Chemical basis of life

Question 1

How many elements does the human body comprise?

Answer 1

At least 25 elements out of 92 present in the environment.

Question 2

What are the four main elements present in the human body?

Answer 2

Oxygen, nitrogen, carbon, hydrogen.

Question 3

Name other essential chemical elements for living beings.

Answer 3

• Phosphorus
• Sulfur
• Potassium
• Calcium

Question 4

What percentage of the human body is made up of oxygen?

Answer 4

65%

Question 5

What percentage of the human body is made up of carbon?

Answer 5

18%

Question 6

What percentage of the human body is made up of hydrogen?

Answer 6

10%

Question 7

What percentage of the human body is made up of nitrogen?

Answer 7

3%

Question 8

What distinguishes organic compounds from inorganic compounds?

Answer 8

Organic compounds contain carbon; inorganic compounds do not.

Question 9

What are biological molecules?

Answer 9

Organic compounds that build up the living components.

Question 10

List the types of biological molecules.

Answer 10

• Carbohydrates
• Lipids
• Proteins
• Nucleic acids

Question 11

What are examples of inorganic molecules?

Answer 11

• Water
• Minerals
• Gases

Question 12

What are carbohydrates primarily composed of?

Answer 12

Carbon, hydrogen, and oxygen.

Question 13

What is the general formula for carbohydrates?

Answer 13

Cx(H2O)y

Question 14

Name some abundant carbohydrate foods.

Answer 14

• Rice
• Potatoes
• Buns

Question 15

Fill in the blank: The organic compounds that build up the living bodies are known as _______.

Answer 15

[biological molecules]