Please enable JavaScript.
Coggle requires JavaScript to display documents.
Exchange and Transport (Enzymes and Digestion (Tongue and salivary glands…
Exchange and Transport
Gas Exchange
-
Insects have spiracles which leads to trachea and tracheoles which leads to the muscle fibres. Uses a diffusion gradient + Abdominal pumping. The ends of the tracheoles have water in them for increasing respiration+water potentials
-
In plants, leaves have stomata which allows for the exchange of O2 and CO2
Main point: Short diffusion distance, diffusion gradient, thin spaces and large surface area.
Limiting Water Loss
Insects have small SA:Vol ratio, waterproof coverings and spiracles that can be closed
Plants have waterproof coverings, small SA:Vol ratio and can close the stomata. Xerophytes live in dry areas, they have thick cuticles, rolling up leaves, hairy leaves, stomata pits+grooves and reduced SA:Vol ratio
Human Gas Exchange
-
Internal intercostal muscle = leads to expiration ribs = downwards + inwards, Diaphragm = relax + dome shaped Thorax = Decrease in volume Atmospheric pressure = higher inside lungs
External intercostal muscle = leads to inspiration, ribs = upwards + outwards, Diaphragm = contract + flatten Thorax = Increase in volume Atmospheric pressure = lower inside lungs
Enzymes and Digestion
-
Pancreas secretes proteins that hydrolyses proteins (proteases), lipids (lipase) and starch (amylase)
-
-
Carbohydrases -> carbohydrates into monosaccharides, Amylase hydrolyses alternate glycosidic bonds
-
-
-
-
-
Lipids are broken down into micelles by bile salts (liver) during the process of emulsification (inc SA)
Proteins are broken down by peptidases; endopeptidase, exopeptidase and dispeptidase
Endopeptidases hydrolyse the peptide bonds in the central region of amino acid, forming a series of peptide molecules
Exopeptidases hydolyse the peptide bonds on the end amino acids of the molecule, they release dipeptidases and amino acids
Dipeptidases hydrolyse the bond between dipeptides to form two amino acids (Dipepidases are mem. bound in the ileum)
-
-
These are then transported to the ER to form triglycerides, then passed to the golgi apparatus, they then associate with cholesterol and lipoproteins to form chylomicrons
Chylomicrons move out of the cell by exocytosis and enter the lymphatic system (lacteals) then into the bloodstream
Haemoglobin
Primary structure = Sequence of amino acids, Secondary structure = alpha helix,
Tertiary structure = folding allows it to carry oxygen Quaternary structure = haem group with Fe2+ ion that binds with the O2 molecules
-
-
-
Role of Haemoglobin is to rapidly associate with oxygen at the place of gas exchange + readily disassociate with oxygen when needed
-
Circulatory System
Any organism larger than single cells need a transport system, mammals have a circulatory system
Mammals have a closed, double circulatory system. They have a quick transport system which increases the body temperature hence the high rate of metabolism
Features include; a suitable medium to contain the materials, rapid transport better than diffusion, closed system of tubular vessels, has a mechanism for moving the materials
-
Pulmonary Vein -> Heart -> Aorta -> Arteries -> Organs -> (Kidneys = Renal Vein) -> Veins -> Vena Cava -> Heart -> Pulmonary Artery
-
-
-
-
-
(In to out) Vein = lumen -> lining layer -> elastic layer -> muscle layer -> tough outer layer = much larger than artery
-
Xylem + Phloem
-
-
-
Mostly involves osmosis, diffusion and transpiration
-
-
-
Phloem uses the mass flow theory - water enters the cell via osmosis which contains a high amount of sucrose in. phloem transports the sucrose via active transport, that then makes the water to enter via osmosis, creating a high hydrostatic pressure, forcing the sucrose to other cells.