Cell Transport Flashcards
What is diffusion?
The spreading out of the particles of any substance in solution, or particles of a gas, resulting in a net movement from an area of higher concentration to an area of lower concentration
Exam board definition of diffusion
State the 3 main factors that affect the rate of diffusion?
- Concentration gradient
- Temperature
- Surface area of the membrane
These factors influence how quickly particles can move across a membrane.
What is osmosis?
The diffusion of water/ solvent from a dilute solution to a concentrated solution through a partially permeable membrane
Exam board definition of osmosis.
What is active transport?
Moves** substances** from a more dilute solution to a more concentrated solution (against a concentration gradient) and requires energy from respiration
Exam board definition of active transport.
How are small intestines adapted to exchanging materials?
Specialised for efficient absorption with a large surface area
This adaptation allows for effective nutrient uptake.
How are lungs in mammals adapted to exchanging materials?
Have a large surface area, thin membranes, efficient blood supply, and are ventilated
These features facilitate gas exchange.
How are gills in fish adapted to exchanging materials?
Specialised structures that provide a large surface area and a thin diffusion path
This allows for efficient oxygen uptake from water.
How are roots and leaves in plants adapted to exchanging materials?
Have a large surface area and thin membranes for efficient gas and water exchange
These adaptations support photosynthesis and nutrient absorption.
What is the significance of having a large surface area in exchange systems?
Increases the effectiveness of material exchange
More molecules can be transported in and out of cells.
Fill in the blank: The effectiveness of an exchange surface is increased by having a _______.
[large surface area]
True or False: Active transport does not require energy.
False
Active transport requires energy from respiration.
What is the role of a thin membrane in diffusion?
Provides a short diffusion path
This facilitates quicker movement of substances.
What is the relationship between concentration gradient and diffusion rate?
A steeper concentration gradient increases the rate of diffusion
Particles move faster from high to low concentration.
