5

Question 1

Micelles

Answer 1

: lipids with bulky heads and a single hydrophobic fatty acid tail are wedge-wedge-shaped and pack into spherical structures called micelles

Question 2

mobility of proteins demonstrated using FRAP

Answer 2

fluorescent dyed proteins could be bleached using a laser.
If they moved, bleached area would fluoresce
If no movement, bleacher area would not
Fluorescence appeared in bleached area

Question 3

HELA cell line

Answer 3

immortal cell line; shows complexity of processes; importance of organisation within the cell

Question 4

in the endomembrane system

Answer 4

nuclear envelope, ER, golgi apparatus, lysosomes, vesicles, vacuoles, plasma membrane

Question 5

not in the endomembrane system

Answer 5

mitochondria, chloroplasts, peroxisome

Question 6

peroxisome

Answer 6

protein structure highly conserved; no DNA but act like living organism; detoxification and transfer H from various compounds to O, forming hydrogen peroxidase; contain many different enzymes and are involved in several metabolic reactions, including the breakdown of fatty acids and synthesis of certain types of organic molecules like cholesterol and some types of phospholipid

Question 7

Glyoxysome

Answer 7

specialised peroxisome in plant tissue; break down fat reserves in seeds to produce sugars for the growing seed

Question 8

Protein ultimate roles in cell

Answer 8

Proteins produced on free ribosomes are sorted after they are translated
These proteins often contain amino acid sequences called signal sequences that allow them to be recognised and sorted
Proteins with no signal sequence remain in cytosol
Proteins destined for mitochondria or chloroplasts have a signal sequence at amino ends
Proteins targeted to nucleus have an internally located signal sequence
These are called nuclear localisation signals, and enable proteins to move through pores in the nuclear envelope

Question 9

Signal recognition particle

Answer 9

binds to both the single sequence and free ribosome, and pauses translation
SRP binds with receptor in TET so the ribosome is now associated with RER
SRP receptor brings the ribosome to a channel int he membrane of the RER
SPR dissociates and translation continues, allowing the growing polypeptide chain to be threaded through the channel