4.1 Biological Molecules

This section explores the fundamental building blocks of life – biological molecules. We will focus on identifying the chemical elements that compose the three major types: carbohydrates, fats, and proteins.

Carbohydrates

Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen. The general formula for carbohydrates is $CH_n(O_n)_m$, where 'n' and 'm' are positive integers.

Chemical Elements:

• Carbon (C)
• Hydrogen (H)
• Oxygen (O)

Fats (Lipids)

Fats, also known as lipids, are primarily composed of carbon, hydrogen, and oxygen. However, they contain a much higher proportion of hydrogen compared to carbohydrates. The chemical formula for a typical fat is derived from the hydrocarbon chains that make up triglycerides.

Chemical Elements:

• Carbon (C)
• Hydrogen (H)
• Oxygen (O)

Proteins

Proteins are complex organic molecules built from amino acids. The standard amino acid formula is $CH_2(R)_2-COOH$. This indicates that all amino acids contain carbon, hydrogen, oxygen, and nitrogen. Some amino acids also contain sulfur.

Chemical Elements:

• Carbon (C)
• Hydrogen (H)
• Oxygen (O)
• Nitrogen (N)
• Sulfur (S) - in some amino acids

Summary Table