B3.1 Movement in and out Of Cells Flashcards
- Specific to AQA Specification
What is diffusion?
- Diffusion is the random movement of molecules/solutes from an area of high concentration to an area of low concentration until equilibrium is reached
What is osmosis?
- Osmosis is the movement of water molecules from an area of low solute concentration to an area of high solute concentration across a semi-permeable membrane
What causes the movement of water?
- The differences in concentrations of water molecules cause the movement in and out of cells
What is active transport?
- The movement of solutes against a concentration gradient using energy produced by respiration and a carrier molecule
What is needed in active transport?
- A carrier molecule
- Energy released through respiration
What do most sports drinks contain?
- Sugar
- Water
- Ions
How do sports drinks help people doing sport?
- Sugar to replace sugar lost in respiration to release energy
- Water and ions replace lost water and ions via sweat
What happens if water and ions are not replaced during exercise?
- Lack of water and ions cause the balance of the body to be disturbed so cells don’t work as effectively
How are the effectiveness of exchange surfaces increased?
- Large surface area
- Thin, short distance for diffusion
- Ventilation so concentration gradient maintained
- Efficient blood supply so concentration gradient maintained
How is the small intestine effiecient at absorbing food molecules?
- Villi provides large surface area
- Villus very thin, short distance for diffusion
- Constant blood supply(many capillaries), maintain concentration gradient
How are soluble food molecules abosrbed by the small intestine?
- Diffusion
- Active Transport
How are oxygen and carbon dioxide exchanged in the lungs(alveoli)?
- Thin walls, short distance for diffusion
- Constant blood supply/ventilation
- Large surface area
How does the blood supply support the absorbtion of soluble food molecules in the small intestine?
- Extensive network of capillaries absorb products of digestion
Where is the trachea, bronchi, bronchiloes, alveoli and diaphragm in the respratory system?
The Breathing System Trachea Bronchi Bronchioles Alveoli
What happens during inhalation?
- Ribcage moves outwards and upwards
- Diaphragm flattens
- Volume of chest increases
- Pressure in chest increases
- Air drawn in
What happens to the ribcage during inhalation?
- External intercostals muscles contract
- Internal intercostals muscles relax
- Ribs move upwards and outwards
What happens during exhalation?
- Ribcage moves downwards and in
- Diaphragm moves upwards
- Volume of chest decreases
- Pressure in chest decreases
- Air forced out of lungs
What happens to the ribcage during exhalation?
- External intercostals muscles relax
- Internal intercostals muscles contract
- Ribcage moves downwards and in
Why is ventilation needed?
- Oxygen needed for respiration to release energy
- Carbon dioxide(waste product) needed ot of body
- Maintain homeostasis
What is the upper part of the body called?
Thorax
What is the lower part of the body called?
Abdomen
What is a negative pressure ventilator?
- Ventilator cause air to be sucked into the lungs
What is a postive pressure ventilator?
- Ventilator forces air physically into the lungs
Where does exchange of substances occur in plants?
- Carbon dioxide and oxygen exvahnged by diffusion by stomata in leaves
- Water absorbed by osmosis in roots
- Ions absorbed by active transport in roots
How are roots adapted to absorb substances?
- Root hair cells increase surface area
How are leaves adapted to exchange gases?
- Surface area increased by flattened shape and internal air spaces
Which cells control the stomata?
- Guard cells
What is transpiration?
- The loss of water from a plant
What is a transpiration stream?
- The movement of water from the roots to the stem, up the xylem to the leaves where it evaporates through the stomata
How is transpiration increased?
- Evaporation more rapid in hot, dry, windy conditions
Where does osmosis occur in humans?
- Digestive system in large intestine
