Membrane Structure and Function

These flashcards cover essential aspects of membrane structure and function as discussed in the lecture.

What is the primary component of the lipid bilayer in cell membranes?

Phospholipids.

What does the fluid mosaic model describe?

How proteins are embedded in the phospholipid bilayer.

In which year was the fluid mosaic model proposed?

1972.

What are the two types of membrane proteins?

Integral membrane proteins and peripheral membrane proteins.

What role do proteins play in the plasma membrane?

They provide functions and give characteristics to different membranes.

What are the two key parts of a phospholipid?

Hydrophilic heads and hydrophobic tails.

What is the significance of membrane fluidity?

Membrane function depends on fluidity; it allows diffusion and interaction of proteins.

What can shorten the hydrophobic tails of phospholipids?

Shorter fatty acids increase membrane fluidity.

How does cholesterol affect membrane fluidity?

Cholesterol stiffens membranes but also helps regulate fluidity.

What is the orientation of phospholipids in the membrane?

Asymmetrical.

What kind of molecules do hydrophilic heads of phospholipids attract?

Water molecules.

What are glycoproteins?

Proteins with oligosaccharides attached.

What is the key function of transport proteins?

To facilitate the movement of molecules across the membrane.

What is the role of membrane anchors?

To link intracellular filaments to extracellular matrix proteins.

How can membrane proteins be extracted?

Using detergents that have both hydrophobic and hydrophilic characteristics.

What is the term for the carbohydrate layer formed by glycolipids and glycoproteins?

The glycocalyx.

What is the cytosolic face of the membrane?

The side of the plasma membrane facing the cytoplasm.

What property of phospholipids makes them form bilayers in water?

Amphipathic nature.

What do porin proteins do?

Form water-filled channels in bacterial membranes.

How can the lateral mobility of membrane proteins be restricted?

By tethering to the cytoskeleton or extracellular matrix.

What is a common characteristic of membrane lipids?

All are amphipathic.

What type of structure do the hydrophobic tails of phospholipids contribute to in the membrane?

A bilayer structure.

What year was the Davson-Danielli model proposed?

1935.

What is the purpose of the cell cortex?

To provide structural support to the cell membrane.

What increases membrane permeability?

Higher levels of unsaturation in fatty acids.

What maintains the orientation of membrane proteins during transport between compartments?

Membranes retain their orientation.

What are integral membrane proteins?

Proteins that are directly attached to the membrane and require disruption of the bilayer to extract.