6: Cell Membranes Flashcards
Module 1, Lesson 6
All plasma membranes contain…
Lipids and proteins
____ are a fundamental structure in plasma membranes.
Phospholipids
____ on the outer surface of the membrane create a sugar coat (glycocalyx).
Carbohydrates
What are the functions of the glycocalyx?
(three)
- Protects the cell
- Helps the cell interact with other cells
- Helps other cells recognize the cell
Phospholipids are composed of a ____ head group and two ____ tails.
Hydrophilic head group
Hydrophobic tails
The tails of phospholipids are long chains of…
Fatty acids
Phospholipids that connect fatty acids to a phosphate group using glycerol are called…
Glycerol phospholipids
True or false:
Cells can control the length of a phospholipid’s fatty acid tail.
True
A fatty acid that contains double bonds is considered…
Unsaturated
A fatty acid that does not contain double bonds is considered…
Saturated
In water, phospholipids associate into structures such as the…
(two)
Micelle and bilayer
A spherical structure where the head groups are on the outside is called a…
Micelle
A continuous sheet with two outside edges made up of head groups is called a…
Bilayer
List the three types of monolayers.
Faces, leaflets, surfaces
Phospholipid bilayers give the cell membrane its property of…
Selective permeability
Which types of molecules can freely cross the plasma membrane?
Small and nonpolar (hydrophobic)
Which types of molecules can only cross the plasma membrane slowly?
Polar, hydrophilic
The ____ model of the plasma membrane visualizes it as a 2D fluid where proteins are either inserted or dissolved.
Fluid mosaic
The two main types of proteins in the plasma membrane are…
Integral proteins and peripheral proteins
____ is a lipid inserted into the bilayer that enhances barrier properties.
Cholesterol
Phospholipids and proteins can diffuse ____ in membranes.
Laterally
Phospholipids and proteins are able to diffuse in membranes due to…
Weak hydrophobic interactions
List three things that can reduce the fluidity of the plasma membrane.
- Lower temperatures
- Longer fatty acid tails
- Saturated fatty acid tails
Cells can reduce the affinity of phospholipids for each other by…
Adjusting the length of the tails or the number of bonds in the tails
Proteins embedded in the phospholipid bilayer are called the…
Integral membrane proteins
True or false:
We can isolate integral membrane proteins without destroying the membrane.
False
Because the proteins are embedded in the bilayer, isolating them requires destroying the membrane.
Proteins that pass through the bilayer and are exposed on each side of it are called…
Transmembrane proteins
Transmembrane proteins with only one transmembrane domain are called…
Single-pass proteins
Transmembrane proteins with multiple transmembrane domains are called…
Multi-pass proteins
Proteins that are attached to lipids or fatty acids are called…
Lipid anchor proteins
Transmembrane proteins and lipid anchor proteins are types of…
Integral membrane proteins
True or false:
A single lipid anchor protein is only found on one side of the bilayer or another.
True