Membrane Transport Overview

Which type of molecules can move through the cell membrane by simple diffusion?

Osmosis is a form of passive transport that involves the movement of water molecules across a membrane.

Name two factors that influence the type of passive transport a molecule undergoes.

Passive transport relies on the kinetic energy of molecules, also known as __________.

Match the types of passive transport with their descriptions:

What is the primary reason molecules move from high concentration to low concentration?

Passive transport requires chemical energy from the cell.

What is Brownian motion?

In passive transport, the movement of molecules occurs from an area of ______ concentration to an area of ______ concentration.

What maintains homeostasis in relation to membrane transport?

Match the transport types with their characteristics:

A concentration gradient only exists when there is an equal number of molecules on both sides of a membrane.

What occurs when molecules achieve dynamic equilibrium across a membrane?

Membrane Transport Overview

Membrane transport moves molecules, ions, and waste across cell membranes to maintain homeostasis.
Energy is the ability to do work. Potential energy is stored energy, while kinetic energy is the energy of motion.
Molecules move in straight lines until acted upon.
Brownian motion is random, unpredictable molecular movement.
Concentration gradient is the difference in the concentration of molecules across a membrane.
Dynamic equilibrium occurs when equal concentrations are reached on both sides of a membrane, and the rate of molecules moving in and out are equal.
Molecules move from high to low concentration to reach equilibrium.

Passive Transport

Passive transport is the random movement of molecules from high to low concentration, requiring no energy input from the cell.
Molecules have kinetic energy from random movement, Brownian Motion, driving this movement.
Cells provide channels/openings for passive transport to occur.
Examples of molecules that use passive transport include oxygen, CO2, nitrogen gas, and benzene, as a result of being small, non-polar molecules, which allow the molecules to be able to dissolve into the phospholipid bilayer of the membrane itself.
Passive transport is considered passive because the cell doesn't actively do work to move the substances.

Types of Passive Transport

Simple Diffusion: Small, non-polar molecules diffuse directly across the phospholipid bilayer.
Osmosis: The diffusion of water across a selectively permeable membrane.
Facilitated Diffusion: Larger or charged molecules use transport proteins (carrier proteins or ion channels) to cross the membrane.
Filtration: Movement of molecules through a membrane due to a pressure difference.

This quiz covers the essential concepts of membrane transport, including passive transport mechanisms, energy types, and concentration gradients. Understand how molecules move across cell membranes and the importance of dynamic equilibrium for maintaining homeostasis. Test your knowledge on these fundamental biological processes.