💡 Why proteins are important?
Proteins are used to:
- Build muscles (like bricks in a house)
- Make enzymes (help chemical reactions)
- Build hormones (messengers in the body)
🏗️ How Ribosomes Are Made
- In eukaryotic cells, ribosomes are made in the nucleolus (a part inside the nucleus).
- Ribosomal proteins come into the nucleolus and combine with rRNA.
- They form two parts:
- Small subunit
- Large subunit
- These parts leave the nucleus and combine in the cytoplasm when protein-making starts.
- When not working, they stay separated.
🎓 Mnemonic: “Ribo Subunits Go SPLiT” → Small + Large Inactive Together
Helps remember: Ribosome = two parts (small + large), which join only when working.
🧪 How Ribosomes Make Proteins (The 3 Key RNAs)
- mRNA (Messenger RNA):
- Carries the blueprint (recipe) from DNA.
- Brings it to the ribosome.
- tRNA (Transfer RNA):
- Brings the right amino acids (building blocks of proteins) to the ribosome.
- Ribosome reads the mRNA, tRNA brings amino acids, and the ribosome links them together to make a protein chain.
📘 Real-life example:
It’s like mRNA = recipe, tRNA = ingredients, ribosome = chef.
🧪 Svedberg Units (Size of Ribosomes)
Ribosomes are measured in Svedberg units (S), based on how fast they settle during centrifugation (spinning in lab).
- Eukaryotic ribosome = 80S
- Large subunit = 60S
- Small subunit = 40S
- Prokaryotic ribosome = 70S
- Large subunit = 50S
- Small subunit = 30S
🎓 Mnemonic: “Euk 80/60/40 – Pro 70/50/30”
Say it like a rhyme. Helps you remember values in order.