Fichas
Diffusion, osmosis and active transport
Fichas del conjunto (17)
- 1What is Diffusion?Diffusion is the process by which particles of a substance spread out from each other, moving from a region where they are in high concentration to a region of low concentration.
- 2What is a concentration gradient?It is the space in which particles of a substance will move down until they are evenly spread
- 3When can diffusion only happen?Particles in the substance must be dissolved and there must be a concentration gradient present between the solutions on either side of the cell membrane.
- 4Give two examples of Diffusion and what happens?Gas exchange in the lungs move oxygen from alveolus region to blood circulating in lungs- gas exchange in leaf moves carbon dioxide into air spaces in leaf
- 5What is active transport?Active transport is a transport process which is used to move dissolved molecules from low concentration to high concentration, against a concentration gradient
- 6What does active transport require?Requires energy from respiration in order to take place.
- 7How is active transport carried out?Active transport is carried out by a series of protein carriers within the cell membrane- these allow dissolved substances to move across membrane by changing shape
- 8Give two examples of active transport?Root hair cells in plant roots use active transport to absorb mineral ions (such as nitrates) from the soil- Small intestine villi cells use active transport alongside diffusion to maximize the absorption of glucose and other substances, eg minerals
- 9What is osmosis?Osmosis is the movement of water from a more dilute solution to a less dilute solution from a permeable membrane
- 10What is a partially permeable membrane?A partially permeable membrane allows small, soluble molecules like water to pass through it freely - but prevents larger molecules from doing so
- 11What happens when water doesn't move to the other side?There is no overall (net) movement of water.
- 12What happens if solutions are less dilute outside the animal cell?Water will move out and the cell will shrivel up (hyper tonic).
- 13What would be the effect in plant cells?in plant cells this would cause the membrane and cytoplasm to shrink away from the cell wall, causing the plant cell to become flaccid
- 14What is the opposite effect in animal and plant cell?The animal cell may burst due to water in and plant cells become turgid as cell wall prevents further expansion due to water(hypotonic)
- 15What is the problem with more complex organisms in diffusion?Diffusion distance is longer and there is a larger volume inside body
- 16What do cells need to function effeiciently and effectively?Enough mineral ions, water and glucose from respiration
- 17Why are sport drinks more efficient to the athlete than soft drinks?It has levels of water, sugar and mineral content that is enough to re hydrate the athlete and make them work longer
Información
- Descripción
- For AQA science and additional science
- Creado por
- Zayed Zaker
- Visitas
- 28
- Valoración