Cell Biology: Fluid Mosaic Model

What is the primary characteristic of the lipid bilayer in the fluid mosaic model?

Which type of membrane protein directly passes through the hydrophobic interior of the lipid bilayer?

How does cholesterol affect membrane fluidity at low temperatures?

What role do carbohydrates play in the cell membrane?

What prevents the destruction of the membrane when temperatures exceed the optimum level?

Which of the following is NOT a function of membrane proteins?

What type of fatty acids contributes to the fluidity of the membrane?

What is the polar part of a phospholipid that interacts with water called?

The Fluid Mosaic Model

Proposed by S. Jonathan Singer and Garth Nicolson in 1972.
Describes the arrangement and movement of lipids and proteins in the cell membrane.
Lipids are hydrophobic due to their hydrocarbon composition.
Phospholipid molecules have a hydrophilic phosphate head and hydrophobic fatty acid tails.
Phospholipid bilayer: heads face outward toward water, tails face inward away from water.

Fatty Acids

Unsaturated fatty acids contain double bonds, creating kinks.
Saturated fatty acids consist of single bonds and have a linear structure.
Cholesterol helps maintain membrane fluidity by occupying kinks of unsaturated fatty acids, especially during temperature fluctuations.

Membrane Proteins

Integral Membrane Proteins: Span the bilayer, interacting with both hydrophilic and hydrophobic regions.
Peripheral Membrane Proteins: Positioned on the membrane surface and do not penetrate the bilayer.

Functions of Membrane Proteins

Signal transmission between cells.
Enzymatic activity to facilitate biochemical reactions.
Cell-to-cell recognition for immune response and tissue formation.
Attachment to cells and other molecules for structural support.
Transport functions to move substances across the membrane.

Carbohydrates in Membranes

Serve as sources of energy, including sugars, starch, and glycogen.
Found in the cell membrane as components of glycoproteins, where carbohydrates are attached to proteins for cell recognition and signaling.

Test your knowledge on the Fluid Mosaic Model, a crucial concept in cell biology introduced by S. Jonathan Singer and Garth Nicolson in 1972. This model explains the structure and function of the cell membrane. Dive into the details of membrane properties and their biological significance.