This deep dive covers Real-World Applications of Cell Transport within Cell Transport for GCSE Biology. Diffusion, osmosis, active transport, factors affecting transport, surface area to volume ratio, and practical investigations It is section 6 of 19 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

🌍 Real-World Applications of Cell Transport

🫁 Gas Exchange in Lungs

Process: Diffusion of oxygen and carbon dioxide

Oxygen diffuses from alveoli into blood (high to low concentration)
Carbon dioxide diffuses from blood into alveoli
Concentration gradients maintained by breathing and blood flow

Alveoli Adaptations:

Millions of tiny air sacs = huge surface area
Walls one cell thick = short diffusion distance
Rich blood supply = maintains concentration gradients
Moist surface = gases dissolve for diffusion

🌱 Root Hair Cells

Process: Absorption of water and minerals

Water absorbed by osmosis from soil
Mineral ions absorbed by active transport
Active transport needed because soil often has lower mineral concentration

Root Hair Adaptations:

Long projections = increased surface area
Thin cell walls = easy passage of substances
Many mitochondria = provide ATP for active transport
Permeable membrane = allows water and ion movement

🍽️ Small Intestine

Process: Absorption of digested food

Glucose absorbed by diffusion and active transport
Water absorbed by osmosis
Active transport used when glucose concentration is low

Villi Adaptations:

Millions of finger-like projections = massive surface area
Rich blood supply = maintains concentration gradients
Thin walls = short diffusion distance
Microvilli = further increase surface area

🫀 Kidney Function

Process: Filtering blood and reabsorbing useful substances

Glucose reabsorbed by active transport
Water reabsorbed by osmosis
Waste products removed by diffusion

Why Active Transport for Glucose?

Glucose concentration in filtrate is lower than in blood, so glucose must be moved against its concentration gradient back into the blood.

Practice questions for Cell Transport

Which statement best describes diffusion?

A. The movement of particles from a region of low concentration to high concentration
B. The net movement of particles from a region of high concentration to low concentration
C. The movement of water molecules through a partially permeable membrane
D. The movement of particles using energy from respiration

1 markfoundation

Explain how osmosis causes a plant cell to become plasmolysed when placed in a concentrated sugar solution.

3 marksstandard

Quick recall flashcards

Define diffusion

The movement of particles from an area of high concentration to an area of low concentration down a concentration gradient. No energy is required (passive process).

Define osmosis

The movement of water molecules from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration) through a semi-permeable membrane.

Real-World Applications of Cell Transport