What is the function of the cell membrane?

Barrier separating cell components from exterior.

What are phospholipids in the cell membrane?

Primary components with polar heads and nonpolar tails.

Various functions like transport and cell recognition.

Controls membrane fluidity by stabilizing phospholipids.

Passive does not require energy, active requires cellular energy.

The cell membrane, composed mainly of phospholipids and proteins, serves as a selective barrier regulating the passage of substances in and out of the cell, crucial for maintaining internal stability.
Understanding the fluid mosaic model of the cell membrane reveals that its dynamic structure allows proteins to move within the lipid bilayer, influencing various cellular functions like transport and recognition, highlighting the complexity and adaptability of this essential cellular component.

What is the function of the cell membrane?
Barrier separating cell components from exterior.
What are phospholipids in the cell membrane?
Primary components with polar heads and nonpolar tails.
What is the role of proteins in the cell membrane?
Various functions like transport and cell recognition.
What is the function of cholesterol in the cell membrane?
Controls membrane fluidity by stabilizing phospholipids.
What is the difference between passive and active transport across the cell membrane?
Passive does not require energy, active requires cellular energy.

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The cell membrane acts as a barrier separating internal cell components from the exterior, controlling movement in and out.
Phospholipids are the primary components of the cell membrane, with polar heads attracted to water and nonpolar tails repelling water.
Phospholipids are amphipathic molecules due to their polar and nonpolar regions, forming a double membrane structure in the presence of water.
Proteins in the cell membrane, like integral and peripheral proteins, play various roles such as transport and cell recognition.
Cholesterol, found only in animal cell membranes, helps control membrane fluidity by stabilizing phospholipids.
The Singer Nicholson model, known as the fluid mosaic model, replaced the Davson Danielli model, showing proteins are not in solid layers but move within the membrane.
Different types of particle movement across the cell membrane are categorized as passive (without energy) or active (requiring cellular energy).
Simple diffusion allows small nonpolar molecules to move freely across the membrane from high to low concentrations.
Facilitated diffusion involves integral protein channels assisting larger polar molecules and ions in moving across the membrane.
Active transport, like the sodium-potassium pump, moves particles against their concentration gradient using ATP energy.