Carbohydrates (2) Flashcards
Which of the following carbohydrates is associated with crustacean shells?
cellulose
chitin
glucose
glycogen
Chitin
Which of the following is true of the hydrolysis of carbohydrates?
- carbohydrates cannot be hydrolyzed
- hydrolysis of carbohydrates can only yield polyhydroxyaldehydes
- hydrolysis of carbohydrates can only yield polyhydroxyetenes
- hydrolysis of carbohydrates can yield polyhydroxyaldehydes and/or polyhydroxyketones
hydrolysis of carbohydrates can yield polyhydroxyaldehydes and/or polyhydroxyketones
How many chiral carbons are present in the open-chain chain (Fischer) form of galactose?
-3 -4 -5 -6
4
which of the following ours when a monosaccharide is converted to an amino sugar?
- an amino group replaces an aldehyde carbonyl
- amino group replaces a ketone carbonyl
- an amino group replaces a hydroxyl group
- any of the above, depends on the identity of the monosaccharide
an amino group replaces a hydroxyl group
The cyclic structures of monosaccharides are which of the following?
- acetals
- hemiacetals
- ethers
- esters
hemiacetals
When fructose adopts a cyclic (Haworth form), it will have a ___ structure.
- Pyranose
- furanose
- ketose
- hexose
furanose
The OH group attached to the ___ chiral carbon from the carbonyl group is used to determine D or L isomer
- closest
- middle
- farthest
- first
farthest
Which of the following is true of the spatial distribution of the hydroxyl groups of n-D-glucopyranose?
- they are all in axial positions
- they are all in equatorial positions
- the hydroxyl on C1, those on C2, C-3, and C3 are equatorial
- the hydroxyl on C-1 is equatorial, those on C2, C3 and C4 are axial
the hydroxyl on C1, those on C2, C-3, and C3 are equatorial
Which of the following reacts with sugars to form glycosides?
- alcohol
- amines
-hemiacetals - water
alcohol
Glycosides are example of which class of compounds?
- acetals
- hemiacetals
- esters
- ethers
ethers
Which of the following explains why glycosides do not undergo mutarotation?
- there is no longer an anomeric carbon
- there are no longer any stereocenters
- the ring carbon does not open to become rinh structure
- none of the above
the ring carbon does not open to become rinh structure
An alpha(1->4) glycosidic bond can be seen from the following
- lactose
- maltose
- sucrose
- all of the above
maltose
Which of the following determines blood type A in the ABO blood typing system?
- the presenve of only N-acetyl-D-galactosamine antigen
- the presence of only D-galactose antigen
- the presence of both N-acetyl-D-galactosamine antigen and D-galactose antigen
- the absence of both N-acetyl-D-galactosamine antigen and D-galactose antigen
the presence of only N-acetyl-D-galactosamine antigen
Which of the following is obtained as a result of the complete hydrolysis of starch?
- D-glucose
- maltose
- lactose
- sucrose
D-glucose
Which of the following is true of amylopectin?
- it consists of as many as 4000 D-glucose units linearly linked by ALPHA (1->4) glycosidic bonds.
- it consists of as many as 4000 D-glucose units linearly linked by BETA(1->4) glycosidic bonds.
- it consists of as many as 4000 D-glucose units linearly linked by ALPHA(1->4) glycosidic bonds. and there are branches every 24-30 units via ALPHA (1->6) glycosidic bonds
- it consists of as many as 4000 D-glucose units linearly linked by BETA(1->4) glycosidic bonds. and there are branches every 24-30 units via BETA(1->6) glycosidic bonds
it consists of as many as 4000 D-glucose units linearly linked by ALPHA(1->4) glycosidic bonds. and there are branches every 24-30 units via ALPHA (1->6) glycosidic bonds
