Flashcards
Cell Membranes
Cards in this deck (12)
- 1What are the functions of membranes at the cell surface?Partially permeable
Substances can move across by diffusion, osmosis or active transport
Allow recognition by other cells
Cell communication/cell signalling - 2What are the functions of membranes at within cells?Act as a barrier between the organelle and the cytoplasm
Forms vesicles to transport substances between different areas of the cell
Partially permeable
Membranes within organelles acts as barrier between the membrane contents and the rest of the organelle
Site of chemical reactions - 3What is the fluid mosaic model?This model states that membranes are composed of a phospholipid bilayer with various protein molecules floating within it
- 4What does the 'fluid' part of the fluid mosaic theory suggest?The 'fluid' part represents how parts of the membrane can move around freely, if they are not attached to other parts of the cell
- 5What is the difference between intrinsic and extrinsic proteins?INTRINSIC = completely spans the membrane
EXTRINSIC = found only on the inner or outer surface of the membrane - 6Complete the sentences: The proteins also have _________ and ____-_________ regions. Weak __________ bonds between the _______ regions of the proteins and the phospholipids keep the membrane __________.The proteins also have POLAR and NON-POLAR regions. Weak HYDROGEN bonds between the POLAR regions of the proteins and the phospholipids keep the membrane STABLE.
- 7What are the components of cell membranes in the fluid mosaic model?Cholesterol
Carrier/channel proteins
Receptor proteins
Glycolipids
Glycoproteins - 8What is the role of cholesterol in the fluid mosaic model?A steroid
Can fit between the phospholipid molecules, increasing the rigidity and stability of the membranes as a whole
They bind to the hydrophobic tails of the phospholipids, causing them to pack more closely together
Cholesterol has hydrophobic regions, so it is able to create a further barrier to polar substances - 9What is the role of carrier/channel proteins in the fluid mosaic model?Assists and controls the movement of water-soluble ions and certain molecules across the membrane
- 10What is the role of receptor proteins in the fluid mosaic model?Recognises and binds with specific molecules outside the cell, such as hormones and drugs
When a molecule binds to the protein, a chemical reaction is triggered inside the cell - 11What is the role of glycolipids in the fluid mosaic model?Lipids that have combined with polysaccharides and are thought to play a role in cell-to-cell recognition
- 12What is the role of glycoproteins in the fluid mosaic model?This is a combination of a protein and a polysaccharide
Important in cells recognising each other
Act as sites of cell communication (cell signalling)
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- User has deleted their subject information Flashcards on Cell Membranes, created by Deleted user on 05/03/2018.
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- Deleted user · Mar 2018
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- Mar 5, 2018
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- Created by Yinka F · Jan 28, 2018
- Copied by Yinka F · Mar 5, 2018
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