mass transport in humans

Question 1

What are haemoglobins?

Answer 1

A group of chemically similar molecules found in many different organisms

Haemoglobins are essential for oxygen transport in various life forms.

Question 2

What type of protein is haemoglobin?

Answer 2

A protein with a quaternary structure

This means it is composed of more than one polypeptide chain.

Question 3

What is the primary role of haemoglobin?

Answer 3

Transport of oxygen in red blood cells

Haemoglobin carries oxygen from the lungs to body tissues.

Question 4

What is the oxyhaemoglobin dissociation curve?

Answer 4

A graph that shows the loading, transport, and unloading of oxygen by haemoglobin

It illustrates how haemoglobin’s affinity for oxygen changes with different conditions.

Question 5

What does cooperative binding mean in relation to haemoglobin?

Answer 5

The change in shape of haemoglobin upon binding the first oxygen makes it easier for additional oxygens to bind

This phenomenon enhances oxygen loading efficiency.

Question 6

What is the Bohr effect?

Answer 6

The effect of carbon dioxide concentration on the dissociation of oxyhaemoglobin

Increased carbon dioxide lowers pH, promoting oxygen release from haemoglobin.

Question 7

How do different animals adapt their haemoglobin?

Answer 7

By possessing different types of haemoglobin with varying oxygen transport properties

Adaptations help animals survive in their specific environments.

Question 8

What is the composition of human haemoglobin?

Answer 8

Made up of four polypeptide chains, each containing a haem group with an iron ion

The iron ion is crucial for oxygen binding, giving haemoglobin its red color.

Question 9

What occurs in the lungs regarding haemoglobin and oxygen?

Answer 9

Oxygen joins to haemoglobin to form oxyhaemoglobin in a reversible reaction

This process is essential for effective oxygen transport to tissues.

Question 10

Define the terms ‘loading’ and ‘unloading’ in the context of haemoglobin.

Answer 10

‘Loading’ refers to the binding of oxygen to haemoglobin; ‘unloading’ refers to the release of oxygen from oxyhaemoglobin

These processes are critical for oxygen delivery to cells.

Question 11

What does ‘affinity for oxygen’ mean?

Answer 11

The tendency of a molecule to bind with oxygen

Haemoglobin’s affinity varies with conditions such as oxygen concentration.

Question 12

What is the relationship between partial pressure of oxygen (pO2) and haemoglobin’s affinity for oxygen?

Answer 12

As pO2 increases, haemoglobin’s affinity for oxygen also increases

This allows for efficient oxygen loading in the lungs.

Question 13

What happens to oxygen during cellular respiration?

Answer 13

Cells deliver oxyhaemoglobin to tissues, where oxygen is unloaded

This process is vital for cellular metabolism.

Question 14

Fill in the blank: Haemoglobin can carry _______ oxygen molecules.

Answer 14

four

Each haemoglobin molecule has the capacity to bind four molecules of oxygen.

Question 15

True or False: Haemoglobin is found only in vertebrates.

Answer 15

False

Haemoglobin is also found in earthworms, some insects, plants, and bacteria.

Question 16

What is the primary function of haemoglobin?

Answer 16

Transport oxygen around the body

Haemoglobin is a protein found in red blood cells that binds to oxygen for transport.

Question 17

What happens to haemoglobin in the lungs?

Answer 17

Haemoglobin loads oxygen due to high oxygen concentration and high affinity

The high partial pressure of oxygen (pO₂) in the lungs allows haemoglobin to bind effectively with oxygen.

Question 18

What occurs in respiring tissues regarding haemoglobin?

Answer 18

Haemoglobin unloads oxygen due to low oxygen concentration and low affinity

In tissues where oxygen is consumed, the partial pressure of oxygen is lower, leading to oxygen release.

Question 19

What does the oxygen dissociation curve represent?

Answer 19

It shows how saturated the haemoglobin is with oxygen at any given partial pressure

The curve illustrates the relationship between pO₂ and the percentage saturation of haemoglobin.

Question 20

What is the shape of the oxygen dissociation curve?

Answer 20

S-shaped

This shape indicates varying affinity of haemoglobin for oxygen based on saturation levels.

Question 21

At what pO₂ level does haemoglobin have a high affinity for oxygen?

Answer 21

Where pO₂ is high, such as in the lungs

This results in high saturation of haemoglobin with oxygen.

Question 22

At what pO₂ level does haemoglobin have a low affinity for oxygen?

Answer 22

Where pO₂ is low, such as in respiring tissues

This results in low saturation of haemoglobin with oxygen.

Question 23

What is the significance of 100% saturation of haemoglobin?

Answer 23

Every haemoglobin molecule is carrying the maximum of 4 molecules of oxygen

This indicates optimal oxygen transport capacity.

Question 24

What effect does saturation of haemoglobin have on its affinity for oxygen?

