Biological Molecules and Their Composition: Building Blocks of Life

Biological molecules are like the Lego pieces of life—they come together in different ways to form everything living.

 

What Are Biological Molecules?

Biological molecules are essential chemicals that make up cells and organisms. They provide energy, structure, and the tools needed for life processes.

Key Biological Molecules:

1. Carbohydrates: Quick energy providers.
2. Fats (Lipids): Long-term energy storage and insulation.
3. Proteins: Building blocks for growth and repair.
4. Vitamins: Essential for specific bodily functions.

 

 

Chemical Composition of Biological Molecules

 

Biological Molecule	Chemical Elements
Carbohydrate	Made of the elements carbon (C), hydrogen (H), and oxygen (O). Example: Glucose $C_6H_{12}O_6$ is a simple sugar.
Fats (Lipids)	Made of carbon (C), hydrogen (H), and oxygen (O). Formed from glycerol and fatty acids.
Proteins	Made of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sometimes sulfur (S). Built from smaller units called amino acids.

 

Building Larger Molecules from Smaller Ones

Carbohydrates

• Carbohydrates are made up of long chain simple sugars
• Glucose is an example of a simple sugar (i.e a monosaccharide)
• If you combine 2 glucose molecules together you form maltose (a disaccharide)
• When you combine a lot of glucose molecules together you can form starch, glycogen or cellulose (a polysaccharide)

 

Proteins

• Proteins are long chain amino acids, there are roughly 20 different amino acid types
• These amino acids have different 'R' groups but have the same/similar basic structures
• As amino acids can be arranged and joined in any order it means there are thousands of different proteins that can be formed. Even a small difference in order can create a completely different protein to form

 

 

Fats (Lipids)

• The basic unit of a fat (lipid) is 1 glycerol molecule chemically bonded to 3 fatty acid chains
• These fatty acids can have varying structures and sizes
• The majority of fats (lipids) in the body are formed of triglycerides
• At room temperature, lipids are split/divided into fats and oils