Masss Tramsport

Question 1

Structure of Haemoglobin

Answer 1

-Haemoglobin is a tetra meter consisting of 4 polypeptide chain called globing
-consist of 2 alpha , 141 2 beta chains 146 aa long
-attached to each chain is a haem group

Question 2

Affinity

Answer 2

Chemical attraction

Question 3

Dissociating

Answer 3

Process by which Haemoglobin releases its oxygen

Question 4

Associating

Answer 4

Processes by which Haemoglobin binds with oxygen

Question 5

High affinity

Answer 5

Take up oxygen more easily but release less easily

Question 6

Low affinity

Answer 6

Takeout ocugen less easily but releases more Easily

Question 7

Why Haemoglobin from different species have different affinities for oxygen

Answer 7

Each has slightly different primary structure thus has a different tertiary and quaternary structure. This means they have a different affinity for oxygen.

Question 8

Gas exchange surfaces

Answer 8

High o2 conc
Low co2 conc
High affinity for oxygen
Oxygen is associated

Question 9

Respiring tissues

Answer 9

Low oxygen conc
High carbon dioxide conc
Low affinity for oxygen
Oxygen is disassociated

Question 10

Partial pressure of oxygen

Answer 10

The amount of oxygen that can combine with Haemoglobin is determined by the oxygen concentration
The pressure of a single gas component in a. Mixture of gases it correspond to the total pressure which the single gas component would exert it it alone occupied the whole volume

Question 11

Oxygen dissociation curves

Answer 11

When the po2 falls at first this has little effect on the percentage saturation
As blood passes through the heart and arteries the po2 drops slightly but the Haemoglobin does not lose much oxygen

Question 12

Haemoglobin saturation at high values

Answer 12

Lungs at sea level :pO2 of 100mmhg Haemoglobin is 98% saturated
When the pO2 in the lungs declines below typical sea level values Haemoglobin stil has a high affinity for o2 and remains almost fully saturated

Question 13

Haemoglobin saturation levels at low Po2

Answer 13

At a po2 of 40mm hg Haemoglobin has a lower affinity for oxygen and is

Question 14

Describe how Haemoglobin loads and unloads oxygen in the blood

Answer 14

1)oxygen loads and binds to Haemoglobin in areas of high partial pressure like in the alveoli in the lungs this causes association
2)Haemoglobin has a high affinity for oxygen
3)muscles and tissues have low po2 and lower affinity which causes disassociation and this causes unloading of oxygen

Question 15

How does Haemoglobin transport oxygen from a gas exchange surface to respiring cells

Answer 15

-binding of oxygen molecules to the Haemoglobin molecules
-causes a change in the shape of the hemoglobin molecule, allowing it to pick up more oxygen as it travels through the lungs.
-

Question 16

How are the properties of the Haemoglobin that an organism contains suited to its wat of life

Question 17

Features of transport systems

Answer 17

1)suitable medium to carry materials
2)transport medium is moved over large distances in bulk
3)

Question 18

Open systems

Answer 18

1)blood is pumped by the heart into an aorta which branches into a number of arteries
2)these open into a series of blood spaces
3)blood moves through the tissues under low pressure gradually percolating back into the heart via open ended veins
4)distribution of blood is poorly controlled

Question 19

Closed systems

Answer 19

1)animals with a higher metabolic rate needs fast and efficient delivery of oxygen and glucose to the tissues and removal of carbon dioxide and other waste products from the tissues
2)only a closed system can do this
3)blood is pumped rapidly around the body under high pressure and back ngo the heart

Question 20

myocardium

Answer 20

thick muscular layer of uscle heart wall

Question 21

cardiac muslce

Answer 21

specialised muscle cells of the heart joined by intercalated discs

Question 22

myogeneic

Answer 22

cardiac muscle is self exciting

Question 23

valves

Answer 23

prevent backflow and make heart sounds “lubb” dubb`’

Question 24

at rest heart beat should be

Answer 24

72bpm

Question 25

cardiac output

Answer 25

heart rate x steoke volume

Question 26

cardiac cycle

Answer 26

1 complete beat of heart lasts approx 0.83s

Question 27

3 main stages of cardiac cycle

Answer 27

1)atrual systoel-contraction of atria
2)ventricular systole-contraction of ventricles
3)complete cardiac diastole -relaxation of atria and ventricles

Question 28

Structuvte or xylem

Answer 28

Used to transport water and mineral from roots to leaves
Consiste of tubes for water , fibres for supporting and living parenchyma cells

Question 29

Transport of water through the xylem

Answer 29

-xylem vesselsnrun from root to leaves as continues narrow tubes
-the column of water coheres -does not break adheres to the walls of the xylem vessels

Question 30

Cohesion tension theory

Answer 30

As water is removed from xylem more water molecules are pulled up to replace them thus pulling force is known as transpiration pull
This pull puts the xylem under tension which causes negative pressure called the cohesion tension theory

Question 31

Cohesion

Answer 31

Water molecules sticking together

Question 32

The main way that water passes into the root

Answer 32

Mass flow through interconnecting free spaces in the cellulose cell walls apoplast
Once the water reaches the endodermis it is preventing from conintuing along the Apoplas by casparian strips so much reach the xylem by osmosis

Question 33

Steele

Answer 33

Central cylinder of vascular tissue

Question 34

Casparian strips

Answer 34

A water repellent ,waxy layer surrounding the eperdeemis cells around the Steele

Question 35

Plasmodesmata

Answer 35

Wheeew cytoplasm connects between 2 plant cells

Question 36

Explain the mass flow hypothesis as a mechanism for translocation

Answer 36

1)co transport of h+ions with sucrose into the phloem by companion cells
2)lowers water potential of sieve tubes so water enters by osmosis
3)pressure increases causing mass movement