1.3 Membrane Structure Flashcards Preview

IB Biology Topic 1 > 1.3 Membrane Structure > Flashcards

Flashcards in 1.3 Membrane Structure Deck (7)
Loading flashcards...

Describe a phospholipid bilayer membrane.

In water amphipathic phospholipids form double layers with the hydrophilic heads in contact w water (outside and inside of cell) and hydrophobic tails away from water in centre of membrane. This arrangement makes the membrane v stable


What are three types of fatty acids?

Saturated (full of hydrogen), monounsaturated (missing one hydrogen creating a 'kink' - double bond C), polyunsaturated (missing more than one hydrogen creating multiple double bonds between C)


What does hydrophobic mean? What does hydrophilic mean?

Hydrophobic means afraid of water. Hydrophilic means attracted to water.


What is in a triglyceride fat?

Glycerol + three fatty acids


What are some parts of the fluid mosaic model (what to include when drawing phos. Bilayer)

Integral protein (embedded in membrane), ECF and cytoplasm, Peripheral protein (found on surface), glycoprotein (sugar on integral), protein channel, cholesterol


Describe the different models of the membrane over time

1920, bilayer (did not explain proteins), 1930, proposed layers of protein adjacent to bilayer, 1966, discover proteins occupy variety of space in membrane leaving phospholipid molecules free to move


Describe the problems with the Davson-Danielli model (1966) that led to the Singer-Nicholson model

We discovered that transmembrane proteins existed within membranes. Proteins were found to be varied in size and shape and hydrophobic. Proteins can move within the membrane. They would not form a layer on the surface