Topic 7: Mass transport Flashcards
Briefly describe the diff levels of protein structure
- Primary structure - sequence of amino acids
- Secondary structure - local motifs held by hydrogen bonding(alpha helices and b pleated sheets)
- Tertiary structure - 3D structure, held by hydrogen bonding, ionic bonds, disulfide bridges, covalent bonds
- Quaternary structure - multiple polypeptide chains bonded together by hydrogen bonds, ionic bonds, covalent bonds
What kind of structure do haemoglobins have?
Quaternary structure with 4 polypeptide chains
What do haemoglobins consist of?
Four polypeptide chains, each with a heme group and iron at the centre
How many oxygens can haemoglobin carry at any one time
4
At what kind of partial pressures does myoglobin bind at
Low partial pressues
What is myoglobin
A related heme protien that acts as an oxygen binding protien
Where do you find Myoglobin?
In muscle tissues
What does Myoglobin serve as
It serves as a site for intracellular oxygen storage, binding oxygen in very low partial pressues.
What is “affinity of haemoglobin for oxygen”
The ability of haemoglobin to attract or bind to oxygen
What is “saturation of haemoglobin with oxygen”
When haemolgobin is holding the maximum amount of oxygen that it can bind to
What is “loading/association of haemoglobin”
The binding of oxygen to haemoglobin
What is “unloading/dissociation of haemoglobin”
When oxygen detatched or unbinds with haemoglobin
Where is oxygen loaded/unloaded
(give examples aswell)
Loaded - high partial pressure of oxygen (alveoli)
Unloaded - low partial pressure of oxygen (resporing tissues)
What is the affinity of haemoglobin like at low partial pressures
Low affinity to oxygen, unloads
What is the haemoglobin like at high partial pressues
High partial pressures = fully saturated hameoglobin, loading
What happens when the first oxygen has bonded to the haemoglobin
a slight conformational change occurs in the haemoglobin
Why does the haemoglobin undergo a conformational change?
I then becomes easier for the other 3 oxygens to bind to the haemoglobin
What is cooperative binding
When the haemoglobin undergoes a conformational change to allow oxygen to easily bind to it.
What is the Bohr Effect?
When a high concentration of CO2 cuses the dissociation curve to shift to the right
Explain the Bohr Effect
- When there is CO2 and H2O, you will form carbonic acid
- Which has an acidic, lower pH
- The lower pH causes the slight conformational change in the haemoglobin
- Which decreases its affinity for oxygen
- Shifting the curve to the right
Why is haemoglobin being able to change its affinity advantageous to organisms
They can adapt to their environment, for example in an environment with more/less CO2 present, mammals with ater metabolism etc.
Where does the foetal haemoglobin dissociation curve shift?
Shifts to the left
Explain the shift of disocciation curve, for foetal haemoglobin
- higher affinity for O2
- shifts to the left for given partial pressure
- needs to grab as much oxygen from mothers blood (through placenta) as possible
Where does the dissociation curve shift to for Llamas
Shifts to the left
Explain the shift for the dissociation curve of Llamas
- Llamas live at high altitudes
- Need more oxygen, higher affinity
- shifts to left for given partial pressure
Where does the dissociation curve for doves shift to?
(and small mammals)
Shifts to the right
Explain the dissociation curve shift for doves
- small mammals have faster metabolism
- need more O2 for respiration for contracting muscles
- unloading oxygen more, lower affinity for oxygen
- shifts to the right for partial pressure
Where does the dissociation curve for worms shift?
