Bio Test Flashcards
What is the main function of the cell membrane
Regulates what enters and leaves the cell
What is the main function of the cell wall
To provide support and protection for the cell
What happens during diffusion
Particles move from an area where they are more concentrated to an area where they are less concentrated
What is osmosis
The diffusion of water through a selectively permeable membrane
The core of nearly all cell membranes is a double layered sheet called a
Lipid bilayer
What is the function of the proteins attached to a cell membrane
Proteins form channels and pumps that help move material across the cell membrane
What is the function of the carbohydrates attached to a cell membrane
Act like chemical identification cards, allowing individual cells to identify one another
In what organisms are cell walls found
Plants, algae, fungi
The cell wall lies inside the cell membrane
False
What are plant cell walls mostly made of
Cellulose, a tough carbohydrate fiber
What is the concentration of a solution
The mass of solute in a given volume of solution, or mass/volume
What is meant when a system has reached equilibrium
The concentration of the solute is the same throughout a system
What does it mean that biological membranes are selectively permeable
That some substances can pass across them and others can’t
Two solutions are isotonic
The solutions are the same strength
A solution is hypertonic
The solution is above strength in solute
A solution is hypotonic
The solution is below strath in solute
On which side of a selectively permeable membrane does osmosis exert a pressure
On the hypertonic side
What happens during the process of facilitated diffusion
Molecules, such as glucose, that cannot diffuse across the cell membrane’s lipid bilayer on their own move through protein channels instead
Facilitated diffusion does not require the cell to use energy
True
The energy requiring process that moves the material across a cell membrane against a concentration difference is called
Active transport
Active transport always requires transport proteins during the process
True
The process of taking material into the cell by means of infoldings, or pockets, of the cell membrane. The pocket that results breaks loose from the other portion of the cell membrane and forms a vacuole
Endocytosis
“Cell eating” Extensions of cytoplasm surround a particle and package it within a food vacuole. The cell then engulfs it.
Phagocytosis
Cells releasing large amounts of material from the cell, the membrane of the vacuole surrounding the material fuses with the cell membrane, forcing the contents out of the cell
Exocytosis
During endocytosis what happens to the pocket in the cell membrane when it breaks loose from the membrane
Forms a vacuole within the cytoplasm
