Diffusion and osmosis Flashcards
What is diffusion?
The movement of molecules from an area of higher concentration to an area of lower concentration.
True or False: Diffusion requires energy input.
False
Fill in the blank: Osmosis is the diffusion of __________ through a selectively permeable membrane.
water
What type of molecules typically move across the cell membrane via diffusion?
Small, nonpolar molecules such as oxygen and carbon dioxide.
Multiple Choice: Which of the following is an example of osmosis? A) Movement of glucose into a cell B) Movement of water into a cell C) Movement of ions across a membrane
B) Movement of water into a cell
What is a concentration gradient?
A difference in the concentration of a substance across a space.
True or False: Osmosis can occur without a concentration gradient.
False
What is the role of aquaporins in osmosis?
Aquaporins are channel proteins that facilitate the transport of water across cell membranes.
Fill in the blank: In a hypertonic solution, the concentration of solutes is __________ outside the cell compared to inside.
higher
What happens to a cell placed in a hypotonic solution?
The cell swells and may burst due to water influx.
Multiple Choice: Which process requires a selectively permeable membrane? A) Diffusion B) Osmosis C) Both A and B
B) Osmosis
What is facilitated diffusion?
The process of passive transport of molecules across a membrane via specific transmembrane proteins.
True or False: Active transport is a method of moving substances against their concentration gradient.
True
What is the primary difference between diffusion and osmosis?
Diffusion involves the movement of solutes, while osmosis specifically refers to the movement of water.
Fill in the blank: In a __________ solution, the concentration of solutes is lower outside the cell than inside.
hypotonic
What is an isotonic solution?
A solution where the concentration of solutes is equal inside and outside the cell, resulting in no net movement of water.
Multiple Choice: Which of the following factors does NOT affect the rate of diffusion? A) Temperature B) Size of molecules C) Color of molecules
C) Color of molecules
What is osmotic pressure?
The pressure required to prevent the flow of water across a semipermeable membrane due to osmosis.
True or False: Cells can control the rate of osmosis.
True
What is the main purpose of osmosis in cells?
To maintain cell turgor and homeostasis.
Fill in the blank: During osmosis, water moves toward the area of __________ solute concentration.
higher
Multiple Choice: Which type of solution would cause a cell to shrink? A) Isotonic B) Hypertonic C) Hypotonic
B) Hypertonic
What happens to red blood cells in a hypertonic solution?
They crenate or shrink.
True or False: Diffusion occurs faster in gases than in liquids.
True
What is the effect of temperature on diffusion?
Higher temperatures increase the rate of diffusion.
