Topic 2 - membranes, proteins, DNA and gene expression Flashcards
what is the fluid mosaic model?
what does a phospholipid consist of?
hydrophilic head and 2 hydrophobic tails
what is in a hydrophobic tail?
fatty acids
- water hating
- nonpolar/neutral
- insoluble
what is in a hydrophilic head?
polar group
phosphate
glycerol
- water lover
what is a micelle?
a sphere of molecules with the hydrophobic tails in the center and the hydrophilic heads on the outside
what is a glycoprotein?
phospholipid protein + carbohydrate
*
what is a glycolipid?
lipids + carbohydrate
*
why is cholesterol important to the cell membrane/function?
a lipid produced in the liver
slots between phospholipid tails pushing them together.
- regulates fluidity and stability of membrane
role of channel proteins?
diffusion
span through the membrane
- lined with hydrophilic amino acids and water allowing substances to pass through that are dissolved in water
– intrinsic protein
role of carrier proteins?
use active transport
- change their shape or position to allow molecules or ions to pass through
– intrinsic protein
how does temperature affect the membrane?
what are intrinsic/integral proteins? where are they located?
have hydrophobic amino acids on the outside surface of the protein as they can interact with the hydrophobic fatty acid tails
what are extrinsic/peripheral proteins? where are they located?
integrated near the surface of the membrane or on it internally/externally - do not span the membrane.
role: Structural
- act as enzymes
- receptors for hormones
