TYPES OF MEMBRANE PROTEINS
What are integral membrane proteins?
Integral membrane proteins are proteins that are permanently embedded within the cell membrane and have functions like transporting molecules.
What does the Fluid Mosaic Model propose about cell membranes?
It proposes that cell membranes are composed of a phospholipid bilayer with embedded proteins that can move fluidly.
Name one type of membrane extension.
Cilia or flagella.
How do cilia assist in cell movement?
Cilia beat in coordinated waves to move substances across the cell surface.
What role do cholesterol molecules play in the membrane?
Cholesterol helps maintain membrane fluidity and stability by fitting between phospholipid molecules.
What are transmembrane proteins?
Transmembrane proteins are a type of integral membrane protein that span the entire cell membrane.
What is the function of transport proteins?
Transport proteins facilitate the movement of substances across the cell membrane.
What is the difference between cilia and flagella?
Cilia are short and numerous, while flagella are longer and typically fewer in number.
What is the role of flagella in movement?
Flagella rotate or whip back and forth to propel the cell through fluid.
Describe a peripheral membrane protein.
A peripheral membrane protein is temporarily associated with the membrane and often involved in signaling or structural functions.
How do glycoproteins function in cell recognition?
Glycoproteins have carbohydrate chains that act as labels to identify the cell type, aiding in cell recognition.
Why is the membrane considered fluid?
The lipids and proteins in the membrane can move laterally, much like buoys in water, creating a dynamic structure.
How do extensions help single-celled organisms?
Extensions like flagella enable single-celled organisms to move through their environment.
How do membrane proteins assist in crossing the membrane?
Some membrane proteins act as channels or carriers to facilitate the transport of specific molecules across the membrane.
What are the two types of integral membrane proteins?
The two types are transmembrane proteins and integral monotopic proteins.
What is the significance of peripheral proteins?
Peripheral proteins are temporarily associated with the membrane and often play roles in cell signaling.
How do membrane proteins contribute to the mosaic pattern?
The diverse types of proteins embedded in the membrane create a patchwork or mosaic appearance.
Describe the structure of a flagellum.
A flagellum is a whip-like structure made of microtubules that extends from the cell body, aiding in locomotion.
What is the function of phospholipase?
Phospholipase is an enzyme that breaks down phospholipids, aiding in membrane repair and remodeling.
How does the shape of the cell membrane affect its function?
The flexible shape allows for cell movement and interaction with the environment, supporting various functions.
Explain the role of cell adhesion proteins.
Cell adhesion proteins help cells stick to each other or to surfaces, facilitating tissue formation and structure.
What evidence supports the Fluid Mosaic Model?
Studies showing the movement of labeled proteins and lipids in membranes provide evidence for the fluid nature of the membrane.
How do extensions like cilia contribute to multicellular organisms?
Cilia help sweep foreign particles and mucus out of airways, supporting respiratory function.
Discuss how the semipermeable nature of the membrane affects cell function.
The semipermeable membrane allows selective transport of substances, maintaining homeostasis and regulating cell environment.
How do integral monotopic proteins differ from transmembrane proteins?
Integral monotopic proteins are attached to only one side of the membrane, whereas transmembrane proteins span the entire membrane.