Starter  Collect your plenary sheet from last lesson- answers on power point on BLOG  How many spec points from have we covered so far?

Organelles questions 1.Which organelles have a membrane? (6) 2.Which organelles have a double membrane? (3) 3.What are the membrane bound sacs of the ER called? 4.Which is the largest organelle?

1.Nucleus, ER, golgi apparatus, mitochondria, chloroplasts, lysosomes 2.Nucleus, mitochondria, chloroplasts 3.Cisternae 4.Nucleus

Learning objectives  Outline the interrelationship between the organelles involved in the production and secretion of proteins (spec point g)  Recall the role of the cytoskeleton of the cell  Explain the importance of the cytoskeleton of the cell

Division of labour  Cell organelles work together to get jobs done. This is called division of labour  WE only need to look at protein synthesis and secretion for the spec

Task  You have been given a sheet with stages blanked out  Write statements to explain what is happening at each stage – knowledge from functions of organelles (linking)

3.Ribosome makes a protein (it uses the mRNA as a recipe/template) 4.Rough ER packages the protein into a vesicle and sends it to the golgi 5.The vesicle fuses to the golgi depositing the protein 6.Golgi processes and packages the protein 7.Golgi vesicle pinches off the golgi containing the modified protein 8.Vesicle fuses with the cell SURFACE membrane 9.Cell surface membrane opens to release the protein

How many organelles are involved in the process?  Nucleus  Ribosome  Rough ER  Golgi I get 4 key ones

Learning objectives  Outline the interrelationship between the organelles involved in the production and secretion of proteins (spec point g)  Recall the role of the cytoskeleton of the cell  Explain the importance of the cytoskeleton of the cell

 How are things held in place in the cell?  How do things know where to move in a cell? Is it random movement?

Cytoskeleton – key spec points  Mechanical strength  Transport  Cell movement

Cell strength A series of protein fibres keep the cells shape stable by providing a internal framework (cytoskeleton)

Cell movement  Actin filaments can move against eachother They are responsible for the movement seen in white blood cells  Microtubules (approx 25nm diameter cylinders) Made from a protein tubulin They can move a microorganism through a liquid (flagellum) or move a liquid past a cell (cilia)

Transport of organelles and vesicles within a cell Actin filaments can move some organelles around inside the cell Other proteins on the microtubules inside the cell can move the organelles/vesicles along the fibres These proteins are known as microtubule motors (page 18 extension)

Examiners tip  All movement requires energy (ATP) cilia outside the cell and organelles within the cell  You can get a mark for mentioning that

Individual study task  Research from your text eukaryotic DNA  What is a prokaryotic cell?  How can you distinguish between a prokaryotic and eukaryotic cell?  How is eukaryotic DNA different from prokaryotic DNA?

Plenary  Explain the importance of the cytoskeleton of the cell  Paper to hand in