1) b) ii) Synthesis of Membrane Compartments

Question 1

where are proteins and lipids synthesised

Answer 1

endoplasmic reticulum

Question 2

Which part of the endoplasmic reticulum are lipids synthesised

Answer 2

Lipids are synthesised in the smooth
endoplasmic reticulum (SER) and inserted into its membrane

Question 3

State a difference between smooth and rough endoplasmic reticulum

Answer 3

Rough ER (RER) has ribosomes on its
cytosolic face while
smooth ER (SER) lacks ribosomes.

Question 4

Where does the synthesis of all proteins begin?

Answer 4

Cytosolic ribosome

Question 5

What is a signal sequence

Answer 5

A signal sequence is a short stretch of amino acids at one end of the polypeptide that determines the eventual location of a protein
in a cell.

Question 6

Describe the synthesis of Transmembrane proteins

Answer 6

Transmembrane proteins carry a signal
sequence, which halts translation and directs the ribosome synthesising the protein to dock with the ER, forming RER.
Translation continues after docking, and the protein is inserted into the membrane of the ER.

Question 7

Describe the synthesis of Cytosolic Proteins

Answer 7

The synthesis of cytosolic proteins is
completed there, and these proteins remain in the cytosol.