B1 Cell Structure And Transport Flashcards
What is diffusion
The spreading of particles of a gas, or any substance in solution (a solute).
What is active transport
Allows cells to move substances from an area of low concemtration to an area of high concentration. This movement is against a concentration gradient.
What does active mean
Energy requiring
What is a concentration gradient
A concentration gradient happens when the concentration of particles is higher in one area than another
What three factors can affect the rate of diffusion
Temperature - speeds it up
Increased concentration gradient - makes it faster (more particles to spread)
Distance - the lower the distance the faster it will happen
Solute
A substance in solution
Gas exchange
The diffusion of oxygen and carbon dioxide in opposite directions in the lungs
Osmosis
A special type of diffusion, only involves the movement of water
What is an isotonic solution
The concentration gradient outside the cell is the same inside the cell
Hypertonic solution
The concentration outside the cell is higher than the internal concentration
Hypotonic solution
The concentration is lower outside the cell than the internal concentration
Turgid
The plant cell is hard and firm
Flaccid
When a plant cell is lacking turgidity so it’s not reciving enough water
Plasmolysis
Is the shrinking of cytoplasym away from the wall of a living cell due to water loss
What does the nucleus do ?
Contains genetic material, including DNA, which controls the cell’s activities
Cytoplasm function
A jelly-like material that contains dissolved nutrients and salts and structures called organelles. It is where many of the chemical reactions happen.
Cell membrane function
controls the movement of substances in and out of the cell.
Its structure is permeable to some substances but not to others.
Mitochondria function
Organelles that contain the enzymes for respiration, and where most energy is released in respiration.
Ribosomes function
Tiny structures where protein synthesis occurs.
Chloroplast function
Organelles that contains the green pigment, chlorophyll,
which absorbs light energy for photosynthesis.
Contains the enzymes needed for photosynthesis.
Cell wall function
Made from cellulose fibres and strengthens the cell and supports the plant.
Permenent vacuole function
Filled the cell sap to help keep the cell turgid
Prokaryotic cells
Cells of bacteria, a simple cell without a nucleus, the DNA is free in the cytoplasym
Eukaryotic cells
Cells of animals,plants and fungi
A type of cell that has a nucleus
Describe osmosis
Osmosis is the movement of water molecules through a partially permeable membrane (e.g. cell membrane) from a dilute solution to a concentrated solution
Describe a sperm cell’s structure
- A long tail whips side to side for movment
- The middle section is full of mitochondria for the energy used by the tail
- Acrosome (pointy head) stores digestive enzymes for breaking down the outer layers of the egg
- A large nucleus contains genetic information
Describe a nerve cells structure
Dendrites - make connections to other nerve cells
Axon - carries nerve impulse from one place to another
Synapses/nerve endings - pass the impulses to another cell or between a nerve cell and a muscle using special transmitter chemicals
Describe a root hair cells structure
- They increase the surface area avaliable for water to move into the cell
- They have a large permenant vacuole that speeds up the movement of water by osmosis
- They have lots of mitochondria needed for active transport of mineral ions into the root hair cell
How does the xylem cell function
Transports water and mineral salts from the roots up to other parts of the plant
Transpiration stream (evaporation and movement of water away from the plant)
What is the function of phloem
Transports surcrose and amino acids from the leaves and other parts of the plant
Process of translocation (the transport of dissolved sugars around a plant in the phloem)
