cell membrane

[ sel mem-breyn ]

noun

, Biology.

1. the semipermeable membrane enclosing the cytoplasm of a cell.

cell membrane

noun

1. a very thin membrane, composed of lipids and protein, that surrounds the cytoplasm of a cell and controls the passage of substances into and out of the cell Also calledplasmalemmaplasma membrane

cell membrane

1. The thin membrane that forms the outer surface of the protoplasm of a cell and regulates the passage of materials in and out of the cell. It is made up of proteins and lipids and often contains molecular receptors. The membranes of organelles within the cell are made of the same basic material as the cell membrane. In plant cells, the cell membrane is surrounded by a rigid cell wall.
2. Also called plasma membrane
3. Compare cell wallSee more at cell

cell membrane

1. The structure separating an animal cell from its environment or a plant cell from its cell wall . The cell membrane is a complex system that allows nutrients to enter the cell and waste products to leave, usually through osmosis .

Word History and Origins

Origin of cell membrane¹

First recorded in 1865–70

Example Sentences

Learning from water bears could also help humans with "knowledge of preserving/restoring cell membranes" and thereby "help prolong the shelf-life of medications such as antibiotics so they could save human lives."

From Salon

Therefore, special transport proteins exist in the cell membranes, acting as specific "gates" to let phosphate into cells.

From Salon

However, the researchers used a new nanotechnology technique to package it into tiny particles called nanomicelles, which are attracted to cancer cell membranes, and break down easily, boosting absorption.

From Science Daily

Having a diet high in fat and cholesterol can cause changes in cell membranes that alter the release of neurotransmitters, too.

From Science Daily

They showed that the previously accepted idea that azoles kill the pathogen cell by causing perforation of the outer cell membrane does not apply.

From Science Daily

More About Cell Membrane

What is a cell membrane?

The cell membrane is the thin layer that encloses a cell’s cytoplasm, which is the substance between the membrane and the nucleus. It allows beneficial things to pass through while blocking harmful ones.

The cell is the basic structural unit of all living organisms. It is a microscopic structure consisting of a nucleus surrounded by the cytoplasm and enclosed by a membrane—the cell membrane. In general, a membrane is a thin barrier or covering.

The membrane consists of a double layer made up of lipid molecules and large protein molecules. Lipids and proteins are the basic building blocks of living cells. They move fluidly in the cell membrane and function like a system of gates, giving the membrane its ability to allow molecules to pass through. For this reason, the membrane is described as semipermeable (meaning it is capable of allowing things to pass through it).

Plants cells also have a rigid outer wall in addition to a cell membrane.

The cell membrane is also called the plasma membrane or the plasmalemma.

Why is the cell membrane important?

To understand why the cell membrane is important, you first have to understand what it does. In essence, the cell membrane serves as the glue that holds the components of the cell together and protects it from outside threats. The membrane regulates what comes into the cell. Among other things, it keeps potentially harmful substances out and keeps nutrients in.

The makeup of the cell membrane includes three crucial components: phospholipids, cholesterol, and proteins. The phospholipids attract and repel water. The layer created by these opposing forces is known as the phospholipid bilayer. It’s responsible for creating the spaces within the membrane and making it a good barrier. Proteins help with transporting cell components across the barrier. Cholesterol also helps with this regulation.

Did you know ... ?

The understanding of the cell membrane is based on what’s called the fluid mosaic model. The fluid mosaic model is a way of describing the structure of cell membranes that likens them to a “mosaic” of different components, consisting of a fluid double layer of molecules. The model was developed by cell biologist S. J. Singer and biochemist Garth L. Nicolson in 1972. It has evolved somewhat since then, but it is now the most accepted way to understand the structure and function of the cell membrane.

What are real-life examples of cell membrane?

Along with the nucleus and the cytoplasm, the cell membrane is one of the main components of a cell. It’s familiar to many biology students.

<iframe loading="lazy" src="https://www.youtube.com/embed/qBCVVszQQNs" width="560" height="315" frameborder="0" allowfullscreen="allowfullscreen"></iframe>

The cell membrane is the cell’s first line of defense against the #COVID19 virus. Using neutron scattering at @ORNL, scientists are investigating therapeutic options for making cell membranes more resistant to viral entry.#NatLabsInTheFight 👉 https://t.co/6P42Ozj57s pic.twitter.com/X2Ef2izG7G

— Neutron Sciences (@ORNLNeutrons) December 1, 2020

General Biology students create bubble frames & blow bubbles to discover how cell membranes behave & function. Who says cell biology can’t be fun! #FluidMosaicModel #AVTigerPride pic.twitter.com/SwBl8WfrzW

— Mr. Garrett Hargiss (@AVScienceGuy) September 11, 2018

 

 

What other words are related to cell membrane?

• cell
• plasma membrane
• plasmalemma
• semipermeable
• lipids
• molecule
• proteins
• phospholipid
• phospholipid bilayer
• cytoplasm
• hydrophilic
• nucleus

Quiz yourself!

True or False?

The cell membrane blocks anything from entering.