diffusion

diffusion main points / summary

• movement of molecules - from an area of high concentration to low concentration

• passive process - meaning no energy required

• occurs in gases and liquids - e.g. oxygen moving into leaves and carbon dioxide moving out

• helps plants - move gases and liquids in and out for respiration and photosynthesis

diffusion examples in animals

• oxygen in lungs - oxygen in the air has a high concentration, meaning the oxygen from the air moves into the lungs via diffusion, because the oxygen in the blood has a lower concentration, and this allows the body to get the oxygen it needs for respiration to produce energy

• carbon dioxide in lungs - carbon dioxide in the blood has a high concentration, meaning that the carbon dioxide from the blood moves into the lungs via diffusion, because the carbon dioxide in the lungs has a lower concentration, and this allows the carbon dioxide to be exhaled, keeping the body’s pH balance stable

• nutrient absorption in small intestine - the small intestine has a high nutrient concentration, meaning the nutrients from the small intestine move into the bloodstream via diffusion, because the concentration of nutrients in the blood is lower, and this allows the body to absorb and use essential nutrients for energy

• water in kidney cells - the bloodstream has a high water concentration, meaning the water from the bloodstream moves into the kidney cells via diffusion, because the water concentration in the kidney cells is lower, and this allows the body to regulate hydration levels and remove excess waste from the body

• gases in tissues - the bloodstream has a high oxygen concentration, meaning the oxygen from the bloodstream moves into the body tissues via diffusion, because the oxygen concentration in the body tissues is lower, and this supports cellular respiration

diffusion examples in plants

• gas exchange in leaves - the air outside the leaf has a high concentration of carbon dioxide, meaning the carbon dioxide moves into the leaf through the stomata via diffusion, because the concentration of carbon dioxide inside the leaf is lower, and this supports photosynthesis

• transpiration - the inside of the leaf has a high concentration of water vapour, meaning the water vapour moves out of the leaf through the stomata into the air via diffusion, because the concentration of water vapour in the air is lower, and this helps pull water up from the roots and cools the plant

• nutrient uptake by roots - the soil has a high concentration of nutrients like nitrogen, potassium, and phosphorus, meaning the nutrients move into the root cells via diffusion, because the concentration of these nutrients inside the root cells is lower, and this supports the plant's growth and development

• oxygen movement in roots - the soil has a higher concentration of oxygen, meaning the oxygen moves into the root cells via diffusion, because the concentration of oxygen in the root cells is lower, and this supports respiration in the roots for energy production

• movement of water in plants - the soil has a high concentration of water, meaning the water moves into the root cells via diffusion, because the concentration of water in the root cells is lower, and this helps maintain water balance and supports various plant processes