The protein factories

The idea

Ribosomes are tiny structures, free in the cytoplasm or attached to the endoplasmic reticulum, that are the sites of protein synthesis.

Who makes the proteins?

Cells need huge numbers of proteins to build and run their parts.

Which tiny structures do you think do the building?

• Ribosomes
• The cell wall
• The vacuole

Build a protein

Slide the chain longer. Then move the ribosome onto the ER.

Ribosomes

Ribosomes are tiny structures, present free in the cytoplasm or attached to the endoplasmic reticulum. They are the sites of protein synthesis.

Remember: one large and one small subunit come together to form a ribosome.

• Where | What the ribosome does
• Free in the cytoplasm | makes proteins
• Attached to the ER | makes proteins

Notes

Ribosomes are tiny structures, free in the cytoplasm or attached to the ER. They are the sites of protein synthesis.

Check yourself

Ribosomes are the sites of…

Where can ribosomes be found?

Ribosomes are called the…

Which organelle makes the ribosomal subunits?

• protein synthesis — correct. Yes.
• energy release. That is done in mitochondria.
• waste removal. That is done by lysosomes.
• Free in the cytoplasm or attached to the ER — correct. Yes.
• Only in the nucleus. They work in the cytoplasm.
• Only outside the cell. They are inside the cell.
• protein factories — correct. Yes.
• powerhouses. That is the mitochondria.
• post office. That is the Golgi apparatus.
• The nucleolus — correct. Yes. They then assemble in the cytoplasm.
• The vacuole. The vacuole stores materials.
• The cell wall. The wall does not make them.