B4-Transport Flashcards
What are the factors that affect diffusion
Temperature
When gradient is steepest
Surface area
Define isotonic
If the concentration of solutes in the solution outside the cell is the same as the internal concentration
Define hypotonic
If the concentration of solutes in the solution outside the cell is lower same as the internal concentration
Define hypertonic
If the concentration of solutes in the solution outside the cell is higher same as the internal concentration
What do arteries do
Usually carries oxygenated blood away from the heart to the organs of the body . As the blood is oxygenated it is a bright red colour. The arteries when close to the skin give off a pulse (wrist). This is very dangerous as if the arteries cut the blood will quirt out
What do capillaries do
The capillaries form a huge network of tiny vessels linking the arteries and veins. Capillaries are very narrow and thin. This allows substances such as oxygen and glucose to diffuse easily out of blood cells
What do veins do
The veins carry blood away from the organs towards your heart. This blood is often low in oxygen and a deep red/purple colour. Veins do not have a pulse. They have valves to prevent blood back flow and very thin walls.
What is a double circulatory system
A double circulatory system is on where the blood passes through the heart twice to do one complete circuit of the body. All mammals have a double circulatory system
What are platelets
Platelets are small fragments of cells. They have no nucleus. They are very important is helping the blood to clot at the site of a wound. Blood clotting is a series of enzyme controlled reactions that result in converting fibrinogen into fibrin. This develops a jelly like clot that stops you from bleeding to death
What are red blood cells
They are biconcave discs ( pushed in on both sides) this gives an increased surface area to volume ratio
They are packed with a red pigment called haemoglobin that binds to oxygen.
They have no nucleus making more space for haemoglobin
What are white blood cells
White blood cells are larger than red blood cells but there are fewer of them
They have a nucleus and form a part of the bodies defence system against microorganisms
What is blood plasma
Blood plasma is a yellow liquid
It transports blood cells and some other substrates around the body
Waste carbon dioxide produced by the cells is carried to the lungs
Urea form in liver is carried to kidneys
The small soluble products of digestion pass into the plasma from the small intestine.
What do phloem tubes do
Take sugars up and down the plant
What do xylem tubes do
Take water from the roots up the plant
Which tube is the closest to the centre of the plant
Xylem
