Hormones
NCERT Reference: Chapter 10 – Biomolecules – Page 279
Quick Notes
- Hormones are non-nutrient chemical messengers.
- Produced in trace amounts by endocrine glands.
- Secreted directly into the bloodstream.
- Regulate growth, metabolism, and development.
- Examples include insulin, thyroxine, adrenaline, oestrogen, and testosterone.
Full Notes
Hormones are biomolecules that regulate various physiological activities in living organisms.
They are chemical messengers secreted by endocrine glands in trace amounts and carried through the bloodstream to specific target organs. They are crucial for the regulation of physiological functions such as:
- Growth
- Metabolism
- Development
- Reproductive functions
Hormones do not supply energy or form structural components of cells, but they profoundly influence cellular and systemic activities.
Examples
- Insulin – Regulates blood sugar levels.
- Thyroxine – Controls metabolism.
- Adrenaline – Prepares the body for 'fight or flight' response.
- Oestrogen and Testosterone – Regulate reproductive functions.
Summary
- Hormones are chemical messengers secreted by endocrine glands in very small amounts.
- They travel via the bloodstream to specific target organs.
- They regulate growth, metabolism, development, and reproduction.
- Key examples include insulin, thyroxine, adrenaline, oestrogen, and testosterone.