Untitled Deck Flashcards
(18 cards)
What is the role of the cell membrane?
The cell membrane is selectively permeable, controlling what goes in and out of the cell to maintain homeostasis.
Homeostasis refers to the organism’s need to maintain stable internal conditions like temperature, pH, and concentration of materials.
What are the characteristics of passive transport?
Passive transport requires no extra energy from the cell and moves molecules from high concentration to low concentration areas down the concentration gradient.
Examples include diffusion, facilitated diffusion, and osmosis.
Define diffusion.
Diffusion is the spreading of molecules across a membrane until equally concentrated.
Example: Oxygen and Carbon Dioxide.
What is facilitated diffusion?
Facilitated diffusion is when a transport protein helps diffusion of molecules that normally couldn’t pass, such as large or polar molecules.
Example: Glucose/sugar, sodium/salt.
What is osmosis?
Osmosis is the diffusion of water across the cell membrane from high to low concentration.
What are the characteristics of active transport?
Active transport requires extra energy (ATP) to move materials from low concentration to high concentration against the concentration gradient.
This process is essential for concentrating key molecules or removing waste.
What are molecular pumps in active transport?
Molecular pumps are mechanisms where the cell uses energy to pump molecules across the membrane through a protein channel.
Examples include Calcium (Ca2+), potassium (K+), chlorine (Cl-), and sodium (Na+).
What is endocytosis?
Endocytosis is the process where the cell uses energy to import large amounts of materials into the cell using a vesicle.
What is phagocytosis?
Phagocytosis is a type of endocytosis where the cell ‘eats’ by engulfing solids into a vesicle and digesting them.
What is pinocytosis?
Pinocytosis is a type of endocytosis where the cell ‘drinks’ by engulfing liquids into a vesicle and digesting them.
What is exocytosis?
Exocytosis is the process where the cell uses energy to export large amounts of materials out of the cell using a vesicle.
Example: Nerve cells releasing neurotransmitters.
What happens in hypertonic solutions?
In hypertonic solutions, water concentration is below what’s in a cell’s cytoplasm; water moves out, and the cell shrivels.
What happens in hypotonic solutions?
In hypotonic solutions, water concentration is above what’s in a cell’s cytoplasm; water moves in, and the cell swells.
What are isotonic solutions?
Isotonic solutions have identical water concentrations to the cell’s cytoplasm; the cell stays the same.
Fill in the blank: Cellular transport is divided into _______ and _______.
passive transport, active transport
True or False: Passive transport requires energy to move molecules.
False
What is the specific type of passive transport that involves water diffusion?
Osmosis
How does the type of solution (hypertonic, hypotonic, isotonic) affect the cell’s behavior?
The type of solution determines whether the cell shrivels, swells, or remains the same.
