Transport In Plants And Animals

Question 1

Loading/association def

Answer 1

The process by which haemoglobin binds with oxygen (in the lungs)

Question 2

Unloading/associating

Answer 2

The process by which haemoglobin releases its oxygen (in the tissues)

Question 3

Primary structure of haemoglobin molecules

Answer 3

A sequence of amino acid’s in the four polypeptide chains

Question 4

Secondary structure of haemoglobin molecules

Answer 4

Each of the polypeptide chains are coiled into helix

Question 5

Tertiary structure of haemoglobin molecules

Answer 5

Each polypeptide chain is folded into a precise shape which is important for its ability to carry oxygen

Question 6

Quaternary structure of haemoglobin molecules

Answer 6

All four polypeptides are linked together to form an almost spherical molecule. Each polypeptide is associated with the haem group which contains Fe^2+ ions (ferrous). Fe^2+ ions can combine a single oxygen molecule making a total of four molecules carried around by a single haemoglobin molecule

Question 7

What does decreased affinity for oxygen mean?

Answer 7

It’s more difficult for hemoglobin to bind to oxygen (requiring a higher partial pressure of oxygen to achieve the same oxygen saturation), but it makes it easier for the hemoglobin to release oxygen bound to it

Question 8

What affects haemoglobins affinity for oxygen?

Answer 8

Partial pressure. pH. Concentration of CO2 and O2. Temperature

Question 9

How does haemoglobin officially transport oxygen?

Answer 9

It readily associate with oxygen at the surface where gas exchange takes place. It readily dissociates oxygen at those tissues requiring it.

Question 10

Affinity def

Answer 10

Chemical attraction

Question 11

Where and in what conditions is oxygen associated?

Answer 11

Gas exchange surfaces and oxygen concentration is high, carbon dioxide concentration is low and the affinity of haemoglobin for oxygen is high

Question 12

Where and in what conditions is oxygen dissociated?

Answer 12

Respiring tissues with low oxygen concentration, high carbon dioxide concentrations and affinity of haemoglobin for oxygen is low

Question 13

Oxygen dissociation curve def

Answer 13

A graph of the relationship between the saturation of haemoglobin with oxygen in the partial pressure of oxygen

Question 14

The further left to the curve in an oxygen dissociation curve…

Answer 14

The greater the affinity of haemoglobin for oxygen so it loads oxygen readily and unloads less easily

Question 15

The further right to the curve in an oxygen dissociation curve…

Answer 15

The lower the affinity of haemoglobin for oxygen so it loads oxygen less readily but unloads it more easily

Question 16

Double circulatory system def

Answer 16

Blood passes twice to the heart for a complete circuit of the body

Question 17

Closed circulatory system def

Answer 17

Blood is confined to vessels in the body

Question 18

Atrium

Answer 18

Thin-walled and elastic and it stretches as it collects blood

Question 19

Ventricle

Answer 19

Has a thicker muscular wall as it has to contract strongly to pump blood some distance either to the lungs for the rest of the body

Question 20

Bicuspid valve

Answer 20

Left atrioventricular (between left atrium and left ventricle) to prevent backflow of blood

Question 21

Tricuspid valve

Answer 21

Right atrioventricular (between right atrium and right ventricle) to prevent backflow of blood

Question 22

Diastole

Answer 22

Relaxation of the heart

Question 23

Systole

Answer 23

Contraction of the heart

Question 24

Semi-lunar valves

Answer 24

In the aorta and pulmonary artery to prevent backflow of blood into the ventricles

Question 25

Pocket valves

Answer 25

In veins

Question 26

Cardiac ouput

Answer 26

Heart rate x stroke volume

Question 27

Heart rate

Answer 27

How many beats per minute

Question 28

Stroke volume

Answer 28

Volume of blood pumped out per beat

Question 29

Transport of water in plants

Answer 29

Transpiration through the xylem

Question 30

Transport of sugars in plants

Answer 30

Translocation through the phloem

Question 31

Positive cooperativity

Answer 31

When one oxygen joining onto a subunit on a haemoglobin molecule induces other oxygen molecules to bind

Question 32

Why does the oxygen dissociation curve flatten at high partial pressures?

Answer 32

There is a low likelihood that the oxygen will bind to the haemoglobin as most of the subunits are already occupied

Question 33

Why does carbon dioxide affect dissociation of oxygen from haemoglobin?

Answer 33

Dissolved CO2 is acidic and the low pH changes haemoglobin’s shape