Sorting 2

Question 1

What are the 5 major parts of the mitochondria anatomy?

Answer 1

Outer Membrane, Inner Membrane, Intermembrane space, matrix and cristae(outside)

Question 2

What is the movement of proteins crossing outer or inner mitochondrial membranes called?

Answer 2

Translocation

Question 3

What directs proteins to the correct compartment in the mitochondria?

Answer 3

Signal Sequences

Question 4

Describe the amphiphillic alpha helix

Answer 4

Positively charged residues on end and uncharged hydrophobic residues on the other

Question 5

What are the 4 major translocators in the mitochondiral membrane?

Answer 5

SAM, TIM, TOM and OXA

Question 6

SAM

Answer 6

Sorting and Assembly Machinery

Question 7

TIM

Answer 7

Translocase of the inner membrane

Found inner membrane

Question 8

TOM

Answer 8

Translocase of outer membrane

Insert of all nuclear encoded proteins through outer membrane

Question 9

OXA

Answer 9

Mediates insertion of proteins synthesized in mitochondria

Question 10

Two types of TIM

Answer 10

TIM 23

TIM 22

Question 11

TIM 23

Answer 11

Translocates soluble proteins into matrix and helps insert membrane proteins in inner membrane

Question 12

TIM 22

Answer 12

Mediates insertion of specific subclass of proteins

Question 13

Describe the import of outer membrane proteins

Answer 13

1. First fed through TOM
2. Binds to chaperone protein
3. Binds to SAM in intermembrane/outermembrane space
4. Folds and inserts in to outer membrane as a porin

Question 14

How is ATP used in the import of protein into the mitochondria matrix?

Answer 14

1) Atp is used to remove HSP70 in the cytosol prior to feeding through the TOM
2) Expenditure of ATP to add HSP70 in the matrix
3) ATP is used to fold via HSP60

Question 15

____ are beta-barrels while ____ are alpha helix

Answer 15

Porins; amphiphilic

Question 16

SRP

Answer 16

Signal Recognition Particle
Made up of 6 diff polypeptide proteins and a backbone of RNA molecules. Also has a large hydrophobic pocket with plenty of methiones. Helps identify that protein is for ER

Question 17

What are the binding sites of the SRP?

Answer 17

1) Elongation binding site of the ribosome
2) Signal sequence of the protein
3) SRP Receptor

Question 18

What impact does SRP binding to ribosome have on the activity?

Answer 18

By binding to the elongation factor binding site, it halts protein synthesis

Question 19

Translocator of ER membrane has a ____ complex with ___, ____, ___ subunits.

Answer 19

SEC61
Alpha
Beta
Gamma

Question 20

ER translocator water-filled pore opens with identification of ____ causing ____ and displaces ____.

Answer 20

Signal Sequence
Start-transfer signal
Plug

Question 21

Translocation of soluble proteins have just ____ allowing entire protein to fall through. Transmembrane proteins have a ____ and ____

Answer 21

1) Start-Transfer
2) Start-transfer
3) stop-transfer

Question 22

How many minimal A.A in a ER signal sequence and what is it’s property?

Answer 22

At least 8 Hydrophobic A.A

Question 23

ER signal sequence consist of

Answer 23

SRP receptor and SRP(signal recog. particle)