Biomembrane Structure

16 Questions

What is the main component of the membrane?

Phospholipids

What type of bonds are found in plasmalogens?

Ether linkage

What are the three components of a membrane?

Phospholipids, proteins, and lipid bilayers

What type of molecule is used to regulate tonicity?

Water

What is the role of membrane lipids in the membrane?

To determine the physical properties of the membrane

What type of fatty acid is attached to phospholipids?

Long chains of hydrocarbons

What is the main role of the membrane?

To provide stability to the cell

What type of membrane proteins pass through the membrane multiple times?

Multipass membrane proteins

What type of proteins interact with the membrane?

Transmembrane proteins

What type of membrane lipid is found in the exoplasmic face of the plasma membrane?

Glycoproteins and glycolipids

What type of molecule is amphipathic?

Phospholipids

How many plasma membranes are found in prokaryotic cells?

One

What is the effect of sphingolipids and cholesterol on membrane fluidity?

Decreases

What are the two components of lipids?

Fatty acid and sphingolipid

What type of fatty acids are found in phospholipids?

Long chains of hydrocarbons

Which of the following is true about membrane fluidity?

It increases with the presence of phosphoglycerides.

Study Notes

All cells have a membrane that is essential for their function.
Prokaryotic cells have a single plasma membrane, while eukaryotic cells have many membrane-covered cell organelles.
The membrane is made of phospholipids that spontaneously form bilayers.
Each lipid layer is called a leaflet.
The bilayer is embedded with many types of proteins.
The membrane is selectively-permeable and provides stability to the cell.
The cell maintains tonicity by regulating the levels of water inside and outside of the cell.
Membrane lipids are amphipathic and are composed of two segments with very different chemical properties.
Phosphoglycerides have various head group attachments to the phosphate group, while sphingolipids have a single fatty acid attached by an ether linkage.
Fatty acids of phospholipids are long chains of hydrocarbons with various degrees of saturation.
Plasmalogens have one fatty acid attached by an ether linkage and one by an ester linkage.
Membranes are conserved across different cells and are composed of phospholipids, proteins, and lipid bilayers.
Membrane lipids play an important role in determining the physical properties of membranes.
Membrane fluidity decreases with the presence of sphingolipids and cholesterol, while it increases with the presence of phosphoglycerides.
Membrane lipid distribution is asymmetrical between exoplasmic and cytoplasmic leaflets, with cholesterol being fairly evenly distributed.
Membrane proteins interact with membranes in three ways: transmembrane proteins pass through the membrane once, multipass membrane proteins pass through the membrane multiple times, and glycoproteins and glycolipids are only found in the exoplasmic face of the plasma membrane.