Transport Exam Questions

Question 1

affinity of haemoglobin

Answer 1

the ability for haemoglobin to attract or bind to oxygen

Question 2

saturation of haemoglobin

Answer 2

when haemoglobin can hold the maximum amount of oxygen it can bind to

Question 3

association of haemoglobin

Answer 3

the binding of oxygen to haemoglobin

Question 4

unloading of haemoglobin

Answer 4

when oxygen unbinds to haemoglobin

Question 5

Describe the processes involved in the absorption and transport of digested lipid molecules from the ileum into lymph vessels.

Answer 5

1.)Micelles contain bile salts and fatty acids/monoglycerides;
2.Make fatty acids more soluble in water
3. Fatty acids are absorbed by diffusion;
4. Triglycerides reformed in cells
5. Vesicles move to cell membrane;

Question 6

Describe the role of micelles in the absorption of fats into the cells lining of the ileum

Answer 6

Micelles include bile salts and fatty acids;

Make the fatty acids more soluble in water;

carry fatty acids to cell lining of the ileum

Maintain higher concentration of fatty acids to cell lining of the ileum);

Question 7

Describe the role of enzymes in the digestion of proteins in a mammal.

Answer 7

Reference to) hydrolysis of peptide bonds;

Endopeptidase act in the middle of protein

Exopeptidases act at end of protein/polypeptide

Dipeptidase acts on dipeptide/between two amino acids

Question 8

What does the Golgi apparatus for the absorption of lipids

Answer 8

2. processes triglycerides;
3. Combines triglycerides with proteins;
4. exocytosis takes place

Question 9

Cells lining the ileum of mammals absorb glucose by co-transport with sodium ions. Explain how

Answer 9

1.)Sodium ions actively transported from ileum cells to blood
2.)forms diffusion gradient for sodium and glucose to enter cells from gut
3. Glucose enters by facilitated diffusion with sodium ions;

Question 10

Describe and explain one feature of the alveolar epithelium that makes the epithelium well adapted as a surface for gas exchange

Answer 10

1.)Single layer of cells;
Accept ‘one cell thick’
2. Reduces diffusion distance/pathway;

Question 11

Suggest and explain how a reduced tidal volume affects the exchange of carbon dioxide between the blood and the alveoli

Answer 11

1.)Less carbon dioxide exhaled/moves out

2.) So) reduced diffusion (between blood and alveoli);

3. Less movement of carbon dioxide out of blood

Question 12

Explain how the counter-current principle allows efficient oxygen uptake in the fish gas exchange system

Answer 12

1.)Blood and water flow in opposite directions;
2.)concentration gradient maintained along the length of lamella/filament

Question 13

Describe and explain the mechanism that causes lungs to fill with air.

Answer 13

1.)Diaphragm muscle contracts and external intercostal muscles relax
2. Causes volume increase and pressure decrease
3. Air moves down a pressure gradient

Question 14

explain why plants
grown in soil with very little water grow only slowly

Answer 14

1.)Stomata close;
2.)Less carbon dioxide (uptake) for less photosynthesis/glucose production

Question 15

a) Describe the pathway taken by an oxygen molecule from an alveolus to the blood

Answer 15

1.first Across the alveolar epithelium;

2.then epithelium of capillary;

Question 16

Explain how one feature of an alveolus allows efficient gas exchange to occur.

Answer 16

The alveolar epithelium is one cell thick

Creates a short diffusion pathway

Question 17

Explain three ways in which an insect’s tracheal system is adapted for efficient gas exchange

Answer 17

1.Tracheoles have thin walls so short diffusion distance to cells;

2. large number of tracheoles so short diffusion distance to cells;
3. large number of tracheoles so large surface
   area
4. Tracheae provide tubes full of air so fast diffusion into insect
   tissues
5. Fluid in the end of the tracheoles that moves out into tissues
   during exercise

so faster diffusion through the air to the gas exchange surface;

Question 18

a) Explain two ways in which the structure of fish gills is adapted for efficient
gas exchange

Answer 18

1.)Many lamellae / filaments so large surface area;

2. Thin (surface) so short diffusion pathway;

Question 19

Explain how the counter current mechanism in fish gills ensures the maximum amount of the oxygen passes into the blood flowing through the gills

Answer 19

1.)Water and blood flow in opposite directions;
2. Blood always passing water with a higher oxygen concentration;
3. Diffusion gradient maintained throughout length of filament

Question 20

Explain why death of alveolar epithelium cells reduces gas exchange in human lungs.

Answer 20

Reduced surface area

Increased diffusion pathways
Reduced rate of gas exchange

Question 21

Give the pathway a red blood cell takes when travelling in the human circulatory system from a kidney to the lungs.

Answer 21

1.)Renal vein
2.)Vena cava to right atrium;
3. Right ventricle to pulmonary artery;

Question 22

Tissue fluid is formed from blood at the arteriole end of a capillary bed.
Explain how water from tissue fluid is returned to the circulatory system.

Answer 22

1.Plasma proteins remain;
2. Creates water potential
3. Water moves to blood by osmosis;
4. Returns to blood by lymphatic system;

Question 23

Explain how an arteriole can reduce the blood flow into capillaries.

Answer 23

Muscle contracts;
Constricts and narrows arteriole lumen

Question 24

Describe two precautions the student should take when clearing away after
the dissection

Answer 24

Disinfect instruments/surfaces;

Carry sharp instruments by the handle

Question 25

Describe and explain the effect of increasing carbon dioxide concentration on the dissociation of oxyhaemoglobin

Answer 25

Increases oxygen unloading
(By) increasing acidity in the blood

Question 26

Explain how left artmaintains a unidirectional flow of blood.

Answer 26

Pressure in (left) atrium is higher than in ventricle/B causing valve to open;

Pressure in (left) ventricle/B is higher than in atrium causing valve to close

Question 27

Binding of one molecule of oxygen to haemoglobin makes it easier for a second oxygen molecule to bind

Answer 27

Binding of first oxygen changes tertiary / quaternary (structure) of haemoglobin
uncovers another binding site

Question 28

Explain how changes in the shape of haemoglobin result in the S-shaped (sigmoid) oxyhaemoglobin dissociation curve for HbA.

Answer 28

1.)First oxygen binds (to Hb) causing change in shape;

2.(Shape change of Hb) allows more O2 to bind (easily