Movement of substances Flashcards
what is diffusion
the net movement of particles from an area highconcentartion to an area of low concentration gradient.
What is osmosis
The movement of water particles from a high water potential to a low water potential through a partially permeable membrane
What is active transport
The net movement against the concentartion gradient from a low concentration to a high concentration which require ATP (Energy released during respiration)
What is Transpiration
The loss of water through evaporation Via the stomata
what factors effect transpiration
Wind speed- increase
Light intensity-increases
temperature-Increase
Humidity- decrease
What factors effect Diffusion
distance- short distance (faster rate of diffusion)
Larger SA:VOL ratio
High temp- more kinetic energy
Good blood supply- maintain conc gradient
what factors effect active transport
Temperature- more kinetic energy (move faster)
Distance- short (faster)
Larger SA:VOL ratio- faster
How is water absorbed by the root hair cell
Via transpiration
water enters the transpiration stream via the root hair cells
what are the adaptations of the root hair cell
The absorption of water and minerals via transpiration
no chloroplast- root hair cell is underground—–> no photosynthesis needed
finger like projections increase SA for osmosis/diffusion
Lots of mitochondria for active transport of minerals
Large vacuole to absorb as much water possible
what are the excretory products of the lungs, kidneys and skin
lungs- carbon dioxide + water Vapour
kidneys- urine
skin- urea, ammonia, lactic acids
what does urine contain
urea, water and ions (ammonia, nitrate)
How does the Kidney carry out the role of excretion.
Ultrafiltration
selective reabsorption
reabsorbtion
What two substances that can not enter bowman’s Capsule
Protein
Red blood cells
White blood cells
what happens in the Glomerulus
ultrafiltration
Blood enters at a high blood pressure through the renal artery
The pressure forces fluid into the Bowmans capsule- glomerulus filtrate
what molecules can get through the glomerulus
ions, water and small molecules like glucose
where do you go after the glomerulus and what happens
Bowmans capsule
fluid passes through - called the filtrate
the fluid does not contain any blood cells or large molecules like protein as they are too big to pass out of the capillary and into the tuble
where do you go after the bowman’s capsule and what happens
PCT - Proximal convoluted tubule
Selective reabsorption occurs
what molecules are reabsorbed in the PCT and why are they useful
Glucose- useful for respiration
Amino aids- useful in the body for protein synthesis and for hormones binds to form enzymes
Sodium and chloride
small amount of urea
What happens in the descending loop of Henle
Water is reabsorbed via osmosis
what happens in the ascending loop of Henle
salts pumped out-
sodium and chloride ions are actively transported out of the ascending loop of Henele
why are salts pumped out of the ascending loop of Henle
Creates a salty Medulla
LWP in the Medulla water moves out via active transport
increases the rate of osmosis more water reabsorbed
where do you go after the Loop of Henle and what happens
DCT - Distal Convoluted tube
more reabsorption of ions occurs
sodium and chloride
where do you go after the DCT and what happens
The Collecting duct
selective reabsorption of water occurs
urine is collected in the pelvis and sent to the ureter
ADH is released - controlling the amount of water reabsorbed
Where is ADH produced
Pituitary Gland
