Haemoglobin

Question 1

Why can’t large organisms use diffusion for gas exchange?

Answer 1

-they have a small SA:V
-simple diffusion is not sufficient enough to meet the organisms Oxygen demands
-alternative method required to transport oxygen to tissues

Question 2

How do organisms solve the problem of not being able to have oxygen diffusion into their bodies?

Answer 2

-they circulate blood around their bodies to carry oxygen to respiring tissues

Question 3

Why can’t oxygen just dissolve into the blood?

Answer 3

Oxygen has a low solubility in aqueous solutions (such as water)

Question 4

Structure of haemoglobin:

Answer 4

-complex protein quaternary structure
-composed of four polypeptides
-each containing a prosthetic haem group (Fe2+ containing group)

Question 5

Haemoglobin has an ______ to oxygen

Answer 5

Affinity

Question 6

What is affinity?

Answer 6

Chemical attraction

Question 7

How many oxygen molecules can one haemoglobin molecule combine with?

Answer 7

4

Question 8

How much molecules of haemoglobin are in one red blood cell?

Answer 8

300 million

Question 9

How is haemoglobin efficeint at transporting oxygen?

Answer 9

-readily associates at the lungs
-and dissociates at respiring tissues

Question 10

The uptake of oxygen by haemoglobin is a _____ reaction

Answer 10

Reversible

Question 11

What does oxygen and haemoglobin combining form..?

Answer 11

Oxyhaemoglobin

Question 12

The amount of oxygen combined is described in terms of…

Answer 12

percentage saturation of the haemoglobin

Question 13

formula for calculating the percentage saturation of haemoglobin with oxygen

Answer 13

Percentage saturation =

oxygenated haemoglobin
————————————- x100%
maximum saturation

Question 14

partial pressure of oxygen

Answer 14

The proportion of oxygen in a mixture of gases or solution

Question 15

What happens when ocyhaemoglobin moves to an area of low oxygen concentration?

Answer 15

Oxygen is unloaded to the surroundings

Question 16

An oxygen dissociation curve is what shape?

Answer 16

S shaped and described as a sigmoid curve

Question 17

How does the binding of one oxygen molecule make it easier for other oxygen molecules to bind to haemoglobin?

Answer 17

-the binding of the first oxygen molecule alters the tertiary structure of the haemoglobin molecule
-this exposes the second and third binding sites
-which makes it easier for the second and third oxygen molecules to bind and load
» referred to as the cooperative nature of oxygen loading

Question 18

Haemoglobin has a higher affinity for oxygen at..

Answer 18

a high partial pressure of oxygen

Question 19

The partial pressure of oxygen is h