Answer 24

As haemoglobin becomes more saturated, it becomes harder for additional oxygen molecules to join

This results in the characteristic S-shape of the dissociation curve.

Question 25

What does a steep region on the dissociation curve indicate?

Answer 25

A small change in pO₂ causes a big change in the amount of oxygen carried by haemoglobin ## Footnote This indicates high sensitivity of haemoglobin to oxygen levels in that range.

Question 26

What does 0% saturation mean for haemoglobin?

Answer 26

None of the haemoglobin molecules are carrying any oxygen ## Footnote This indicates a complete lack of oxygen binding.

Question 27

What is kPa?

Answer 27

A unit used to measure pressure ## Footnote kPa stands for kilopascal, which is commonly used in scientific contexts.

Question 28

What is the word equation for respiration?

Answer 28

glucose + oxygen → carbon dioxide + water + energy

Question 29

What does it indicate if a dissociation curve is further left?

Answer 29

Higher haemoglobin's affinity for oxygen

Question 30

What effect describes the release of more oxygen in response to increased carbon dioxide concentration?

Answer 30

The Bohr effect

Question 31

In environments with low oxygen concentration, what happens to the dissociation curve?

Answer 31

Shifts to the left

Question 32

In environments with high respiration rates, what happens to the dissociation curve?

Answer 32

Shifts to the right

Question 33

What factor influences the type of haemoglobin an organism has?

Answer 33

Where they live, how active they are, and their size

Question 34

How does the affinity for oxygen in haemoglobin of organisms in low oxygen environments compare to human haemoglobin?

Answer 34

Higher affinity for oxygen

Question 35

What is an example of an organism that lives in low oxygen environments?

Answer 35

Lugworm

Question 36

What characteristic does the haemoglobin of a hawk have due to its high activity levels?

Answer 36

Lower affinity for oxygen

Question 37

What do small mammals tend to have in comparison to larger mammals regarding oxygen transport?

Answer 37

Higher surface area to volume ratio

Question 38

True or False: The dissociation curve of a rat's haemoglobin is to the right of human haemoglobin.

Answer 38

False

Question 39

Fill in the blank: Organisms that are very active and have a high oxygen demand have haemoglobin with a _______.

Answer 39

Lower affinity for oxygen

Question 40

What is the primary purpose of haemoglobin in low oxygen environments?

Answer 40

To load as much oxygen as possible

Question 41

What is the significance of the dissociation curve for haemoglobin?

Answer 41

It indicates how readily haemoglobin releases oxygen

Question 42

What does a higher saturation of haemoglobin with oxygen indicate?

Answer 42

More oxygen is being loaded

Question 43

What is the relationship between pCO2 and oxygen unloading?

Answer 43

Higher pCO2 levels increase the rate at which oxygen is unloaded from haemoglobin ## Footnote This is due to the Bohr effect, where increased carbon dioxide concentration lowers the affinity of haemoglobin for oxygen.

Question 44

What is the shape of the oxygen dissociation curve for haemoglobin?

Answer 44

The curve is sigmoidal (S-shaped) ## Footnote This shape indicates cooperative binding of oxygen molecules to haemoglobin.

Question 45

How does the affinity of haemoglobin for oxygen vary among different animals?

Answer 45

Different animals have varying affinities for oxygen based on their environmental oxygen levels and metabolic demands ## Footnote For instance, a hawk has a lower affinity for oxygen to unload it quickly.

Question 46

What is the significance of a high respiratory rate in hawks?

Answer 46

Hawks have a high respiratory rate to meet their high oxygen demand ## Footnote This is necessary for their active lifestyle and metabolic needs.

Question 47

What does a higher surface area to volume ratio indicate in small animals like rats?

Answer 47

A higher surface area to volume ratio leads to a greater oxygen demand ## Footnote This necessitates their haemoglobin to unload oxygen easily.

Question 48

Fill in the blank: The _______ is the rate at which energy is used.

Answer 48

metabolic rate

Question 49

True or False: A higher metabolic rate leads to a lower respiration rate.

Answer 49

False ## Footnote A higher metabolic rate leads to a higher respiration rate and consequently a higher oxygen demand.

Question 50

What is the process to read values from a dissociation curve?

Answer 50

1. Locate the desired pO2 on the x-axis 2. Draw a line up to the curve 3. Draw a line across to the y-axis ## Footnote This process allows you to determine the percentage saturation of haemoglobin with oxygen.

Question 51

At a pO2 of 6 kPa, what are the saturation levels for Animal A and Animal B?

Answer 51

Animal A: 84% Animal B: 60% ## Footnote The difference in saturation is 24%.

Question 52

Why is it important to be careful when interpreting graphs in biology exams?

Answer 52

Graphs often require specific calculations or interpretations of data ## Footnote Accurate readings and understanding of units are crucial for correct answers.