Mass Transport In Animals Flashcards
Haemoglobin - Binding of one molecule of oxygen
to haemoglobin makes it easier for a second oxygen
molecule to bind. Explain why (2)
- Binding of first oxygen changes tertiary /
quaternary (structure) of haemoglobin;
Ignore ref. to ‘positive cooperativity’ unqualified
Ignore ref. to named bonds
Accept conformational shift caused - Creates / leads to / uncovers second / another
binding site
OR
Uncovers another iron / Fe / haem group to bind to;
Haemoglobin - Explain how changes in the shape of
haemoglobin result in the S-shaped (sigmoid)
oxyhaemoglobindissociation curve (2)
- First oxygen binds (to Hb) causing change in shape;
- (Shape change of Hb) allows more O2 to bind (easily)
/ greater saturation with O2
OR
Cooperative binding;
Haemoglobin - Haemoglobin is a
protein with a quaternary structure.
Explain the meaning of quaternary structure (1).
(Molecule contains) more than one polypeptide (chain)
Haemoglobin - Describe the advantage of the
Bohr effect during intense exercise. (2)
- Increases dissociation of oxygen;
Accept unloading/ release/reduced affinity for dissociation - For aerobic respiration at the tissues/muscles/cells
OR
Anaerobic respiration delayed at the
tissues/muscles/cells
OR
Less lactate at the tissues/muscles/cells;
Haemoglobin - Describe and explain the effect of increasing carbon dioxide concentration on the dissociation of oxyhaemoglobin (2)
- Increases/more oxygen dissociation/unloading
OR
Deceases haemoglobin’s affinity for O2;
Accept more readily
Accept releases more O2 - (By) decreasing (blood) pH/increasing acidity;
Haemoglobin – why curve shifts left when diving (2)
- High(er) affinity for O2 (than haemoglobin)
OR
Dissociates oxygen less readily
OR
Associates more readily;
Accept holds O2 at lower ppO2 - Allows (aerobic) respiration when diving/at low(er)
pO2
OR
Provides oxygen when haemoglobin unloaded
OR
Delays anaerobic respiration/lactate production;
Haemoglobin –
Animals living at high altitudes shift to left (3)
- high altitudes have a low partial pressure of O2;
- high saturation/affinity of Hb with O2 (at low partial pressure O2);
- sufficient/enough O2 supplied to respiring cells /
tissues;
Haemoglobin – why small animals have
curved to the right (2)
- Mouse haemoglobin/Hb has a lower affinity for
oxygen
OR
For the same pO2 the mouse haemoglobin/Hb is less
saturated
OR
At oxygen concentrations found in tissue
mouse haemoglobin/Hb is less saturated;
For ‘Hb is less saturated’ accept ‘less oxygen will be
bound to Hb’. - More oxygen can be dissociated/released unloaded (for metabolic reactions/respiration);
Accept ‘oxygen
dissociated/released/unloaded more readily/easily/quickly
Haemoglobin – why curve to the right for
more active animals (4)
- Curve to the right so lower affinity / % saturation
(of haemoglobin); - Haemoglobin unloads / dissociates more readily;
- More oxygen to cells / tissues / muscles;
- For greater / more / faster respiration;
Heart & circulation – dissection -
three control measures thestudent must use to
reduce the risks associated with carrying and using a scalpel
- Carry with blade protected / in tray
- Cut away from body;
- Cut onto hard surface;
- Use sharp blade;
- Dispose of used scalpel (blade) as instructed;
Heart & circulation – dissection
Control measures when packing away (2)
- Carry/wash sharp instruments by holding handle
OR
Carry/wash sharp instruments by pointing away (from body)/down;
Accept for ‘instruments’, a suitable named example, eg. scalpel - Disinfect instruments/surfaces;
Accept for ‘instruments’, a suitable named example, eg. scalpel
Accept for ‘disinfect’, sanitise OR use antiseptic - Disinfect hands
OR
Wash hands with soap (and water);
Accept for ‘disinfect’, sanitise OR use antiseptic - Put organ/gloves/paper towels in a (separate)
bag/bin/tray to dispose;
Heart & circulation - Give the pathway a red blood cell takes when travelling in the human circulatory system from a kidney to the lungs. (3)
- Renal vein;
- Vena cava to right atrium;
- Right ventricle to pulmonary artery;
Heart & circulation -
Name the blood vessels that carry blood to the
heart muscle. (1)
Coronary arteries;
Heart & circulation -
Calculate Cardiac Output (1)
Cardiac Output = Stroke Volume x Heart Rate
Heart & circulation –
what causes the semi- lunar valve to close (1)
Because pressure in aorta higher than in ventricle;
Heart & circulation – explain how the atrioventricular valve is closed (2)
- ventricle contracts and volume decreases
- pressure (ventricle) increases so higher than pressure of left atrium;
Heart & circulation -
Explain how an arteriole can reduce the blood flow into capillaries. (2)
- Muscle contracts;
- Constricts/narrows arteriole/lumen;
Heart & circulation -
Artery – Structure and Function (5)
- Elastic tissue to allow stretching/recoil/ smooths out flow of blood/maintains pressure;
- (Elastic tissue) stretches when ventricles contract OR
Recoils when ventricle relaxes; - Muscle for contraction/vasoconstriction;
- Thick wall withstands pressure
- Smooth endothelium reduces friction;
Heart & circulation -
Explain four ways in which the structure
of the aorta is related to its function.
- Elastic tissue to allow stretching / recoil /
smoothes out flow of blood / maintains pressure; - (Elastic tissue) stretches when ventricles contract
OR
Recoils when ventricle relaxes; - Muscle for contraction / vasoconstriction;
- Thick wall withstands pressure
- Smooth endothelium reduces friction;
- Aortic valve / semi-lunar valve prevents backflow.
Heart & circulation Fish – describe type of circulation in fish (2)
- Single circulatory system
2 chambers/1 ventricle1 atrium - One vein carrying blood towards the heart/ One artery carrying blood away
Tissue fluid - Explain how water from tissue fluid is returned to the circulatory system (4)
- (Plasma) proteins remain;
Accept albumin/globulins/fibrinogen for (plasma) protein - (Creates) water potential gradient
OR
Reduces water potential (of blood); - Water moves (to blood) by osmosis;
- Returns (to blood) by lymphatic system;
Tissue fluid - Explain the role of the heart
in the formation of tissue fluid. (2)
- Contraction of ventricle(s) produces high blood /
hydrostatic pressure; - (This) forces water (and some dissolved
substances) out (of blood capillaries);
Tissue fluid - High absorption of salt from the diet can result in a higher than normal concentration of salt in the blood plasma entering capillaries. This can lead to a build-up of tissue fluid. Explain how (4)
- (Higher salt) results in lower water potential of
tissue fluid; - (So) less water returns to capillary by osmosis (at
venule end); - (Higher salt) results in higher blood pressure /
volume; - (So) more fluid pushed / forced out (at arteriole
end) of capillary;
Tissue fluid - High blood pressure
leads to an accumulation of tissue fluid. Explain
how (2)
- High blood pressure = high hydrostatic pressure;
- Increases outward pressure from (arterial) end of
capillary / reduces inward pressure at (venule) end of
capillary; - (So) more tissue fluid formed / less tissue fluid is
reabsorbed.
