Cell Biology: Cell Membrane Flashcards

Questions and Answers

What is the purpose of the cell membrane?

To contain the cytoplasm and regulate the transfer of materials in and out of the cell.

What kind of things are allowed inside the cell membrane?

Only ions and organic compounds such as Na and H2O.

How is the cell membrane constructed?

It is composed of two layers of phospholipids.

What is a phospholipid composed of?

A phosphate group head and two fatty acid tails. Signup and view all the answers

Define the terms hydrophilic and hydrophobic.

Hydrophilic refers to attracting water, while hydrophobic refers to repelling water. Signup and view all the answers

Cell membranes are present in both living and dead cells.

False Signup and view all the answers

How can we classify proteins associated with the cell membrane?

Based on their location or function. Signup and view all the answers

Detail the two ways a protein can be classified according to its location.

As a peripheral protein or as a transmembrane protein. Signup and view all the answers

What are the types of proteins according to their function?

A protein may be a channel, a gatekeeper, or a glycoprotein. Signup and view all the answers

Explain channel and glycoproteins.

Channel proteins are pores through which materials can pass, while glycoproteins provide unique identity to the cell. Signup and view all the answers

What is an example of glycoproteins in use?

A glycoprotein determines one's blood type and helps recognize foreign invaders. Signup and view all the answers

What is a gatekeeper protein?

Gatekeeper proteins are selectively permeable and open or close based on the materials they encounter. Signup and view all the answers

Study Notes

Cell Membrane Overview

Functions to contain cytoplasm and regulate material transfer in and out of the cell.
Considered a sophisticated organelle integral to cellular function.

Selective Permeability

Allows selective entry of specific ions and organic compounds, such as sodium (Na) and water (H2O).
Ensures that only necessary substances can enter the cytoplasm.

Structure of the Cell Membrane

Composed of a bilayer of phospholipids.
The bilayer arrangement is crucial for its functional properties.

Phospholipid Composition

Made of a hydrophilic phosphate group head and two hydrophobic fatty acid tails.
This structure contributes to the membrane's selective permeability.

Hydrophilic vs. Hydrophobic

Hydrophilic substances attract water, whereas hydrophobic substances repel water.
These properties influence how substances interact with the cell membrane.

Cell Membrane Presence

Present only in living cells, refuting the idea that they exist in dead cells.

Classification of Proteins

Proteins can be categorized based on their location (peripheral vs. transmembrane) or their functions (channels, gatekeepers, glycoproteins).

Types of Membrane Proteins

Peripheral proteins are located on the membrane's exterior, aiding in cell identification.
Transmembrane proteins span the membrane and function as gatekeepers, forming channels for material transport.

Function of Various Proteins

Channel proteins facilitate the passage of materials through the membrane.
Glycoproteins provide cells with a unique identity and assist in immune response.

Glycoproteins in Action

Determine blood type and play a role in identifying foreign invaders in the body.

Gatekeeper Proteins

Maintain selective permeability, opening and closing in response to encountered materials.
Examples include the process of insulin entering cells and neuronal signaling processes.

Description

Explore the essential functions and characteristics of the cell membrane with these informative flashcards. Learn about its role in regulating materials in and out of the cell and understand its selective permeability. Perfect for students studying cell biology and related fields.