an oxidizing agent
Question:
How is a glycosidic bond formed?
Answer:
A glycosidic bond forms when the anomeric carbon is joined to another group. (this makes it
non-reducing)
Question:
What can you tell about a sugar that has an anomeric carbon with a free hydroxyl in the ring form?
Answer:
, It will have an aldehyde or a ketone in the open chain form and that it is a reducing sugar.
Question:
What are five ways in which a monosaccharide can be chemically modified?
Answer:
- Phosphorylation
- Aminated
- Oxidized
- reduced
- Covalently linked
Question:
How can you tell if a ring sugar is in a Beta configuration?
Answer:
The enomeric carbon (carbon 1) has an OH group in the upward direction.
Question:
How can you tell if a sugar is in the alpha configuation?
Answer:
The enomeric carbon (carbon 1) has an OH group in the downward direction.
Question:
What is a starch?
Answer:
storage form of glucose in plants
Question:
What is amylose?
Answer:
A long unbranched chain of alpha glucose. Uses alpha 1-4 linkages.
Answers | Latest Update
Question:
Draw D-Glucose Fischer projection
Answer:
Question:
Draw the ring structure of D-glucose
Answer:
Question:
What is the anomeric carbon?
Answer:
THe most oxidized carbon in a monosaccharide. C 1 in aldoses, C-2 in ketoses
Question:
What is a ketohexose?
Answer:
sugar with Ketone on 2nd carbon
-"anomeric carbon" has two alcohols attached
(i.e fructose)
,Question:
What is an aldose?
Answer:
a monosaccharide with an aldehyde group
Question:
How do you number the carbons in a Fischer projection?
Answer:
You assign the lowest possible number to to the anomeric carbon.
Question:
What are epimers?
Answer:
Diastereomers that differ in the configuration of ONE carbon.
Question:
What is the C-4 epimer of glucose?
Answer:
galactose
Question:
What is a stereocenter?
, Answer:
an atom at which the interchange of two groups produces a stereoisomer
Question:
How can you differentiate between L and D configurations?
Answer:
If the last stereocenter of the Fischer projection has an OH group that goes to the left it's an L
configuration and if the OH group goes to the right is the D configuration.
Question:
How can you tell if a sugar is in the D or L configuration?
Answer:
If the last carbon goes up the sugar is a D conformation. If it goes down then it is an L conformation.
Question:
What does Cu2+ turning red when put in a sugar solution mean about the sugar?
Answer:
It means the Cu2+ is reduced to Cu+ which indicates the presence of aldehydes and
alpha-hydroozyketones in the solution.
Question:
What is a reducing sugar?
Answer:
A sugar that reacts with an oxidizing agent
Question:
How is a glycosidic bond formed?
Answer:
A glycosidic bond forms when the anomeric carbon is joined to another group. (this makes it
non-reducing)
Question:
What can you tell about a sugar that has an anomeric carbon with a free hydroxyl in the ring form?
Answer:
, It will have an aldehyde or a ketone in the open chain form and that it is a reducing sugar.
Question:
What are five ways in which a monosaccharide can be chemically modified?
Answer:
- Phosphorylation
- Aminated
- Oxidized
- reduced
- Covalently linked
Question:
How can you tell if a ring sugar is in a Beta configuration?
Answer:
The enomeric carbon (carbon 1) has an OH group in the upward direction.
Question:
How can you tell if a sugar is in the alpha configuation?
Answer:
The enomeric carbon (carbon 1) has an OH group in the downward direction.
Question:
What is a starch?
Answer:
storage form of glucose in plants
Question:
What is amylose?
Answer:
A long unbranched chain of alpha glucose. Uses alpha 1-4 linkages.
