Lesson 3-4: Cell Membrane And Transport Flashcards
What is the primary function of the cell membrane?
To regulate the movement of substances in and out of the cell.
True or False: The cell membrane is composed primarily of phospholipids.
True
Fill in the blank: The cell membrane is often described as a __________ model.
fluid mosaic
What are the two main types of transport across the cell membrane?
Passive transport and active transport.
What is passive transport?
The movement of substances across the membrane without the use of energy.
Which type of transport requires energy?
Active transport.
What is osmosis?
The diffusion of water across a selectively permeable membrane.
True or False: Facilitated diffusion requires energy.
False
What role do channel proteins play in the cell membrane?
They facilitate the transport of specific substances across the membrane.
Multiple Choice: Which of the following is an example of active transport? A) Osmosis B) Sodium-potassium pump C) Diffusion
B) Sodium-potassium pump
What is endocytosis?
The process by which cells engulf substances from the outside environment.
What is exocytosis?
The process of vesicles fusing with the cell membrane to release contents outside the cell.
True or False: Small nonpolar molecules can easily pass through the cell membrane.
True
What is the role of cholesterol in the cell membrane?
To maintain membrane fluidity and stability.
Define selective permeability.
The ability of the cell membrane to allow certain substances to pass while blocking others.
What is a concentration gradient?
The difference in concentration of a substance across a space.
How does temperature affect the fluidity of the cell membrane?
Higher temperatures increase fluidity, while lower temperatures decrease it.
What is the function of glycoproteins in the cell membrane?
They play a role in cell recognition and signaling.
Fill in the blank: The movement of molecules from an area of high concentration to an area of low concentration is called __________.
diffusion
What is the significance of the sodium-potassium pump?
It helps maintain the electrochemical gradient across the cell membrane.