Shifts to the right
Explain the dissociation curve for worms
- underground is low partial pressure
- need haemoglobin with higher affinity for O2
- to obtain as much oxygen as possible
What does it mean by a double, closed, circulatory system
- Closed, the blood is in vessels
- Double, blood is passed twice through the heart
Why does blood flow through the lungs at a lower pressure
- To prevent damage to the capillaries
- To reduce speed, and therefore maximise time for gas exchange
Why is it important for oxygenated blood to flow to the body at high pressures
- To ensure it reaches all respiring tissues
What do the coronary arteries do
Deliver oxygenated blood to the heart msucle
What blood vessels are attatched to the Heart
- Vena Cava
- Aorta
- Pulmonary Artery
- Pulmonary Vein
What blood vessels are attatched to the Lungs
- Pulmonary Artery
- Pulmonary Vein
What are the blood vessels attatched to the Kidneys
- Renal Artery
- Renal Vein
Name and explain two properties of the Cardiac Muscle
(Heart Muscle)
- Myogenic (contracts withough hormonal/nervous stimulation)
- Never fatigues (as long as supplied with oxygen)
What do you call it when the coronary arteires become blocked and no longer recieve oxygen
Myocardial infarction (heart attack)
Compare Atria vs Ventricles
- Atria
Thinner muscular walls, elastic walls that stretch when blood enters - Ventricles
Thicker msucular walls
High pressre to push blood further distances
Which ventricle has thicker walls and why
Left ventricle is thicker, because needs to pump blood at higher pressure all around the body
What does the aorta do
Carries oxygenated blood from left ventricle to the rest of the body
What does the pulmonary vein do
Carries deoxygenated blood from right ventricle to the lungs to become oxygenated
Where do you find semi-lunar valves
Aorta and Pulmonary artery
Where do you find atrioventricular valves
Between atria and ventricles
What are the two atrioventricular valves
Bicuspid (left side)
Tricuspid (right side)
How do valves work
Higher pressure behind the valve opens them, higher pressure behind the valve closes them.
This prevents backflow
What does the septum do
Separates left and right sides, separates oxygenated/deoxygenated blood, therefore maintaining concentration gradient, allowing diffusion at respiring cells
Name the three stages of the cardiac cycle
Diastole (relaxing)
Atrial Systole (contracting)
Ventricular Systole (contracting)
Explain Cardiac cycle
- Diastole - atria ventricle relax and fill with blood (increases pressure in atria)
- Atrial Systole - Atria muscles contract, decreasing volume increasing pressure, opens the atrioventricular valves
- Ventricular Systole - Ventricle muslces contract, decrease volume increase pressure, closes atriaventricular valves, opens semi-lunar valves, blood pushed into aorta and pulmonary artery
How do you work out cardiac output
Cardiac output = heart rate x stroke volume(dm3)
When do the valves open
- Atrioventricular - open with higher pressure in atria than ventricles
- Semi-Lunar - open when higher pressure in ventricles than arteries
What do capillaries connect
Connect arterioles to veins
2 reasons that veins are thin
- Low pressure means that they wont burst
- Easily flattened, helps blood flow up to the heart
What is tissue fluid
Fluid bathing all the cells, contains, water glucose, amino acids, ions, fatty acids and oxygen.
Explain ultrafiltration
- Capillaries have small gaps between them to force out liquid
- Blood enters capillaries from arterioles, smaller diameter = higher hydrostatic pressure
- Forces glucose, water, amino acids, fatty acids, ions, oxygen out
- = ultrafiltration
Describe re-absorption after ultrafiltration
- large moelcules left in fluid = low water potential
- water moves back in capillaries via osmosis
What happens to the liquid not reabsorped after ultrafiltration\?
Tissue fluid absorped into lymphatic system, drains back to the bloodstream by the heart
Where do you find lymph vessels
surrounding blood vessels
How does light intensity affect rate of transpiration
- More light, mor eopen stomata, larger sa for evaporation
- = more transpiration
How does temperature affect rate of transpiration
- More heat, more KE, faster moving molecules more evaporation
How does humidity affect rate of transpiration
- More water vapour in air, increases water potential outside the leaf, reducing water potential gradient, therefore less evaporation
How does wind affect rate of transpiration
- More wind, blows away humidity, maintains conc. gradient, more transpiration
What are the three aspects of Cohesion-Tension theory
- Cohesion
- Capillary action
- Root pressure
Explain cohesion of water
Water is dipolar, forms hydrogen bonds, creating cohesion and stickiness, allowing water to travel as a continuouse column up through the xylem
Explain Capillary action (adhesion)
Water can also stick to other molecules, like the xylem walls, travelling up them.
Thinner tube = more capillary action
Explain root pressure
- Water moves into roots, increased volume means increased pressure, pushing the water up through the root
Explain fully, cohesion tension theory water movement
- Water evaporates cos of transpiration, low water potential on leaves
- More water pulled up thr xylem
- Hydrogen bonds make the water cohesive, water adheres to walls of the thin xylem, pulling more water up as a constant cokumn
- As it is pulled up, it creates tension, causing the xylem walls to become narrower, enhancing the cpillary action
Define translocation
Transport of organic substances in a plant,
