Sb Molecules And Proteins

Front 1

Heme group:
1. What is the geometry?
2. Is it hydrophobic or hydrophilic
3. What does it bind?
4. What type of iron ion does normal Heme bind

Back 1

1. Planar
2. hydrophobic
3. Oxygen
4. Ferrous (2+)

Front 2

Globin
1. What are the different types of globin
2. How many globin subunits are in hemoglobin?
3. What is the function of globin wrt to Heme group

Back 2

1. alpha, beta, gamma
2. Four. Two alpha, two non-alpha
3. Shield hydrophobic heme group from water

Front 3

Hemoglobin Saturation:
1. What are [Hb] levels in normal and anemic people?
2. Cyanosis occurse when deoxy-Hb levels are greater than what?
3. How well does Hb bind O2?
4. What is the p50 of Hb?
5. What is atmospheric pO2?

Back 3

1. 15 g/dl, less than 12 g/dl
2. 5 g/dl
3. 1.34 ml/g
4. 27 mmHg
5. 160 mmHg

Front 4

Right-shift (Bohr effect)
Up or down?
1. pH
2. [CO2]
3. 2,3 BPG
4. Temperature

Back 4

1. down
2. up
3. up
4. up

Front 5

2,3 bisphosphoglycerate
1. How does it change Hb affinity to oxygen?
2. How does it affect HbF

Back 5

1. Allosteric inhibitor, decreases O2 affinity
2. HbF is insensitive to 2,3 BPG

Front 6

Myoglobin
1. What is the difference in shape of the O2 saturation curve between myoglobin and hemoglobin?
2. What is the p50 of myoglobin?

Back 6

1. Myoglobin is not cooperative, so the O2 saturation curve is not sigmoidal.
2. 2 mmHg

Front 7

Glycated Hb (HbAlc)
1. What is attached to hemoglobin, and where is it attached?
2. What level of HbAlc indicated diabetes?

Back 7

1. Glucose attached permanently to n-terminus of beta chain
2. <7.5%

Front 8

Methemoglobin
1. What is the difference between methemoglobin and regular hemoglobin?
2. What enzyme normally regulates methemoglobin? At what level?

Back 8

1. Orin oxidized to ferric ion (Fe3+), binds oxygen too strongly
2. Methemoglobin reductase, 2%

Front 9

Protein signal sequences
What are typical signal sequences for:
1. Import into nucleus
2. Export from nucleus
3. Import into ER

Back 9

1. basic AA
2. alternating neutral AA
3. neutral AA

Front 10

NPC
1. What part of the NPC recognizes and binds to the cargo protein complex?
2. What part of the cargo protein complex is recognized?

Back 10

1. Fibrils
2. Nuclear import protein (adapter protein)

Front 11

GEF and GAP
1. what do GEFS do?
2. what do GAPs do?

Back 11

1. Guanine exchange factors catalyze exchange of GTP for GDP (GDP --> GTP)
2. GTPase activating proteins active GTPase, which converts GTP to GDP)

Front 12

1. What GAP/GEF switch controls nuclear pore import?

2. Which is associated with loading cargo?

3. Which is associated with unloading cargo?

4. Which enzyme is in the cytosol? nucleus?

5. For nuclear export, which form of Ran promotes binding? discharge?

Back 12

1. Ran, controlled by Ran-GTPase
2. Ran-GDP (switched by Ran-GAP)
3. Ran-GTP (switched by Ran-GEF)
4. Ran-GAP in cytosol, Ran-GEF in nucleus
5. Ran-GTP promotes binding, Ran-GDP promotes discharge

Front 13

Activation and deactivation of nuclear transport
1. How is nuclear transport switched off?
2. How is it switched on?

Back 13

1. Protein kinases phosphorylate AA near NLS
2. Phosphotase dephosphorylates these AA's, unmasking NLS

Front 14

1. What form do proteins need to take to be transported into mitochondria? 2. When does this occur wrt to translation?

Back 14

1. Proteins must be unfolded
2. Post-translational

Front 15

1. what does profilin do?
2. What does Thymosin do?
3. What does ARP do?
4. What does Formin do?
5. What do rho GTPases do?

Back 15

1. binds to monomer, promotes actin polymerization
2. Stabilizes actin monomer
3. Composed of Arp3 and Arp2 subunits, binds to actin monomers at minus end to nucleate new actin filament at 70 degree angle to pre-existing chain. Forms "dendritic arrays"
4. Nucleates new linear array of actin filament, builds from plus end (2 cups)
5. Regulate action of formin, ARP

Front 16

1. What are the two steps of actin polymerization?
2. What are the two forms of actin?
3.

Back 16

1. Nucleation (rate limiting, formation of trimer), elongation
2. G-actin, F-actin

Front 17

Which myosin type moves towards minus end of actin filament?

Back 17

VI

Front 18

1. What are the two classes of MT motor proteins?
2. Which ones move to the plus end? Minus end?
3. Which class is more like myosin?
4. How does Dynein attach to cargo?

Back 18

1. Dyneins and kinesins
2. Dyneins move to minus end, Kinesins move to plus end
3. Kynesin (two globular heads, double helical tail)
4. Dynactin, spectrin, ankyrin, ARP1

Front 19

1. Where do microtubules originate?
2. How is the polarity arranged?

Back 19

1. At a central centriole
2. Generally plus ends point peripherally except in neuronal dendrites ,where MTs are arranged in mixed polarity. In axon, + ends are still outward

Front 20

What is an axoneme?

Back 20

Stable of array of MT in cilia and flagella. 9 outer dimers around a sintral singlet MT anchored at a centriole, dynein arms attached to dimer allow sliding and bending. Incomplete dimer,