Lab Quizzes

Question 1

What are monosaccharides?

Answer 1

The simplest form of sugar and the most basic units of carbohydrates. They cannot be hydrolyzed to form simpler sugars

Question 2

What are 3 examples of monosaccharides?

Answer 2

Glucose, Fructose, and Galactose

Question 3

What are polysaccharides?

Answer 3

Polysaccharides are long chains of monosaccharides linked by glycosidic bonds.

Question 4

What are 4 examples of polysaccharides?

Answer 4

There are storage polysaccharides such as starch and glycogen, and structural polysaccharides such as cellulose and chitin.

Question 5

What is the general formula for carbohydrates?

Answer 5

CnHnOn

Question 6

What are reducing sugars?

Answer 6

A reducing sugar is a chemical term for a sugar that acts as a reducing agent (as it has an aldehyde) and can donate electrons to another molecule. (It is a carbohydrate that is oxidized by a weak oxidizing agent (an oxidizing agent capable of oxidizing aldehydes but not alcohols, such as the Tollen’s reagent) in basic aqueous solution. The characteristic property of reducing sugars is that, in aqueous medium, they generate one or more compounds containing an aldehyde group)

Question 7

Is Lactose a reducing sugar and why?

Answer 7

Yes, because in order to be a reducing sugar, the sugar needs a free aldehyde or ketone group. Lactose has free groups and therefore is a reducing sugar.

Question 8

The biuret reagent reacts with protein to give which colour?

Answer 8

The normal color of biuret reagent is blue. The reagent turns violet in the presence of peptide bonds – the chemical bonds that hold amino acids together. The proteins detected must have at least three amino acids, which means that the protein must have at least two peptide bonds.

Question 9

Water shows high cohesion and surface tension and can absorb large amounts of heat because of large numbers of which type of bonds between water molecules?

Answer 9

Hydrogen bonds