Mass transport in Animals 3.3.4.1 Flashcards
What is the primary function of haemoglobin?
To transport oxygen from the lungs to the tissues and carbon dioxide from the tissues back to the lungs.
True or False: Haemoglobin is a protein found in red blood cells.
True
How many polypeptide chains make up a haemoglobin molecule?
Four
What are the two types of polypeptide chains found in adult haemoglobin?
Alpha and beta chains
Fill in the blank: Each haemoglobin molecule can bind to ___ oxygen molecules.
Four
What is the name of the iron-containing group in haemoglobin?
Heme group
True or False: The heme group is responsible for the red color of blood.
True
What type of bond allows haemoglobin to change shape when binding to oxygen?
Cooperative binding
What is the significance of the allosteric properties of haemoglobin?
They enhance the efficiency of oxygen transport.
What is the effect of carbon dioxide on haemoglobin’s affinity for oxygen?
Carbon dioxide decreases haemoglobin’s affinity for oxygen.
Define the term ‘oxygen saturation’ in relation to haemoglobin.
The percentage of haemoglobin binding sites occupied by oxygen.
What is the Bohr effect?
The phenomenon where increased carbon dioxide concentration leads to decreased oxygen affinity of haemoglobin.
Multiple choice: Which of the following is NOT a function of haemoglobin? A) Oxygen transport B) Carbon dioxide transport C) Nutrient absorption
C) Nutrient absorption
What structural feature allows haemoglobin to bind oxygen effectively?
The presence of heme groups with iron ions.
True or False: Haemoglobin can also transport nitric oxide.
True
yes
What is the role of 2,3-bisphosphoglycerate (2,3-BPG) in relation to haemoglobin?
It decreases the affinity of haemoglobin for oxygen.
What impact does temperature have on haemoglobin’s function?
Higher temperatures decrease haemoglobin’s affinity for oxygen.
How does pH affect haemoglobin’s oxygen binding?
Lower pH (more acidic) decreases haemoglobin’s affinity for oxygen.
What is the quaternary structure of haemoglobin?
The arrangement of multiple polypeptide subunits into a functional protein.
True or False: Haemoglobin’s structure remains unchanged when it binds to carbon dioxide.
False
What is the relationship between haemoglobin and myoglobin?
Both are oxygen-binding proteins, but myoglobin has a higher affinity for oxygen and is found in muscle tissue.
Fill in the blank: The different forms of haemoglobin, such as fetal haemoglobin, have different ___ for oxygen.
Affinities
What does the term ‘sickle cell haemoglobin’ refer to?
A mutation in the beta chains of haemoglobin that causes red blood cells to assume a sickle shape.
Multiple choice: Which condition can be caused by abnormal haemoglobin? A) Sickle cell disease B) Cystic fibrosis C) Diabetes
A) Sickle cell disease
how many oxygens can bind to each haemoglobin molecule
4
what type of protein is haemoglobin
globular protein
what is meant by the term affinity in terms of haemoglobin
the strength of attraction or binding ability between molecules
haemoglobin has a high affinity to oxygen
what is formed when oxygen binds to haemoglobin
oxyhaemoglobin
what is dissociation
process where red blood cells reach the tissues in the body and oxygen is released from the oxyhaemoglobin
what is partial pressure simply
concentration of a single gas
what is the case if partial pressure of oxygen is high
haemoglobin has high affinity for oxygen and binds to it
what is cooperative binding
change in shape of haemoglobin caused by binding of the first oxygen making the binding of further oxygens easier
what is the case if there is low partial pressure of oxygen in a cell
haemoglobin has low affinity for oxygen so oxygen dissociates from haemoglobin
describe the structure of haemoglobin (4 main points)
globular
water soluble
four polypeptide chains each with one haem group
quaternary structure
3 factors affecting oxygen-haemoglobin binding
-partial pressure/concentration of oxygen
-partial pressure/concentration of carbon dioxide
-saturation of haemoglobin with oxygen
how does partial pressure of oxygen affect oxygen-haemoglobin binding
increasing partial pressure, increases affinity of haemoglobin for oxygen
lowering partial pressure causes haemoglobin to release haemoglobin
what is the name of the partial pressure of carbon dioxide affect on oxygen-haemoglobin binding
Bohr effect
describe the Bohr effect
as partial pressure of carbon dioxide increase, conditions become more acidic and haemoglobin changes shape
affinity for haemoglobin for oxygen decreases, oxygen is released into surrounding tissue
3 reasons why oxygen binds to haemoglobin in the lungs
-partial pressure of oxygen is high
-low concentration of carbon dioxide in the lungs, so high affinity
-positive cooperativity, after first oxygen molecule binds, binding becomes easier
why is oxygen released from haemoglobin in respiring tissues
-partial pressure of oxygen is high
-high concentration of carbon dioxide so affinity decreases
how does carbon dioxide affect the position of an oxyhaemoglobin dissociation curve
curve shift right because affinity for oxygen decreases
how are arteries related to their function
-thick walls to handle high pressure without tearing
-muscular and elastic to control blood flow
how are veins adapted to their function
-thin walls due to lower pressure
-valves to ensure no backflow
-less muscular and elastic tissue as they don’t have to control blood flow
what happens during cardiac diastole
-heart is relaxed
-blood enters the atria, increasing pressure and pushing open atrioventricular valves
-allows blood to flow into the ventricles
-pressure in the heart is lower than in the arteries so semilunar valves remain closed
what happens during atrial systole
-atria contract
-pushing any remaining blood into the ventricles
what happens during ventricular systole
-ventricles contract
-pressure increases closing the atrioventricular valves to prevent backflow and opening semilunar valves
-blood flows into the arteries
where is the sinoatrial node (SAN)
wall of right atrium
where is atrioventricular node (AVN)
between the two atria
define myogenic
the heart’s contraction is initiated from within the muscle itself, rather than by nerve impulses
structure of capillaries and why suited
-walls are one cell thick - short diffusion pathway
-very narrow - can permeate tissues and red blood cells can lie flat against wall and effectively deliver oxygen to tissues
-numerous and highly branched, providing a large surface area
what is tissue fluid?
watery substance containing glucose, amino acids, oxygen ect…
supplies these to cells and removes waste materials
how is tissue fluid formed
blood is pumped through increasingly small vessels
hydrostatic pressure is created which forces fluid out of the capillaries
it bathes the cell and then returns to the capillaries when hydrostatic pressure is low enough
Cardiac output equation
CO = stroke volume x heart rate
