This tutorial explains how substances enter and leave a cell, focusing on diffusion, osmosis, and active transport. It begins with a simple explanation of diffusion, using oxygen and CO2 as examples, highlighting the movement from high to low concentration. Osmosis is introduced as the diffusion of water, emphasizing its importance in cellular processes. Finally, active transport is discussed, explaining how it requires energy (ATP) to move substances against the concentration gradient.

What is the simplest way for substances to enter a cell?

• Endocytosis

• Active transport

• Diffusion

• Osmosis

In diffusion, molecules move from an area of ______ concentration to an area of ______ concentration.

• equal; unequal

• low; high

• high; low

• low; equal

What is a common misconception about diffusion?

• It moves substances from low to high concentration

• It only moves water molecules

• It only moves substances into a cell

• It requires energy

What molecule is represented by CO2?

• Oxygen

• Carbon dioxide

• Water

• Glucose

Tags

NGSS.MS-PS1-1

What is osmosis specifically the diffusion of?

• Glucose

• Oxygen

• Water

• Carbon dioxide

Why does osmosis have a different name than regular diffusion?

• It moves substances from low to high concentration

• It specifically involves water

• It requires energy

• It involves larger molecules

What type of transport requires energy?

• Active transport

• Passive transport

• Osmosis

• Diffusion

What is the energy molecule used in active transport?

• ATP

• CTP

• ADP

• GTP

In active transport, molecules move from an area of ______ concentration to an area of ______ concentration.

• low; equal

• equal; unequal

• high; low

• low; high

Which of the following is an example of passive transport?

• Endocytosis

• Exocytosis

• Diffusion

• Phagocytosis