Cell membrane Flashcards
(19 cards)
What do glycolipids and glycoproteins contain that allows them to act as receptor molecules?
Carbohydrate chains
These chains exist on the surface of the cell.
How do glycolipids and glycoproteins interact with substances?
They bind with certain substances at the cell’s surface.
What are the three main types of receptors associated with glycolipids and glycoproteins?
- Signalling receptors for hormones and neurotransmitters
- Receptors involved in endocytosis
- Receptors involved in cell adhesion and stabilisation
What role do carbohydrate parts of glycolipids and glycoproteins play in cell adhesion?
They can form hydrogen bonds with water molecules surrounding the cell.
What is one function of glycolipids and glycoproteins in relation to cell-to-cell recognition?
They act as cell markers or antigens.
Give an example of antigens that are glycolipids and glycoproteins.
ABO blood group antigens.
Fill in the blank: Glycolipids and glycoproteins enable cells to act as _______.
[receptor molecules]
What do transport proteins create to allow ions and polar molecules to travel through the membrane?
Hydrophilic channels
Transport proteins facilitate the movement of substances across the cell membrane.
What are the two types of transport proteins?
- Channel (pore) proteins
- Carrier proteins
Each type of protein has a distinct mechanism for transporting substances.
What is the specificity of transport proteins?
Specific to a particular ion or molecule
This specificity ensures that only certain substances can pass through the membrane.
What role do transport proteins play in cellular function?
Allow the cell to control which substances enter or leave
This regulation is crucial for maintaining homeostasis within the cell.
What happens to membranes when there is an increased proportion of saturated fatty acid chains?
Membranes become less fluid due to tightly packed chains and high intermolecular forces.
How does a lower temperature affect membrane fluidity?
Membranes become less fluid as molecules have less energy and are more closely packed.
Fill in the blank: Membranes become less fluid when there is an increased proportion of _______.
saturated fatty acid chains
True or False: An increase in temperature generally increases membrane fluidity.
True
What causes the structure of membranes to be more closely packed at lower temperatures?
Molecules have less energy and are not moving as freely.
What happens to membranes when there is an increased proportion of unsaturated fatty acid chains?
Membranes become more fluid due to the bent chains being less tightly packed together, resulting in fewer intermolecular forces.
Unsaturated fatty acids have one or more double bonds, which introduce kinks in the fatty acid chains.
How does temperature affect membrane fluidity?
At higher temperatures, molecules have more energy and move more freely, which increases membrane fluidity.
This phenomenon is crucial for maintaining the proper function of membranes in living organisms.
