transport in cells + Plant tissues, organs and systems Flashcards
What is Active transport?
Substances being moved from an area of low concentration to an area of high concentration against the concentration gradient
What does active transport require?
Energy
Why is active transport required?
To move molecules against a concentration gradient
What process is used for plants to take in ions from soil around it?
Active transport
What plant structure first takes in the ions?
Root hairs
What is active transport used for in animals?
Glucose molecules moved across gut wall into blood
What is active transport used for in plants?
So the plant can take in mineral ions
Where does energy come from for active transport in animals?
Respiration
Where does energy come from for active transport in plants?
Photosynthesis
Is energy required for osmosis?
No
Is energy required for diffusion?
No
What is diffusion?
Substances move into the root hair from a high concentration in the soil to a low concentration in the root hair down a concentration gradient
What is osmosis?
Water moving from a concentrated to dilute solution through a semi permeable membrane down a concentration gradient
What is active transport?
Substances moving across a concentration gradient
What is isotonic point?
No overall movement of water in or out of the cells
How are sugars transported in the plant?
Translocation
What is the term for when water evaporates off a plants leaves and water moves up the xylem
Transpiration
What is the xylem strengthened by?
Lignin
What effects the rate of transpiration?
Light intensity
Temperature
Air flow
Humidity
How does CO2 enter the leaf?
Diffuses into the leaf through stomata (in the lower eperdermis)
Moves into spongy mesophyll (gaps for easy diffusion)
Moves into the palisade mesophyll (contains lots of chloroplasts + majority of photosynthesis occurs)
How does sunlight reach the site of photosynthesis?
Passes through eperdermis to reach palisade cells
How is water loss prevented?
- Waxy cuticle (top layer)
- Guard cells close stomata (Reduce evaporation)
What is the definition of turgid?
cells that are full of water
How is water loss balanced with CO2 absorption? (bottom layer)
Guard cells control opening of stomata
High water concentration - guard cells turgid (open stomata)
Low water concentration - Guard cells loose water through osmosis - Become flaccid - Stomata closes
