Explaining Adaptations in Specialised Cells Flashcards
How are root hair cells adapted for diffusion
Are adapted for the absorption of ………….
Have a specialised ……… (the root ‘hair’) that increases the ………….. so the rate of water uptake by osmosis is greater (can absorb more …………………. than if the surface area was lower)
Have …………… walls than other plant cells so that water can move through easily (due to shorter ……………….distance)
Have a permanent vacuole containing cell sap, which is more………………..than soil water. This ensures a …………….gradient is ………….
water and mineral ions from soil
shape
cell’s surface area water and mineral ions
thinner
diffusion
concentrated
high water potential
maintained
Epithelial cells of the small intestine: is adapted for …………
Have ………….. (highly folded sections of the cell membrane), which increases the cell’s surface area so the rate of diffusion of the products of …………. is greater (more particles can be exchanged in the same amount of time)
Each villus of the small intestine has a constant ………………., which continually transports the products of digestion away from the ……… cells.
This maintains a ……………… across the ……………. cell exchange surface (between the…………… of the small intestine and the ….. of the epithelial cell)
diffusion
microvilli
surface area
digestion
blood supply
epithelial
high concentration gradient
epithelial
lumen
interior
epithelial transports what molecule
glucose from epithelial high conc to blood stream low conc
What are the specialised cells adapted for facilitated diffusion
Neurones, muscle cells and some kidney cells are examples of cells that are adapted for the rapid transport of molecules across their membranes via facilitated diffusion
Certain kidney cells:
Have cell …………………… that contain a very high number of aquaporins
Aquaporins …………………….
The aquaporins allow these kidney cells to …… water, stopping it from being ………………..
membrane
are special channel proteins that allow the facilitated diffusion of water through cell membranes
reabsorb
unnecessarily excreted by the body
Neurones and muscle cells
Are involved in the transmission of electrical impulses around the body
They have cell membranes that contain channel proteins for ……………….. ions
The opening and closing of these channel proteins (and the resulting facilitated diffusion of these different ions),
as well as the……… of these channel proteins, plays an important role in the speed of electrical transmission, both along the membranes of neurones (during nerve impulses) and in muscle cells (during muscle contraction)
sodium, potassium and calcium ions
number
In the case of the kidney cells described above, water is transported across the cell membrane via facilitated diffusion through channel proteins. Don’t forget, however - water can also diffuse through cell membranes (this can occur even though it is a polar molecule because it is a relatively small molecule).