Mass Transport in Animals Flashcards
What is the definition of digestion?
Large biological molecules are hydrolysed by enzymes into smaller molecules that can be absorbed across cell membrane
How are carbohydrates digested?
- Starch is Hydrolysed by Amylase to Maltose
- Maltase is then hydrolysed by Maltase into 2 Glucose molecules
- These are then absorbed by co-transport with Na+
How are lipids digested?
- Lipid droplet is emulsified into small lipid droplets
- These small lipid droplets are hydrolysed by lipase into micelles
- These are then absorbed into the ileum
What is a micelle?
- Tiny droplets of monoglyceride + fatty acids that release monoglycerides close to the surface of cells -> diffuse in to epithelium of small intestine
What does endopeptidase do ?
Hydrolyses peptide bonds WITHIN a polypeptide
What does exopeptidase do?
Hydrolyses the peptide bonds at the ends of the polypeptides
What is membrane bound dipeptidase?
Enzymes attached to membranes (eg ileum) hydrolyse the peptide bonds between dipeptides
What is haemaglobin?
- A protein with a quaternary structure
- Found in red blood cells
- Transports oxygen
What is the Bohr effecct?
- When an organism respires a lot there is a higher concentration of Co2 in the blood
- The higher the CO2 level the more carbonic acid present
- The more acidic the blood the less is Hb’s affinity for O2
- Oxygen ,therefore, more easily unloads at respiring cells
Describe the structure on an artery.
- Narrower lumen than vein
- Folded endothelium
- Thick layer of muscle
- Elastic tissue
What is a benefit of Elastic tissue being able to stretch and recoil?
- It stretches when under high pressure to prevent any damage
- When the ventricles relax it recoils to maintain a smooth pressure
Describe the structure of a vein.
- Thin muscle
- Wide lumen
- One way valves
- Low pressure
Describe the structure of capillaries.
- 1 cell thick
- Lowest pressure
What does the pulmonary artery do?
Transports deoxygenated blood to the lungs
What does the atria do?
Pump blood to the ventricles
What does the Vena Cava do?
Returns blood to the heart from the body
What does the Pulmonary vein do?
Returns oxygenated blood from lungs to the heart
What does the aorta do?
Transports oxygenated blood to the body
What are the atrioventricular valves?
- Uni directional valves
- Open when pressure is higher in the atria than in the ventricles
What are the semi-lunar valves?
Open when pressure is higher in ventricles than in blood vessels
What is atheroma?
The build up of fatty plaque in arteries
What is Thrombosis?
Blood clot in arteries
What is an aneurysm?
When stretching endothelium baloons out through muscle of an artery
What is a myocardial infarction?
A heart attack
How might coronary arteries being blocked by fat deposits affect a person?
- Could cause a heart attack
- Greatly reduces the flow of O2 and glucose to the heart muscle
- Cant respire
Describe how tissue fluid is formed and then returned.
- Hydrostatic pressure is higher in blood than in tissue fluid
- Water and small molecules are forced out
- Large molecules stay inside the capillary ( proteins)
- Pressure decreases as you move along the capillary
- Water potential becomes lower than water potential in tissues as the proteins remain in the blood
- Water moves into the capillary by osmosis, any excess drains into the lymphatic system
