2Rings And Variants Flashcards
Ketone + alcohol
Hemiketal
Aldehyde + alcohol
Hemiacetal
Which two groups react to form a hemiacetal on the glucose molecule?
The alcohol on carbon #5 and the aldehyde of carbon#1 react since they are closest to rah other and form the ring.
Alpha Hemiactetal is due to:
The OH group pointing down on carbon #1
Beta Hemiacetal is due to:
The OH group is pointing up
What form is 99% of glucose in?
Ring structure alpha or beta
Mostly the beta conformation
Which of the following is an anomeric pair?
Differs only in configuration at hemiacetal or hemiketal carbon
Alpha-D-glucose and Beta-D- glucose
Glucose is the oxidizing sugar that is reduced into:
D-Glucitol
Glucose turns into Glucitol by:
Reducing an aldehyde into an alcohol on c#1
Glucose turns into gluconate by:
Oxidizing the aldehyde group to Carboxylic acid…this would be oxidized sugar
Sugars that can undergo oxidation are called:
Reducing sugars
Diabetes test: copper turned brick red with urine…copper was reduced because the sugar became oxidized
Sugars with aldehyde groups are…
Reducing sugars
Oxidizing sugar
Oxidizes other substances and gains electrons so the oxidation state will decrease.
The oxidize sugar will gain oxygen and release hydrogen.
Reducing sugar
The aldehyde functional group allows the sugar to act as a reducing agent. You aldehyde can be oxidized via a redox reaction in which another compound is reduced. Thus, a reducing sugars one that reduces certain chemicals.
The reducing sugar will gain hydrogen and lose oxygen
Glucose turns into gluconate
Fructose is a _____ sugar
Fructose can be a reducing sugar because it can isomerize to glucose or mannose, this happens very slowly at room or body temperature but it is very rapid when heated in the test tube.
Can rearrange to be a reducing sugar.
D-glucose is called a reducing sugar because it undergoes an oxidation – reduction reaction at the anomeric carbon. What are the products of this reaction is:
D-glauconate
D- Ribose structure
H O
\ //
H- C - OH
l
H- C -OH
l
H- C-OH
l
CH2OHDeoxy-D- Ribose
*deoxy
Removed OH on C#2
H O
\ //
C
l
H- C- H
l
H- C- OH
l
H- C- OH
l
CH2OH
Oxidized sugars
Beta-D- Glucoronate
Carboxylic acid on carbon #6
D-Gluconate
Oxidize carbon #1 and Carboxylic acid where aldehyde used to be and can form ring
D-Glucono-S- lactone
Ring formed from Carboxylic acid on carbon #1
Glucuronates are very useful in helping to excrete:
Less than water soluble molecules
They increase water solubility of target molecules to facilitate excretion from the body.
Ex: Bilirubin- a break down product from heme and can conjugate to Glucoronate to increase water solubility
Direct Bilirubin
It is water-soluble in a conjugated form that is attached to two glucuronates to the Bilirubin molecule
Indirect Bilirubin
It is the non-conjugated form that is usually found bound to albumin in the blood
Oxidize sugars are also known as
Acidic sugars
Modified acidic sugar:
NANA
N-Acetylneuramibic acid
Amino sugars:
Has nitrogens instead of oxygens on the sugar rings.
Ex: Beta-D- Galactosamine
Has NH2 in position #2
and Beta-D- Mannosamine
Has mannose in N #2
Common sugar abbreviations
Fructose. Fru Galactose. Gal Glucose Glc mannose man ribose. Rib
Glucuronic acid. GlcA Galactosamine. GalN Glucosamine. GlcN N-acetyl galactose amine. GalNAc N-acetyl glucosamine GlcNAc
Which of the following monosaccharides is not a carboxylic acid?
Glucose
Which of the following is anomeric pair?
Same structure but OH group flipped to opposite sides
Alpha-D- glucose and Beta-D-glucose
Which of the following sugars contain a Ketone?
Fructose
Which seven of the following sugars are monosaccharides?
Galactose Ribose Glyceraldehyde Glucuronate Mannose Glucose Fructose
Which of the following sugars contains only glucose?
Maltose
Which of the following sugars would test negative to the reducing sugar test?
Sucrose
What is the configuration of D – glyceraldehyde?
R
Which of the following is a five carbon sugar?
Ribose
Which of the following is an epimer of glucose?
Mannose
Fructose contains which of the following functional groups?
Keytone and alcohol
If a urine sample of a diabetic patient has copper (II) nitrate added to it, is heated and as a result a brick red precipitate forms, what most likely happened?
Glucose is oxidized
The reduced form of glucose is named?
Sorbitol
When glucose forms a ring, what happened?
One of the alcohol groups reacted with the aldehyde
Which of the following is contains glucose (Alpha 1–4) bond?
Maltose
Amylose
The enzyme lactase, found in our intestine, breaks which type of bond?
Gal( beta1-4)
Which of the following bond is found in glycogen?
Glu(alpha1-6)
Glu(alpha 1-4)
What is another biochemical name for repeating disaccharide?
Glycan
