Lesson 3 – protein synthesis – what you don’t know Which organelles are involved in processing proteins? Starter: Complete the card sort 1 more time for a eukaryotic cell. THE RACE IS ON

Protein Synthesis (of a hormone) RECALL From GCSE 1) name some different types of protein. 2) explain protein synthesis

What you DON’T know Protein is assembled by the ribosome on the ER. It travels THROUGH the ER and is pinched off into a vesicle. Vesicle travels to the golgi body. Golgi apparatus modifies the protein so it is ready for release. The protein is (in this case) packed into a vesicle and moved to the cell surface (by the cytoskeleton) and is secreted.

Newly transcribes mRNA goes into the cytoplasm. mRNA on ribosomes are translated into a string of amino acids which is directed to the lumen of the endoplasmic reticulum. Post translation modification begins here. Transport vesicles transport proteins to the golgi apparatus. Post translational modification occurs in the golgi body. Proteins to leave the cell are packaged into secretory vesicles. Proteins that stay in the cell are packaged into lysosome or storage vesicles.

Task 1 Complete the labelling task looking at 2 eukaryotic cells.

Prokaryotic and eukaryotic cells

Prokaryotes – 1 minute pillus What are the key differences?

Key differences Cell wall – made of peptidoglycan (Murein) Ribosomes are smaller than eukaryotes. Outside slippery capsule. Single loop of DNA Occasionally some plasmids - v small loops of DNA No nuclear membrane Flagella instead of undulipodia ( in eukaryotes e.g. sperm tail) Often have hair like appendages called pili (pilus)

Prokaryotes and Disease resistance

Dangers of Antibiotics

BUT …. If you don’t finish your antibiotic course. ….

Dangers of Antibiotics

Get ill again - take MORE antibiotics ….

Dangers of Antibiotics

NEW EVIL STRAIN OF BACTERIA! Muhahaha

But how does that happen? Bacteria can become resistant to antibiotics (e.g. MRSA) because the plasmids code for a resistance gene. They can share these plasmids and pass them onto daughter cells!

How do we use prokaryotes?