Cellular Transport Flashcards
Define cellular transport and explain its significance in cells.
Cellular transport refers to the movement of substances in and out of cells. It is vital for nutrient uptake, waste removal, maintaining cellular homeostasis, and facilitating various cell processes.
Describe passive transport and provide examples.
Passive transport is the movement of molecules across the cell membrane without requiring energy input. Examples include diffusion, osmosis, and facilitated diffusion.
Explain the process of diffusion and its role in cells.
Diffusion is the spontaneous movement of molecules from an area of high concentration to low concentration. It ensures the even distribution of substances within cells and across cell membranes.
Define osmosis and discuss its importance in maintaining cell integrity.
Osmosis is the diffusion of water across a selectively permeable membrane. It helps balance water concentrations inside and outside the cell, preventing excessive swelling or shrinking.
Describe facilitated diffusion and the role of transport proteins.
Facilitated diffusion involves the use of transport proteins to move specific molecules across the membrane. These proteins increase the rate of diffusion for large or polar molecules.
Differentiate between isotonic, hypertonic, and hypotonic solutions and their effects on cells.
Isotonic solutions have equal solute concentrations, causing no net water movement. Hypertonic solutions have higher solute concentrations, leading to cell shrinkage. Hypotonic solutions have lower solute concentrations, causing cell swelling.
Explain active transport and provide examples.
Active transport is the movement of molecules against their concentration gradient, requiring energy (usually ATP). Examples include the sodium-potassium pump and the proton pump.
Describe bulk transport processes: endocytosis and exocytosis.
Endocytosis is the process by which cells engulf large particles or fluids by forming vesicles. Exocytosis involves the release of substances from vesicles into the extracellular environment. Both processes are energy-dependent.
Explain how the selective permeability of the cell membrane is maintained and why it’s important.
The cell membrane’s selective permeability is maintained by phospholipid bilayers and transport proteins. This selectivity ensures that only specific molecules enter or exit the cell, maintaining cellular homeostasis.
