Osmosis Flashcards
What is Osmosis?
Osmosis is the net movement of water from a dilute solution to a more concentrated solution through a partially permeable membrane.
What does the word Isotonic mean?
The concentration of the solute in the solution outside the cell is the same as the internal concentration.
What does Hypotonic mean?
The concentration of the solute in the solution outside the cell is lower than the internal concentration.
What does Hypertonic mean?
The concentration of the solute in the solution outside the cell is higher than the internal concentration.
How does Osmosis take place in Plants?
•water always move to areas of lower concentration
•root hair cells take in water from the soil by osmosis
•cell wall stops the cell from bursting
How does Osmosis take place in animal cells?
•animal cells have no cell wall to stop the swelling, just a flexible membrane
•if animal cells are in pure water, they take in water until they burst (Lysis)
•if animal cells are in a concentrated solution they lose water and become shrunken
What is a Turgid cell?
Where the vacuole fills all the space in the cell and pushes against the cell wall
What is a flaccid cell?
Where the vacuole is much smaller and takes up less space, occurs when water moves out of the cell
What is Plasmolysis?
When alot of water leaves the cell and the cytoplasm starts to peel away from the cell wall
What happens when you put an animal cell in pure water?
It takes in as much water as it can before it bursts, this is called Lysis.
What happens when you put an animal cell in a concentrated solution?
It loses water by osmosis until it becomes shrunken or raed.
Active Transport
The movement of substances against a cocnetration gradient, from an area of low concentration to one of high concentration.
Why do cells multiply?
Growth
Repair
Replacing
Cell Cycle
The process by which cells divide
What are the stages of the cell cycle?
•enlargening of the cell and the replication of organelles and genetic information
•division of the DNA (Chromosomes) to either poles of the cell
•the cell splits itself into two ‘daughter’ cells
Mitosis
Stage 2 of the cell cycle, when the chromosomes are pulled to either poles of the cell, replication follows to prodcue two ‘daughter’ cells.
Differentiation
The process of cells becoming specialised to carry out specific functions.
Stem cell
A cell that can become any type of cell needed. Either embryonic or adult stem cells.
What do Stem cells do, and what cant they do?
Stem cells replace or repair damaged or killed cells.
Stem cells cannot divide themselves by mitosis.
What is a meristem?
A place of growth in the plant root that contains undifferentiated stem cells.
Magnification
The degree to which an image is larger than the image itself.
Resoltion
The degree to which it is possible to distinguish between two objects that are close together.
What is the IAM Triangle
Image size= Actual size x Magnification
What is the scale bar formula?
Measured length/actual length= magnification
