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Flashcards in MCBG 11 Deck (32):
1

Protein sorting. Which organelles use the ER to get their proteins?

Lysosomes
ER

2

Which organelles get their proteins from free cytosolic ribosomes?

Nucleus
Mitochondria
Peroxisomes

3

What is required for protein sorting?

Signal
Receptor
Translocational machinery
Energy

4

How do protein get to the ER?

mRNA (specific translocational sequence) and a ribosome in the cytoplasm get bound by a SRP (signal recognition particle) where it is transported to the ER

5

How is PDI (an ER resident protein) retained
in the ER and not secreted?

The golgi body has retrograde secretions back to the ER

6

What is the signal used to get golgi vesicles back to the ER (WHERE IS IS FOUND SPECIFICALLY)

KDEL on the C-terminus

7

What does the signal for retrograde transportation back to the ER bind to?

KDEL receptor which forms a vesicle with a COPI coat

8

Whats the signal in lysosome import?

Mannose-6-phosphate

9

Lysosome import. What happens for to the signal so it know where its going?

In Golgi M6P binds to

10

Whats the mitochondrial signal called? WHERE IS IS FOUND SPECIFICALLY

MTS Mitochondrial targeting signal
N-terminus

11

Whats MTS?

Mitochondrial targeting signal

12

What are the additional proteins needed in MITO import?

Chaperone proteins

13

MITO. Energy?

Yes. Transporters

14

Nuclear transport. What is the signal?

NLS. Nuclear localising signal

15

What are the additional proteins needed in Nuclear import?

Importin

16

Describe how the nuclear protein in imported?

PP chain binds to importin (alpha and beta) this transports it into the cell via a nuclear pore. RanGTP binds to Importin, displaces the protein and is transported out of the cell. GTP->GDP causes ran to be recycled back to the nucleas

17

What are the two ways of Short term regulation of enzyme activity

1. Substrate and product concentration
2. Change in enzyme conformation
(A)llosteric. Allosteric regulation
(B)onds. Covalent modification
(C)leavage. Proteolytic cleavage

18

What are the two ways of LONG TERM REGULATION of enzyme activity

1. Change in rate of protein synthesis
2. Change in rate of protein degradation

19

What is Phosphofructokinase?

allosterically regulated and sets the pace of glycolysis.

20

What activates Phosphofructokinase? What regulation is this?

AMP, fructose-2,6-
bisphosphate
Allosteric

21

What deactivates Phosphofructokinase?
What regulation is this?

ATP, citrate, H+
Allosteric

22

What is haemophilia?

mostly inherited genetic disorder that impairs the body's ability to make blood clots. X-linked recessive disorders

23

What are the two types of haemophilia?

There are two main types of haemophilia: haemophilia A, which occurs due to not enough clotting factor VIII, and haemophilia B, which occurs due to not enough clotting factor IX.

24

Why is protein phosphorylation so effective? 3/5

• Adds 2 negative charges
• A phosphoryl group can make H-bonds
• Allow for amplification effects
• Rate of phosphorylation/dephosphorylation can be adjusted
• Links energy status of the cell to metabolism through ATP

25

define the term zymogen

inactive substance which is converted into an enzyme when activated by another enzyme

26

Coagulation cascade. Whats the intrinsic pathway?

XII
XI
IX +VIII
X + V
II THROMBIN
I FIBRIN

27

Coagulation cascade. Whats the extrinsic pathway?

III (Tissue factor)
VII
X
II
I

28

How does the Coagulation cascade get activated?

By the extrinsic pathway (SPARK)
At a epithelial break, platelets and Tissue factors form at the blood clot. This activates the extrinisic cascade forming thrombin which activates the intrinsic pathway (WORK HORSE)

29

Whats a thrombosis

The formation of a solid mass of blood within the circulatory system of a living body

30

What factors get activated by thrombin?

All odd numbers (kinda)
(2) 5 7 (X9X)8 11 13

31

What does XIII do?

Connects the fibrin strands with cross strands

32

What inactivates the coagulation cascade? 2

Thrombin forms
plasmin (breaks down crosslinks)
Stimulates antithrombrin ( inhibits thrombin and Factor X