BIOMOLECULES

Question 1

Common examples of carbohydrates

Answer 1

cane sugar , starch , Glucose

Question 2

What is the general formula of carbohydrates?

Answer 2

The general formula of carbohydrates is Cₓ(H₂O)ᵧ.

Question 3

Why were carbohydrates originally called “hydrates of carbon”?

Answer 3

They were called “hydrates of carbon” because their general formula

Question 4

Give an example of a carbohydrate that fits the general formula Cₓ(H₂O)ᵧ.

Answer 4

Glucose (C₆H₁₂O₆)

Question 5

Give an example of a compound that fits the general formula Cₓ(H₂O)ᵧ but is not a carbohydrate.

Answer 5

Acetic acid (CH₃COOH)

Question 6

What is rhamnose

Answer 6

and why is it an exception to the general carbohydrate formula?

Question 7

How are carbohydrates chemically defined?

Answer 7

Carbohydrates are defined as optically active polyhydroxy aldehydes or ketones or compounds that produce such units on hydrolysis.

Question 8

What are some carbohydrates that are sweet in taste called?

Answer 8

Carbohydrates that are sweet in taste are called sugars.

Question 9

What is the common sugar used in home sand what is the sugar present in milk called?

Question 10

What is another name for carbohydrates?

Answer 10

Carbohydrates are also called saccharides.

Question 11

carbohydrates as classified on the basis of

Answer 11

hydrolysis

Question 12

carbohydrates divided into 3

Answer 12

Monosaccharides , Oligosacchrides , Polysacchrides

Question 13

What are monosaccharides?

Answer 13

Monosaccharides are carbohydrates that cannot be hydrolyzed further into simpler units of polyhydroxy aldehydes or ketones. Examples: Glucose, Fructose, Ribose.

Question 14

How many naturally occurring monosaccharides are known?

Answer 14

About 20 monosaccharides are known to occur in nature.

Question 15

Give examples of common monosaccharides.

Answer 15

Glucose, Fructose, Ribose.

Question 16

What are oligosaccharides?

Answer 16

Oligosaccharides are carbohydrates that yield two to ten monosaccharide units upon hydrolysis.

Question 17

How are oligosaccharides classified?

Answer 17

They are classified based on the number of monosaccharide units released upon hydrolysis, such as disaccharides, trisaccharides, and tetrasaccharides.

Question 18

What are the most common oligosaccharides?

Answer 18

Disaccharides are the most common oligosaccharides.

Question 19

What monosaccharides are obtained from the hydrolysis of sucrose?

Answer 19

Hydrolysis of sucrose yields one molecule of glucose and one molecule of fructose.

Question 20

What monosaccharides are obtained from the hydrolysis of maltose?

Answer 20

Hydrolysis of maltose yields two molecules of glucose.

Question 21

What are polysaccharides?

Answer 21

Polysaccharides are carbohydrates that yield a large number of monosaccharide units upon hydrolysis.

Question 22

Give examples of polysaccharides.

Answer 22

Starch, Cellulose, Glycogen, Gums.

Question 23

Why are polysaccharides called non-sugars?

Answer 23

Polysaccharides are not sweet in taste, so they are called non-sugars.

Question 24

What are reducing sugars?

Answer 24

Reducing sugars are carbohydrates that can reduce Fehling’s solution and Tollens’ reagent.

Question 25

Are all monosaccharides reducing sugars?

Answer 25

Yes, all monosaccharides (both aldoses and ketoses) are reducing sugars.

Question 26

How are monosaccharides classified based on their functional group?

Answer 26

Monosaccharides with an aldehyde group are called aldoses, while those with a keto group are called ketoses.

Question 27

How does the number of carbon atoms affect the naming of monosaccharides?

Answer 27

The number of carbon atoms is included in the name, such as triose (3C), tetrose (4C), pentose (5C), hexose (6C), and heptose (7C).

Question 28

What is an aldotriose?

Answer 28

An aldotriose is a three-carbon monosaccharide with an aldehyde group.

Question 29

What is a ketotriose?

Answer 29

A ketotriose is a three-carbon monosaccharide with a keto group.

Question 30

Give an example of an aldohexose.

Answer 30

Glucose is an example of an aldohexose.

Question 31

Give an example of a ketohexose.

Answer 31

Fructose is an example of a ketohexose.

Question 32

Glucose occurs as

Answer 32

freely and in combined form

Question 33

glucose present in

Answer 33

Fruits, Grapes, Honey

Question 34

What happens when sucrose is boiled with dilute HCl or H₂SO₄ in an alcoholic solution?

Answer 34

Sucrose undergoes hydrolysis, yielding equal amounts of glucose and fructose.

Question 35

Write the chemical equation for the hydrolysis of sucrose.

Answer 35

C₁₂H₂₂O₁₁ + H₂O → C₆H₁₂O₆ (Glucose) + C₆H₁₂O₆ (Fructose)

Question 36

How is commercial glucose obtained?

Answer 36

Commercial glucose is obtained by hydrolyzing starch using dilute H₂SO₄ at 393 K under pressure.

Question 37

What are the conditions for starch hydrolysis to glucose?

Answer 37

Boiling starch with dilute H₂SO₄ at 393 K and 2-3 atm pressure.

Question 38

Write the general chemical equation for starch hydrolysis.

Answer 38

(C₆H₁₀O₅)n + nH₂O → nC₆H₁₂O₆ (Glucose)

Question 39

What type of sugar is glucose?

Answer 39

Glucose is an aldohexose, meaning it has six carbon atoms and an aldehyde group.

Question 40

What is another name for glucose?

Answer 40

Glucose is also known as dextrose.

Question 41

What larger carbohydrates are made from glucose?

Answer 41

Starch and cellulose are polymers of glucose.

Question 42

Why is glucose considered important in nature?

Answer 42

Glucose is one of the most abundant organic compounds on Earth.