A membrane that will only allow some substances through and not others.

Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.

The net movement of water molecules from high to low concentration through a selectively-permeable membrane.

The net movement of particles against a concentration gradient using energy.

Moving into and out of the blood: diffusion, osmosis and active transport

Combined science

The human circulatory system

The human heart and double circulatory system, including calculating cardiac output

Human blood cells and blood vessels

Diffusion and surface area to volume ratio

The importance of exchange surfaces and transport systems in humans

Pupils will learn how the components of the human nervous system enable us to respond to changes outside and inside our bodies.

Pupils learned about biological molecules that are essential to life, including sugars and other carbohydrates, proteins and lipids, and the role of enzymes in catalysing the chemical reactions in which these substances are used and made.

This unit covers the human circulatory system, its link to the gas exchange system, and the adaptations of the heart, blood vessels, and blood components. It explains transport mechanisms like diffusion, osmosis, and active transport, and the need for exchange surfaces in multicellular organisms.

Transport and exchange surfaces in humans

Which small particles move into and out of the blood by diffusion?

How does water move in and out of the blood?

Which particles are moved into and out of the blood by active transport?

True or false? Diffusion occurs down a concentration gradient.

Which of these processes require energy to take place?

Sofia: The number of particles that move from one area to another.

Laura: The overall movement of particles.

What is the process by which cells release energy?

What are the reactants needed for cellular respiration?

What gas do red blood cells transport around the body?

Which part of the cell controls what enters and leaves the cell?

The net movement of particles from low to high concentration.

The net movement of particles from high to low concentration.

Which statement best describes diffusion?

Which type of blood vessels has a cell wall that is only once cell thick?

Exit Quiz

Which small particles move into and out of the blood by diffusion?