Cell/Cell Transport Flashcards
Cell theory
All living things are composed of cells
All cells come from pre-existing cells
Cells are the basic units of structure and function in an organism
Distinguish between the structures of prokaryotic and eukaryotic cells.
Eukaryotic cells are cells containing membrane-bound organelle Mitochondria present
prokaryotic cells do not have any membrane-bound organelles Mitochondria absent
Describe the structure of a plasma membrane
consists of both lipids and proteins. The fundamental structure of the membrane is the phospholipid bilayer
relate these parts to the functions of the plasma membrane.
LIPIDS- As structural components of the plasma membrane, lipids are responsible for contributing to membrane tension, rigidity, and overall shape.
PROTEINS-
Plasma membrane proteins that are exposed on the cell surface have important biological functions, such as signaling into and out of the cells, ion transport, and cell-cell and cell-matrix interactions.
Passive Transport
the movement of molecules across a membrane that does not require energy.
Diffusion
is the movement of molecules from an area of higher concentration to an area of lower concentration.
Osmosis
is the movement of water molecules across a membrane from an area of higher concentration to an area of lower concentration until equilibrium is reached.
Therefore, osmosis is a type of diffusion AND a type of passive transport —NO ATP REQUIRED.
Isotonic
The water and solute concentration are the same inside and outside of the cell. Water goes in and out at the same rate.
Hypotonic
The water concentration is greater outside of the cell, the solute concentration is greater inside. Water flows into the cell.
Hypertonic
water concentration is greater inside the cell, the solute concentration is greater outside. Water flows out of the cell.
Explain how animal and plant cells change when placed into hypertonic or hypotonic solutions.
If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink.
When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell.
Explain how transport proteins facilitate diffusion.
Facilitated diffusion is diffusion of molecules across a membrane that requires assistance by certain proteins called “carrier proteins”.
Carrier proteins help molecules move from a higher concentration to a lower concentration that are too large to freely pass through the membrane.
Compare and contrast active transport and facilitated diffusion.
Active transport is an active process meaning it requires the use of ATP, whereas facilitated diffusion is a passive process meaning it does not need ATP
Exocytosis
Cells can release substance when a vesicle’s membrane fuses with the cell’s membrane
Endocytosis
Cells can take in materials by the membrane indenting and pinching off a vesicle inside the cytoplasm
aquaporin
a hole for water to go through- lets water through freely. discovered by chance in 1992 by Peter Agre and his colleagues at the Johns Hopkins University in Baltimore,
Phagocytosis
Solids (Example: An amoeba eating)
types of endocytosis
Pinocytosis
Liquids
types of endocytosis
Receptor-mediated endocytosis
a means to import macromolecules from the extracellular fluid.
active transport
the movement of molecules across a membrane that does require energy.
