Movement in and Out of the Cell - Chapter 3 Flashcards
What is diffusion and concentration gradient?
Net movement of particles from an area of higher concentration to an are of lower concentration, as a result of their random movement
Concentration gradient: An imaginary slope from high concentration to a low concentration.
How does diffusion help gas exchange?
Carbon dioxide diffuses into the stomata, due to its random movement, down the concentration gradient. Oxygen diffuses out of the cell due to this. Since cell membranes are easily permeable for gas’s, these gases can easily diffuse in and out of cells.
What is active transport?
The movement of molecules from a low concentration gradient to a low concentration gradient. Against the concentration gradient, using energy from respiration.
How do nitrate ions, use active transport, and why is it requriedin root hari cells. What are carrier proteins.
Nitrate ion from outside cell arrives to a carrier protein, and enters it. The carrier protein changes shape using energy from respiration. The change of carrier protein pushes the nitrate ion into the cell.
Carrier proteins: protein molecules in cell membrane that change shape and move molecules in and of cells using respiration.
What is Osmosis, water potential gradient, high and low water potential?
A net moemnt of particles from a region of higher water ptential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane.
High water potential-> lots of water molecules
Low water potential-> less no of water molecules
Water potential gradient: A difference in water potential between two different areas.
What happens in animal cells, when excess osmosis occurs?
Osmosis, occurs across cell membranes, as cell membranes are partially permeable so they let water in.
Pure water outside:
Meaning a more concentrated solution inside the cell. Osmosis occurs, water diffuses into a cell through a partially permeable membrane. Cell membrane can’t handle that much water so it bursts
Concentrated solution outside:
Meaning a more pure water solution inside the cell. Osmosis occurs, water diffuses out of the cell, through a partially permeable membrane. The cytoplasm shrinks so cell gets smaller.
What is turgor pressure?
pressure of water pushing outwards on a cell wall.
How does a plant cell become turgid?
Osmosis takes place, water diffuses into the vacuole and cytoplasm of the cell, through a partially permeable membrane. Turgid: Description of a plant cells thats tight and firm. the cell wall prevents it from bursting.
How does a plant cell become flaccid?
Osmosis takes place, water diffuses out of the cyctoplasm and vacoule of the plant cell, through a paritally permeable membrained. If plant cell loes, water it loses turgor pressure, cells become soft and flappy (flaccid). Plants lose firmness and wilt. Plasmolysis occurs.
What is playsmolysed
A description of a cell membrane that tears away from a cell wall, will kill the plant cell
