1.7 Exchange of nutrients and wastes
types of nitrogenous waste (recognise)
Urea
Uric acid
Ammonia
Requires very little energy
Requires more energy than ammonia
Requires a lot of energy
Requires a lot of water
Requires some water
Requires no/little water
Fish and amphibians(frogs)
Mammals
Reptiles and birds
Parts of the nephron (explain)
Bowman's capsule
Tubule (site of reabsorption)
Glomerulus
Loop of Henle
Distal convoluted tubule
proximal convoluted tubule
Network of capillaries which filter various substances from the blood
Surrounds the glomerulus, collects nitrogenous waste and other small soluble molecules forced by the high pressure in the glomerulus
Site of selective reabsorption
mineral ions (active transport)
glucose and amino acids
Establishing a salt gradient (water & salt reabsorption by active transport)
some water
Site of reabsorption
sodium (mineral ion/active transport)
water (osmosis)
Glomerular filtration: As a high pressure of blood from artery flows into the capillaries, it allows small molecules (glucose, amino acids, etc..) to pass from the glomerulus into the Bowman's capsule.
Selective reabsorption
occurs along the kidney tubules
purpose: to recover vital substances and ions.
Collecting Duct
Concentrates urine by reabsorping water (osmosis)
Secretion
??
Role of digestive enzymes (descirbe)
characteristics of absorptive surfaces (identify)
Protease
Lipase
Amylase
Large surface area
Thin and single layer
Increases contact area with enzymes/absorption
Increases diffusion rate
Microvilli(extensions on villi) on villi increases the surface area for absorption
Breaks down lipids into glycerol and fatty acids
Breaks down proteins to amino acids
breaks down amylose into disaccharide