Mass Transport In Animals

Question 1

What in a haem group allows it to bind to oxygen

Answer 1

The iron ion

Question 2

How many polypeptide chains are in a haemoglobin molecule

Answer 2

4

Question 3

How many molecules of oxygen can a single haemoglobin molecule carry

Answer 3

4

Question 4

When the atria contract what happens

Answer 4

Decreases volume and increases pressure of blood pushing blood out of atria into ventricles quickly

Question 5

In the atrial systole the atria contract causing the volume of the atria to

Answer 5

Decrease

Question 6

What happens at the end of atrial systole

Answer 6

Ventricles fill with blood

Question 7

What happens when the pressure in the ventricles is greater than the pressure in the atriums

Answer 7

The atrioventricular valves close to prevent the back flow of blood into the atria

Question 8

What happens when pressure in the ventricles is greater than pressure in the blood pressure

Answer 8

The semi lunar valves open allowing blood to be pushed out of the heart

Question 9

What happens in ventricular systole

Answer 9

Ventricles contract

Question 10

What happens when blood leaves the ventricles

Answer 10

The pressure in the ventricles decreases and the pressure in the blood vessels increases
Causing the semi lunar valve to close preventing back flow of blood into the ventricles

Question 11

What blood vessel does blood enter the heart through

Answer 11

Vena cava

Question 12

What is positive cooperativity

Answer 12

Binding of the first molecule makes binding of the second easier so the gradient of the curve steepens

Question 13

What does haemoglobin affinity for oxygen depend on

Answer 13

The partial pressure of oxygen
Haemoglobin saturation
The partial pressure of carbon dioxide

Question 14

What is partial pressure of a gas

Answer 14

A measure of concentration of that gas in a mixture of gases or in a liquid

Question 15

What does a higher concentration of oxygen mean for partial pressure

Answer 15

Higher partial pressure

Question 16

Where will haemoglobin have a higher affinity for oxygen

Answer 16

In oxygen rich areas like the lungs where there is high p02 promoting oxygen loading

Question 17

Where will haemoglobin have a lower affinity for o2

Answer 17

In oxygen starved areas like respiring tissues where there is low po2 promoting oxygen unloading

Question 18

What happens as saturation for oxygen increases

Answer 18

It becomes harder for the final oxygen molecule to bind

Question 19

What happens to haemoglobin when po2 is high

Answer 19

Haemoglobin has a higher affinity for oxygen

Question 20

What happens to oxygen when carbon dioxide partial pressure is high

Answer 20

O2 dissociates from haemoglobin more easily allowing more o2 to be unloaded to cells during intense activity

Question 21

What happens to blood pH when there is an increase in carbon dioxide production

Answer 21

Leads to a decrease in blood pH as it reacts with water to form carbonic acid

Question 22

What is the Bohr efefct

Answer 22

Describes how changes in the concentration of co2 and pH affects the ability of haemoglobin to bind and release oxygen

Question 23

Which way does the curve shift if the animal has a high metabolic rate/high sa;v

Answer 23

Right a higher metabolic rate =more respiration=greater 02 demand

Question 24

What is cardiac output

Answer 24

Volume of blood pumped by a ventricle in 1 minute

Question 25

What is heart rate

Answer 25

Number of times the ventricles contract in 1 minute

Question 26

What is ur stroke volume

Answer 26

Volume of blood pumped out at each beat

Question 27

How is the higher blood pressure produced in the left ventricle

Answer 27

Stronger contractions

Question 28

Some babies are born with a hole between their left and right ventricles why are they unable to get enough oxygen to their tissues

Answer 28

Blood flows from the left ventricle to the right ventricle missing oxygenated and deoxygenated blood So a lower volume of oxygenated blood leaves the left ventricle

Question 29

Explain how the heart muscles and the heart valves maintain a one-way flow of blood from the left atrium to the aorta

Answer 29

SAN sends wave of electrical activity across atria causing atrial contraction Non-conducting tissues prevents immediate contraction of ventricles / preventing impulses reaching ventricles AVN delays impulse whilst blood leaves atria / ventricles fill AVN sends wave of electrical activity Causing ventricles to contract form the bottom up

Question 30

Which chamber does pressure reach the highest value

Answer 30

Left ventricle

Question 31

Explain how the structure of this chamber causes higher pressure

Answer 31

Thicker muscle

Question 32

An athlete had the same cardiac output but a lower resting heart rate than before explain this change

Answer 32

Increase in the size and strength of the heart muscle Increased stroke volume

Question 34

Explain how the shape of an RBC allows it to take up a large amount of o2 in a short time

Answer 34

Flat and thin so provides a short diffusion pathway for oxygen

Question 35

Explain how oxygen in an RBC is made available for respiration in active tissues

Answer 35

Low ph due to increased co2 Increased respiration so increased dissociation of haemoglobin Oxygen diffuses from RBC to tissues

Question 36

One use of amino acids after hb is broken down

Answer 36

Protein synthesis

Question 37

Advantage of the difference in position of the dissociation curve during exercise

Answer 37

Haemoglobin has a lower affinity of oxygen allowing oxygen to be unloaded to respiring tissues quicker More o2 for respiration

Question 38

Explain what causes pH to be reduces from 7.4 to 7.2 in tissue

Answer 38

Aerobic respiration will produce carbon dioxide Carbon dioxide is dissolved in blood to form carbonic acid Increases hydrogen ion concentration

Question 40

Why do multicellular animals require a transport system

Answer 40

They have a low SA:V and cannot rely on diffusion to supply all their cells and tissues with substances they need Or to remove waste products such as co2 and urea because diffusion distance is too long

Question 41

Why is a closed , double circulatory system more efficient

Answer 41

It increases pressure and therefore speeds up delivery of oxygenated blood to tissues