11. Oxygen-hemoglobin dissociation curve Flashcards Preview

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Flashcards in 11. Oxygen-hemoglobin dissociation curve Deck (22):
1

Oxygen-hemoglobin dissociation curve - shape and why

sigmoidal shape due to positive cooperativity

2

myoglobin - structure , properties

myoglobin monomeric and thus does not show positive cooperativity

3

Myoglobin -Oxygen-hemoglobin dissociation curve

curves lacks sigmoidal apperance

4

right shift Oxygen-hemoglobin dissociation curve causes

decreased affinity of Hb for O2

5

right shift Oxygen-hemoglobin dissociation curve - purpose

facilates unloading of O2 to tissue

6

Oxygen-hemoglobin dissociation curve with fetal hemoglobin and mechanism

fetal Hb has higher affinity for O2 than adult Hb, so its dissociation curve is shifted left

7

Oxygen-hemoglobin dissociation curve shift factors

1. H+
2. Co2
3. Exercise
4. 2.3 BPG
5. Altitude
6. Temperature
increased---> righ shift
decreased left shift

8

• What is the shape of the oxygen-hemoglobin dissociation curve? Explain

Sigmoidal due to positive cooperativity, as Hb can bind four O2 molecules—O2 binding is easier when more O2 is bound

9

How does the structure of myoglobin affect its function?

It is monomeric and thus has no positive cooperativity as seen in hemoglobin, and it lacks the sigmoidal curve

10

When the oxygen-hemoglobin dissociation curve shifts to the right, what happens to the affinity of hemoglobin for oxygen?

A right shift decreases the affinity of hemoglobin for oxygen

11

When the oxygen-hemoglobin dissociation curve shifts to the right, what happens to the O2 saturation (%) at a PO2 of 50 mmHg?

A right shift decreases oxygen saturation (higher oxygen pressure is required to saturate hemoglobin)

12

A shift of the oxygen-hemoglobin dissociation curve to the right facilitates what process in tissue?

The unloading of oxygen to tissue

13

When the oxygen-hemoglobin dissociation curve shifts to the left, what happens to the affinity of hemoglobin for oxygen?

A left shift increases the affinity of hemoglobin for oxygen

14

Increases in the amount of which six factors cause a right shift of the oxygen-hemoglobin dissociation curve?

Right = ACE BATs right handed (Acid [H+], CO2, Exercise, 2,3-BPG, Altitude, Temperature)

15

Decreases in the amount of which factors cause a left shift of the oxygen-hemoglobin dissociation curve?

Acid (H+), CO2, exercise, 2,3-BPG, altitude, temperature

16

• A fetus's oxygen-hemoglobin dissociation curve is investigated. How does it compare to an adult's oxygen-hemoglobin dissociation curve?

It is shifted to the left (fetal hemoglobin has higher affinity for oxygen than has adult hemoglobin)

17

A patient in shock develops a lactic acidosis. This decrease in pH causes what kind of shift in the oxygen-hemoglobin dissociation curve?

Right shift (due to increased acid [or H+] lowering the pH)

18

A patient's chest is injured and her partial pressure of CO2 is increased. How does this affect her oxygen-hemoglobin dissociation curve?

Shifts it to the right

19

A patient is exercising. What effect would this have on his oxygen-hemoglobin dissociation curve?

A right shift

20

An increase in 2,3-bisphosphoglycerate (2,3-BPG) causes a ____ (left/right) shift in the oxygen-hemoglobin dissociation curve

Right

21

A hiker scales an extremely tall mountain. High altitude induces what change in the oxygen-hemoglobin dissociation curve?

A right shift

22

• A patient develops a fever. An increase in temperature causes what kind of shift in the oxygen-hemoglobin dissociation curve?

A right shift