Biology - Cells, Exchange and Transport

Cells, Exchange and Transport

80 cards   |   Total Attempts: 182
  

Cards In This Set

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Decribe the function of vesicles.
To transport substances in and out of the cell and between organelles. Some are formed by the Golgi apparatus or the endoplasmic recticulum, while others are formed at the cell surface.
What is the function of chloroplasts?
They are the site where photosynthesis takes place. Some parts of photosynthesis happen in the grana, and other parts happen in the stroma (liquid part).
What is the function of the centrioles?
They are involved in the separation of chromosomes during cell division. They move to opposite ends of the cell, where spindle fibres form.
Give four things commonly found in plant cells but not in animals cells.
Chloroplast,
Vacuole,
Cell wall,
Plasmodesmata (holes for exchanging substance with adjacent cells)
Name one organelle found only in animal cells.
Lysosome
Give two stuctures that you might find in a prokaryotic cell but no in an animal cell.
Plasmids,
Cell wall
Give four functions of cell's cytoskeleton
The microtubules and microfilament support the cell's organelles, keeping the in position. They also help to strengthen the cell and maintain its shape. They are responsible for the transport of materials within the cell, such as the movement of chromososmes during cell division. The proteins of the cytoskeletom can cause the cell to move, the movement of cilia and flagelle is caused by the cytoskeletal protein filaments.
What is meant by a microscope's resolution?
How detailed the image is. How well a microscope distinguishes between tow points that are close together.
Why is it sometimes necessary to stain an objects before viewing it through a microscope?
Because sometimes the object being viewd is completly transparent, so just looks white because the light or electron rays just pass stright through it.
What are the functions of membranes within cells?
They divide the cell into different compartments to make different functions more efficient. Membranes of some organelles are also folder to increase their surface area. They can also form vesicles to transport substance. Thay control which substances enter and leave the organelle, they are partially permeable.
What are the functions of membranes at the cell surface?
They are to control which substances leave and enter the cell. They are partially permeable (let in some molecules but not others). They allow recognition by other cells (for immune responce). They also allow cell communication.
Explain why the plasma membrance can be descibed as having a fluid-mosaic structure.
Because the phospholips are constantly moving and and their are proteins scattered through the membrane like mosaic tiles.
Diffusion is a passive transport process, what does this mean?
No energy is need for the movement of molecules.
What happend to a plant cell if it is placed in a solution with a higher water potential than the cell?
There is a net movement of water into the cell. The vacuole swells, and the vacuole and cytoplasm puch against the cell wall making it turgid.
What is active transport?
Active transport uses energy to move molecules and ions across plasma membranes, against a concentration gradients.The process involves carrier proteins.