Quiz - Carbohydrates | Carbohydrates
What atoms are carbohydrates made of?
Carbon and hydrogen
Carbon and oxygen
Carbon, hydrogen and oxygen
Carbon, hydrogen, oxygen, nitrogen
A carbohydrate is a biomolecule consisting of carbon, hydrogen and oxygen atoms
What are monosaccharides?
Aldoses
Ketoses
Monomer of polysaccharides
All of the above
Monosaccharides, also called simple sugars, are the simplest form of sugar and the most basic units of carbohydrates: they are aldehydes (aldoses) or ketones (ketoses) that contain at least 2 additional hydroxy groups
Polysaccharides are polymers of monosaccharides
What is the most common configuration of sugars in nature?
In L-form
In D-form
In α anomer
All of the above
Sugars are classified as D when the highest-numbered stereocenter (= the one farthest from the carbonyl group) is R, L when it is S. Configuration D is the most common in nature
Which of the following synthesis conditions is used to oxidize sugars to monocarboxylic acid?
HNO3, H2O
HNO3, H2O, Δ
Br2, H2O
Na2Cr2O7, H2SO4, H2O
Oxidation to mono- or dicarboxylic acids:
What is the mechanism of etherification of sugars?
SN2
E2
Addition-elimination
Hemiacetal formation
Ag2O deprotonates each alcohols forming alkoxides RO- which reacts with CH3I in an SN2 reaction
What is the most common monomer of polysaccharides?
Glucose
Fructose
Cellulose
Amino acids
Nature is remarkably conservative in the construction of polysaccharides: the 3 most abundant natural polysaccharides (cellulose, starch and glycogen) are derived from the glucose