Mass Transport Flashcards
What is the primary structure of a protein?
The sequence of amino acids.
What is the secondary structure of a protein?
The positioning of hydrogen bonds which fold the protein into a helix shape.
What is the teritary structure of a protein?
The positioning of disulfide bridges, hydrogen and ionic bonds which further coils the protein into a specific structure.
What is the tertiary structure?
The way 4 polypeptide chains are joined together.
What are the polypeptides associated with in haemoglobin?
A haem group, Fe2+ ion which can bind to oxygen.
What is the process in which haemoglobin binds to oxygen called?
Loading/ associating
What is the process in which haemoglobin releases its oxygen called?
Unloading/ disassociating
What does the oxygen dissociation curve represent?
The relationship between the saturation of haemoglobin with oxygen and the partial pressure of oxygen.
Explain the shape of the oxygen dissociation curve.
Little oxygen will bind initially as the shape of the haemoglobin molecule makes it difficult for the oxygen to bind. Once one oxygen has been bound the tertiary structure of the protein changes making it easier for another oxygen to bind, making it even easier for another oxygen to bind. However, it then is harder for the fourth to bind as there is a 1/4 chance of the oxygen being close to a binding site as the other are full.
What is positive cooperativity?
Binding of the first molecule makes binding of the second molecule easier.
Does the affinity for oxygen increase or decrease as if the curve moves left?
Increase
Does the affinity for oxygen increase or decrease if the curve moves right?
Decrease.
What is the Bohr effect?
the greater the concentration of CO2 the more readily oxygen will be unleaded from haemoglobin.
How does CO2 cause haemoglobin to release oxygen?
CO2 forms an acidic solution which changes the tertiary structure of the haemoglobin causing it to release the oxygen it is carrying.
Name four features of a transport system
- A suitable medium to carry materials,
- A form of mass transport,
- A closed system of tubular vessels to contain the transport medium,
- A mechanism for moving the transport medium.
What carries blood from the right ventricle to the lungs? What carries blood from the lungs to the right atria?
The Pulmonary artery
The Pulmonary Vein
What delivers blood around the body from the left ventricle. What delivers blood from the body to the right atria?
Aorta
Vena Cava
What carries blood to and away from the kidneys.
Renal artery and renal vein.
What carries blood to and from the liver?
Hepatic artery and hepatic vein
What carries blood to and from the stomach and interstives.
Mesenteric artery and hepatic-portal vein.
What is the name for the atrioventricular valve on the left side of the heart?
Bicuspid
What is the name for the atrioventricular valve on the right side of the heart?
Tricuspid valve.
What is the name for the arteries that supply the heart?
Coronary arteries.
What is relaxation of the heart called?
Total Diastole
What is the contraction of the atria and ventricles called?
Atrial/Ventricular Systole.
What is the purpose of the semi-lunar valves?
Prevent back flow of blood into the ventricles.
What is the calculation for cardiac output?
heart rate x stroke volume
Why are their valves in the veins?
To prevent back flow of blood since the pressure is so low.
What is tissue fluid?
A watery liquid that contains amino acids, ions in solution, fatty acids and oxygen.
How is tissue fluid formed
Hydrostatic pressure forces the tissue fluid out of the blood plasma in the capillaries at the atrial end.
How is tissue fluid returned to the blood at the venous end?
Lower hydrostatic pressure inside the capillaries so tissue fluid is forced back in. Lower water potential so water moves in by diffusion down its concentration gradient.
How does water move across a leaf from the xylem vessels?
Heat supplied by the sun causes evaporation of water from the mesophyll cells.
These cells now have a lower water potential so draw in water from neighboring cells.
Creating a water potential gradient that pulls water up the xylem.
What is cohesion-tension theory?
Water forms hydrogen bonds and so tend to stick together (cohesion) forming a continuous unbroken line across the mesophyll cells and down the xylem.
What is transpiration pull?
The column of water which is pulled up the xylem due to transpiration.
What are xylem vessels formed from?
Dead cells with no end walls to form a series of continuous unbroken tubes,
What is translocation?
Organic molecules and some mineral ions are transported from one part of the plant to another.
Describe a phloem vessel.
Cells arranged into tubes in which their end walls are perforated to form sieve plants, attached to a companion cell.
How does sucrose enter the phloem vessels?
Sucrose is manufactured in photosynthesis, if moves into the companion cell by diffusion down its concentration gradient. Hydrogen ions are actively transported into the cell wall spaces and then the sucrose moves into the phloem vessel by channel proteins with the hydrogen ions by co-transport.
How is sucrose transported within the phloem vessels?
The sucrose entering the phloem vessel lowers the water potential causing water to be drawn in by osmosis from the xylem vessel. Creating hydrostatic pressure so the sucrose is forced downwards towards the sink cells.
How is sucrose transported out of the sieve tubes and into the sink cells?
Moves by active transport into the companion cells and into the sink cells down its concentration gradient. Lowering the water potential in the cells so water moves in also by osmosis. Reducing the hydrostatic pressure in the sieve tubes.
