Topic 1.3- Introduction to Cells Flashcards
What makes up a phospholipid?
The phosphate head which is hydrophilic and the hydrocarbon tail which is hydrophobic
What is the function of a receptor protien?
Hormone binding sites
What is the function of an immobilizaed enzyme
active site on the outside
Cell adhesion
forms tight junctions between grou;s of cells in tissuez and organs
Cell-to-cell communication
communicators (neurotransmitters)
Function of pumps
For active transport which are ATP to move particles across the membrane
What is the function of cholesterol in the cell membrane?
Cholesterol reduces membrane fluidity and permeability to hydrophilic substances. More cholesterol, less charged molecules can enter through the cell.
What was the Davson-Danielli model
There are proteins on both sides of the membrane. The electron micrograph of the cell membrane showed dark bands on either side of light bands.
What was the Singer-Nicholson model
That proteins have varying positions, such as peripheral and intergral. The membrane is also fluid; phospholipids and proteins are more within the membrane
Why was the Davson-Danielli model proved false?
It was false about the structure of the membrane proteins. Many proteins are partly hydrophobic and would not be on the surface of the membrane. Singer and Nicholson also saw that proteins could move around to where they are needed.
