Key Vocabulary Terms and Definitions:
Active Transport: __________________________________________________________________
Passive Transport: _________________________________________________________________
Concentration Gradient: ____________________________________________________________
Standards and Objectives:
The structure of the cell membrane allows it to be a selectively permeable barrier and maintain homeostasis. Substances that enter or exit the cell must do so via the cell membrane. This transport across the membrane may occur through a variety of mechanisms, including simple diffusion, facilitated diffusion, osmosis, and active transport.
BIO.1D Students will describe the structure of the cell membrane and analyze how the structure is related to its primary function of regulating transport in and out of cells to maintain homeostasis.
BIO.1D.1 - Plan and conduct investigations to prove that the cell membrane is a semi- permeable, allowing it to maintain homeostasis with its environment through active and passive transport processes.
BIO.1D.2 - Develop and use models to explain how the cell deals with imbalances of solute concentration across the cell membrane (i.e., hypertonic, hypotonic, and isotonic conditions, sodium/potassium pump).
Organisms require energy in order to perform life functions. Cells are transformers of energy, continuously utilizing a complex sequence of reactions in which energy is transferred from one form to another.
BIO.2 Students will explain that cells transform energy to drive cellular functions.
BIO.2.1 - Use models to demonstrate that ATP and ADP are cycled within a cell as a means to transfer energy.
Key Concept and Review: (I can statements) 1 = not able to at all; 5 = I can do this with 100% accuracy
I can explain how a cell utilizes its semi-permeable membrane to maintain homeostasis. Pre: ____
I can explain what semi-permeable mean. Pre: ____ Post: ____
I can differentiate between Active and Passive Transport. Pre: ____ Post: ____
I can differentiate between Hyper-, Hypo-, and Iso-tonic solutions. Pre: ____ Post: ____
Passive Transport - movement of substances across the plasma membrane without the use of the cell’s energy
(with the concentration gradient)
DIFFUSION – movement of substances across the plasma membrane from an area of high concentration to an area of low concentration
OSMOSIS – diffusion of water across the plasma membrane from areas of high concentration to areas of lower concentration (Hypo, Hyper, Iso)
FACILITATED DIFFUSION – a carrier molecule embedded in the plasma membrane transports a substance across the plasma membrane following the high-to-low concentration gradient
Active Transport - movement of substances across the plasma membrane that requires the use of the cell’s energy and carrier molecules; substances are moving from an area of low concentration to an area of higher concentration (against the concentration gradient)
ENDOCYTOSIS – large particles are brought into the cell
EXOCYTOSIS – large particles leave the cell
Homeostasis - internal equilibrium; the plasma membrane regulates what enters and leaves the cell; a selectively permeable membrane only allows certain substances to pass through