🧬 Part 1: Ribosomes – The Protein Factories

🔹 What are Ribosomes?

Definition:
Ribosomes are tiny structures inside cells that make proteins. They are not surrounded by a membrane, unlike many other organelles. They’re made up of rRNA (ribosomal RNA) and proteins.

Think of them as tiny machines that read instructions and build proteins, like a kitchen reads a recipe and cooks a dish.

🔍 Structure of Ribosomes

• Composed of:
  • 60% ribosomal RNA (rRNA)
  • 40% proteins
• No outer membrane
• Smaller than most organelles

🧠 Mnemonic: “Ribosomes = RNP” → RNA and Protein
How it helps: Whenever you hear “ribosome,” remember RNP: it is RNA + Protein.

📍 Where Are Ribosomes Found?

Eukaryotic Cells (like animal and plant cells):

• Attached to rough endoplasmic reticulum (RER) → called bound ribosomes
• Freely floating in the cytoplasm → called free ribosomes

Prokaryotic Cells (like bacteria):

• Only free ribosomes in cytoplasm

📌 Real-life comparison:
Ribosomes on RER are like workers in a factory assembly line (fixed spot), while free ribosomes are like freelancers, working independently.

⚙️ Functions of Ribosome

Main job: Protein synthesis (making proteins).

• Cells like pancreas (produce enzymes) or brain cells (need neurotransmitters) have many ribosomes because they need lots of proteins.