Endoplasmic Reticulum And Secretory Pathway

Question 1

What is a signal peptide ?

Answer 1

Short peptide present at the N-terminus of the majority of newly synthesised proteins that are destined towards the secretory pathway.

Question 2

What are the features of the rough endoplasmic reticulum?

Answer 2

• Found near the nucleus
• Originates form nuclear membranes
• Mainly composed of Cristina
• Synthesis, folding and transport of proteins

Question 3

What are some features of the smooth endoplasmic reticulum?

Answer 3

• Found closer to cell membrane
• Originates from rough endoplasmic reticulum by giving off the ribosomes
• Mainly composed of tubuels
• Synthesis and transport of lipids
• Mainly present in lipid forming cells

Question 4

What are signal sequences ?

Answer 4

Nucleotides that are going to code for amino acids and determine the destination of the protein - are recognised by enzyme systems within the cell that transport the protein to the correct destination (2 ribosome locations).

Question 5

What organelles are newly synthesised proteins targeted to?

Answer 5

• Endoplasmic reticulum
• Nucleus
• Mitochondria
• Peroxisomes
• Chloroplast