Lab Exercise 5 Flashcards
Define diffusion.
The tendency for small particles to spread from an area of high to low concentration.
What controls the diffusion of molecules in and out of the cell?
Plasma membrane.
Is the plasma membrane selectively permeable?
Yes. It is very selective regarding which molecules can cross it.
What happens to iodine in the dialysis experiment?
Iodine diffuses inside the bag and turns the inside of the bag blue black colour.
What happens to strach in dialysis experiment?
Stays in the bag, too big to diffuse out because it is a polysaccharide.
What is the dialysis membrane similar to?
Plasma membrane.
Define osmosis.
The diffusion of water across a selectively permeable membrane from an area of low to high solute concentration.
What organelle is found in animal cells only?
Centrioles.
What organelles are found in plant cells only?
Chloroplast, cell wall, central vacuole.
How can u tell if a cell is a plant cell?
The central vacuole takes up most space. The cells have a fixed chape due to its cell wall.
What is the difference in function between Elodea cells and onion epidermal cells?
Elodea cells contain chlorophyll to carry out photosynthesis, whereas onion epidermal cells provide protection and prevent water loss.
Do onion cells carry out photosynthesis?
No they grow underground so they dont have access to sunlight.
How is starch stored in potatoes?
Starch is stored in amyloplasts in potatoes.
What are the microscopic structural differences between plant and animal cells?
Plant cells have rigid shape, whereas animal cells have irregular shape.
The nucleus in plant cells are to the side, whereas the nucleus is in the middle in animal cells.
What happens to a plant cell when it is placed in a hypertonic solution?
Water leaves the cell, the vacuole collapses and the plasma membrane shrinks away from the cell wall. This proccess is called plasmolysis.
