Diffusion, Osmosis, Active Transport Flashcards
Things that increase the rate of diffusion
- More particles
- Bigger surface area to diffuse across
- Shorter distance to diffuse
- Temperature
- Mechanical movement (stirring or wind)
What is diffusion
Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration
Which diffuses faster a liquid or a gas?
And why?
Gas.
Because they can move more easily as the particles are more spread out.
The rate of diffusion is faster when the concentration gradient is _________
Bigger
Diffusion is slower when there is a _______ distance over which diffusion occurs
Larger
A plant cell put in a dilute solution becomes _________
Turgid
What is osmosis
The net diffusion of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
Plasmolysed is when the cytoplasm __________
Shrinks
Osmosis will lead to the swelling of a raisin, but it will not burst because …
It is a plant
What will happen if we add acid to a hole in agar (colour)
It will turn red/pink
What type of transport protein is involved in active transport
Carrier protein
What is active transport
Active transport is the process by which dissolved molecules move across a cell membrane from a lower to a higher concentration
The only way active transport can take place is to use energy produced by
Respiration
Cells involved in active transport usually have a lot of _________________ to provide the energy they need
Mitochondria
A typical example of diffusion
In the lung of a mammal, oxygen moves from the alveoli to the blood
A typical example of osmosis
In the kidney of a mammal, water moves from the nephron to the blood
A typical example of active transport
In a flowering plant, there is an uptake of mineral salt which moves from the soil to the cytoplasm in a root hair cell.
What happenes when a plant is watered well
All its cells will draw water in by osmosis and become plump and swollen (Turgid)
The contents of the cell push against the cell wall - this is called __________pressure. What does this do?
Turgor pressure
Helps support the plant tissues
How does a plant become flaccid
If there’s no water in the soil - cells lose water and lose turgor pressure
What sort of molecules can diffuse through cell membranes
Glucose
Amino acids
Water
Oxygen
GAWO
What sort of molecules can’t diffuse through cell membranes
Starch
Proteins
SP
Name 3 factors which affect the movement of substances
Surface area to volume ratio
Temperature
Concentration gradient
Small things have a __________ sure area to volume ratio
Greater
The rate of diffusion, osmosis and active transport is higher in cells with a _________ surface area to volume ratio
Larger
