Transport Across Cell Membrane Flashcards
Explain the term diffusion
When the particles move from a region of high concentration to a region of low concentration. Until the concentration becomes equal
What is the cell membrane made up of?
Protein and lipids
Does diffusion require energy or no energy?
It is a passive procces so doesn’t need energy
Does diffusion go along the concentration gradient or against?
Along
Which substances can pass freely past the cell membrane
Small molecules such as oxygen carbon dioxide and water
What can pass through the membrane but slowly?
Glucose and amino acids
What can’t pass through the cell membrane at all?
Large molecules such as cell protien and starch
Describe the term osmosis
When water molecules move from a region of high water concentration to a low concentration.
The difference in water concentration that exists between two regions is called the
Water concentration gradient
What would the red blood cell do if it is mixed with water?
It would burst as water has a higher concentration of water so it would diffuse in by osmosis and since the red blood cell does not have a cell wall the cell would burst
What happens when a red blood cell is immersed into a solution with sugar?
Since the sugar has a lower concentration the water moves out of the HWC to the LWC leaving the RBC to shrink
What happened when a plant cell is immersed into pure water?
Since the plant is a lower concentration the water would move into it but as it has a cell wall it would not burst so it would become turgid
What happens when a plant is immersed into sugar solution?
Since the sugar is at lower concentration it would move out of the plant cell leaving it plasmolysed
What is active transport?
The movement of ions or molecules across the cell membrane from a low concentration to a high concentration
Is active transport against the concentration gradient or along?
It’s against
