Vitamins — Groups, Roles & Deficiency Diseases (Avitaminoses)
Grade 8 Biology — Metabolism & Energy Series
Quick Recap from Our Previous Lesson
In our last lesson on Metabolism and Energy, we briefly introduced vitamins as essential organic micronutrients. Today, we dive deep into their classification, biological roles, and what happens when we don't get enough — avitaminoses (vitamin deficiency diseases).
1. What Are Vitamins?
Vitamins are organic compounds that perform specific biological functions essential for normal growth and functioning of the organism. The term "vitamine" was coined by the Polish biochemist Casimir Funk in 1912 (from Latin vita = life + amine).
Key Points:
- Vitamins do NOT provide energy directly — they act as regulators and coenzymes in vital biochemical reactions.
- They help release energy from food but are not fuels themselves.
- Our bodies cannot manufacture sufficient amounts of most vitamins, so we must obtain them from food.
- Only tiny amounts (micrograms or milligrams) are needed daily — that's why they are called micronutrients.
