Protein Transport

Question 1

Protein Translocators

Answer 1

When proteins are transported across membranes, they are unfolded and transported via protein translocators

Question 2

Difference between transport across nucleus and transport across membranes

Answer 2

nuclear pores act as selective gates, protein translocators transport across membranes

Question 3

signal sequences

Answer 3

these direct proteins to the correct compartment
they are short amino acid sequences within a protein
however, translocation occurs in the absence of these

Question 4

nuclear localization sequence

Answer 4

a short sequence of amino acids that mediates the transport of nuclear proteins into the nucleus
a protein needs a nuclear localization sequence to enter the nucleus

Question 5

transport across membranes

Answer 5

they unfold to enter the mitochondria and chloroplasts
a receptor on the outer mitochondrial membrane recognizes their signal sequence
they complex, diffuse to a contact site and are translocated by protein translocators and chaperones

Question 6

subcellular fractionation

Answer 6

a technique used to separate components of cells

Question 7

flow cytometry

Answer 7

uses laser beams of various intensities to determine the characteristics of cells

Question 8

actin filaments

Answer 8

for cell movement

Question 9

lamellipodium

Answer 9

protrusions cells use for movement

a network of actin filaments with their plus ends close to the membrane

Question 10

fillapodia

Answer 10

thin stiff ends of actin filaments