Movement In And Out Of Cells Flashcards
(22 cards)
What percentage of our body weight is made up of water?
About 70% of our body weight is made up of water.
What role does water play in chemical reactions in the body?
Water is an important solvent; substances must dissolve in water for chemical reactions to take place.
How does water help in controlling body temperature?
When water in sweat evaporates, it removes excess heat from our bodies, preventing overheating.
Why is water necessary for photosynthesis in plants?
Water is needed for photosynthesis, which is essential for plant growth and energy production.
What processes allow substances to move in and out of cells?
Diffusion, Osmosis, or Active transport.
What is diffusion?
Diffusion is the net movement of molecules from a region of higher concentration to a region of lower concentration.
What factors influence the rate of diffusion?
Surface area to volume ratio, Distance, Temperature, Concentration Gradient.
What is osmosis?
Osmosis is the net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane.
Define hypotonic solution
A solution with higher water potential (dilute solution).
Define hypertonic solution
A solution with lower water potential (concentrated solution).
Define isotonic solution
A solution with equal concentration of water and solute molecules.
What happens to plant cells when they become turgid?
They are full of water and contain a high turgor pressure, preventing further water entry.
What is the effect of water moving into a plant cell by osmosis?
The vacuole gets bigger, pushing the cell membrane against the cell wall, making the cell rigid and firm.
What happens to a plant cell in a hypertonic solution?
Water moves out of the plant cell, causing it to become flaccid and plasmolysed.
What are the consequences of osmosis in animal cells?
Animal cells can lose or gain water, leading to crenation or bursting, respectively.
What is active transport?
Active transport is the movement of molecules through a cell membrane from a region of lower concentration to a region of higher concentration using energy.
What is an example of active transport in the human body?
Uptake of glucose by epithelial cells in the villi of the small intestine.
Fill in the blank: The energy for diffusion and osmosis comes from the _______.
kinetic energy of random movement of molecules and ions.
True or False: Plant cells can burst when they take in too much water.
False. The cell wall prevents bursting.
What is the role of plasma in blood regarding water?
Plasma in blood transports dissolved substances around the body.
How does temperature affect the rate of diffusion?
Higher temperature increases molecular movement, resulting in a faster rate of diffusion.
