Organelles In Protein Synthesis

Question 1

Proteins are made in which organelle?

Answer 1

Ribosomes (small organelle that floats free)

Question 2

What do the proteins on the RER do?

Answer 2

Make proteins which code for amino acids that are excreted or attached to the cell membrane. They have no membrane themselves and are constructed of RNA molecules made in the nucleolus of the cell which is where ribosomes are made.

Question 3

What do the free ribosomes do?

Answer 3

The free ones in the cytoplasm make proteins that stay in the cytoplasm.

Question 4

The golgi apparatus in protein production

Answer 4

The golgi is similar in structure to the ER. It is a compact structure, not containing ribosomes it modifies proteins and packs them into vesicles , they may be secretory vesicles designed to leave the cell.

Question 5

Protein production steps (Step 1)

Answer 5

Proteins are synthesised on the ribosomes bound to the Endoplasmic recticulum.

Question 6

Protein production steps (Step 2)

Answer 6

They pass into its cristetnae and are packaged into transporting vesicles.

Question 7

Protein production steps (Step 3)

Answer 7

Vesicles containing the newly synthesised proteins move towards the golgi apparatus via the movement of the cytoskeleton.

Question 8

Protein production steps (Step 4)

Answer 8

The vesicles fuse with cis face of the golgi apparatus and proteins enter. The proteins are structurally modified before leaving the golgi apparatus in vesicles from its trans face.

Question 9

Protein production steps (Step 5)

Answer 9

Secretory vesicles carry proteins that are to be released from the cell. The vesicles move towards and fuse to the plasma membrane, releasing the contents through exocytisis some form lysosomes which contain enzymes for the cells use.

Question 10

The cytoskeleton functions and how it may help in protein production

Answer 10

The cytoplasm is a network of protein threads what run through these are known as cytoskeleton
They are arrange as microfilaments (small solid strands) and microtubles (tiny protein cylinders)

Question 11

The four main functions

Answer 11

The two components of the cytoskeleton support the cells organelles in position.
They strengthen the cell and keep its shape.
Responsible for the movement of materials in and out of a cell for example the chromosomes involved in cell division
The proteins of the cytoskeleton can also cause movement e.g the cilia and flagellum is caused by the cytoskeleton protein filaments that run through them. So in the case of single cells that have a flagellum e.g (Sperm) the skeleton propels the whole cell.