BIOCHEMISTRY & BIOPHYSICS

Question 1

What does cGMP stand for?

Answer 1

cyclic guanosine monophosphate

Question 2

What is cyclic guanosine monophosphate or cGMP

Answer 2

A second messenger or signalling molecule

Question 3

Name two pathways cyclic guanosine monophosphate or cGMP is involved in?

Answer 3

1. Nitric oxide cGMP pathway in smooth muscle
2. cGMP pathway in photo transduction in the retina

Question 4

How is cGMP generated?

Answer 4

GTP via enzyme guanylyl cyclase

GTP + guanyly cyclase =cGMP

Question 5

What enzyme is responsible for cGMP convertion to GTP?

Answer 5

Phosphodiesterase

Question 6

What does GTP stand for?

Answer 6

Guanosine triphosphate

Question 7

In the nitric oxide cGMP smooth muscle pathway what happens after G protein activation?

Answer 7

Production phospholipase C

Question 8

In the nitric oxide cGMP smooth muscle pathway what happens after G protein activation causes phospholipase C.

What happens next?

Answer 8

Activation of IP3

IP3 = inositol 1,4,5 trisphophate

Question 9

In the nitric oxide cGMP smooth muscle pathway what happens after activation of IP3?

Answer 9

Increase calcium levels in the cell

Question 10

In the nitric oxide cGMP smooth muscle pathway activation of IP3 leads to increase calcium levels in the cell.

What happens next

Answer 10

L arginine is then converted to citrulline and nitric oxide

Question 11

Which key cellular second messenger signalling molecule is generated from the precursor amino acide L arginine?

(SIzer & Neil)

Answer 11

Nitric oxide

Question 12

In the nitric oxide cGMP smooth muscle pathway, what happens after nitric oxide generation in endothelial cell?

Answer 12

Nitric oxide binds to nitric oxide receptor found in neighbouring smooth muscle

Question 13

In the nitric oxide cGMP smooth muscle pathway, nitric oxide binds to nitric oxide receptor found in neighbouring smooth muscle. That does this trigger?

Answer 13

Activates the enzyme guanylyl cyclase with convertion of GTP to cGMP

Question 14

In the nitric oxide cGMP smooth what is the function of cGMP?

Answer 14

Activates phosphokinase G

Question 15

In the nitric oxide cGMP smooth what is the function of cGMP?

Answer 15

Activates phosphokinase G

Question 16

In the nitric oxide cGMP pathway in smooth muscle cGMP activates phosphokinase G.

What is the function of PKG

Answer 16

Phosphorylattes down stream target

Question 17

What is the purpose of the nitric oxide cGMP pathway in smooth muscle ?

Answer 17

Leads to smooth muscle relaxation

Prevention of actin and myosin cross bridge leading to smooth muscle relaxation

Question 18

In the absence of oxygen, cells rely on anaerobic metabolism to staisfy their need for ATP. What are the biochemical changes associated with prolonged anaerobic respiration?

Comment on lactate levels and serum pH

(Sizer and Neil)

Answer 18

Increased lactate levels
Serum pH decrease

Question 19

BIOPHYSICS

Answer 19

BIOPHYSICS

Question 20

What is ionizing radiation?

Answer 20

Radiation characterized by its high energy which allows it to remove electrons from atoms causing biological damage.

Question 21

What is found in the nucleus of the atom?

Answer 21

Protons and Neutrons

Question 22

What is found in the outside the nucleus of the atom?

Answer 22

Electrons

Question 23

Ionizing radiation is characterized by its high energy which allows it to remove electrons from atoms causing biological damage.

Is Xray ionizing or non ionizing radiation?

Answer 23

Ionizing radiation

Question 24

Ionizing radiation is characterized by its high energy which allows it to remove electrons from atoms causing biological damage.

Is DEXA ionizing or non ionizing radiation?

Answer 24

Ionizing radiation

Question 25

What does acronym DEXA stands for?

Answer 25

Dual energy Xray Absorptiometry

Question 26

Ionizing radiation is characterized by its high energy which allows it to remove electrons from atoms causing biological damage. Is Iodine 131 ionizing or non ionizing radiation?

Answer 26

Ionizing radiation

Question 27

Ionizing radiation is characterized by its high energy which allows it to remove electrons from atoms causing biological damage. Is CT scan ionizing or non ionizing radiation?

Answer 27

Ionizing radiation

Question 28

Ionizing radiation is characterized by its high energy which allows it to remove electrons from atoms causing biological damage. Is Laser ionizing or non ionizing radiation?

Answer 28

Non Ionizing radiation