Vocabulary
Stability of the internal environment and the mechanisms that maintain that stability
Homeostasis
This type of diffusion involves the net movement of molecules from high to low concentration.
Ex. O2 and CO2
Simple Diffusion
In a _______________ solution the amount of water is lower than the cell’s cytoplasm.
–Net movement of water out of cell so the cell shrivels
Hypertonic Solution
______________ chemical signals affect the same cell that releases them.
Autocrine
______________ receptors are located inside a cell. Ligands for these signals are small and/or nonpolar so they can easily diffuse across the cell membrane to reach these receptors.
Intracellular
Sensory organ that receives the stimulus
Receptor
This type of diffusion uses a transport protein (channel or carrier) to aid in the movement of molecules from high to low concentration.
Ex. Polar molecules like Ca+2 and large molecules like glucose
Facilitated Diffusion
In a ______________ solution the amount of water is higher than the cell’s cytoplasm. Net movement of water into a cell, the cell swells
Hypotonic
_______________ chemical signals diffuse to nearby cells
Paracrine
_______________receptors are located on surface of the cell. Ligands for these signals are large and/or polar that cannot diffuse through the cell membrane
Membrane
An action that evokes a response
Stimulus
Diffusion of water from high to low concentration.
Ex. Water
Osmosis
In a ____________ solutions there is an identical water concentration to cell’s cytoplasm so the cell stays the same
Isotonic
________________ chemical signals require direct contact between the signaling cell and the receiving cell
Juxtacrine
When a ligand binds to the receptor protein, the bond is ______________ (therefore not strong) and is reversible.
noncovalent
When the output of a process is used as an input to control the behavior of the overall process itself, usually leading to inhibition of the process
Feedback inhibition
This pump uses energy to move molecules through a protein channel against the concentration gradient.
Ex. Na+/K+ Pump
Molecular pumps
A test tube of water containing 0.07 molar of glucose, holding a cell whose cytoplasm has a concentration of 0.05 molar glucose. What type of solution is this?
Hypertonic
Solutions with a high concentration of solute molecules (salt, sugar) will have a lower concentration of water molecules.
____________ are chemical signals that travels to distant cells.
Hormones
______________ can block the normal ligand to prevent communication.
Inhibitors
A sequence of events initiated by a signal that leads to a cellular response
Signal transduction pathway
_________________ uses energy and vesicles to move particles into the cell. Ex: White blood cells engulf bacteria for destruction
_________________ uses energy and vesicles to move particles out of the cell. Ex: Neurons secrete neurotransmitters for signaling
Endocytosis
Exocytosis
A test tube of water containing 0.03 molar of glucose, holding a cell whose cytoplasm has a concentration of 0.07 molar glucose. What type of solution is this?
Hypotonic
Solutions with a high concentration of solute molecules (salt, sugar) will have a lower concentration of water molecules.
______________ are molecules that bind to other molecules (receptor proteins) for signaling purposes.
Ligands
How is caffeine acting as an inhibitor to block cellular communication?
Caffeine is a large, polar molecule that binds to receptors on nerve cells in the brain
Its structure is similar to adenosine, which binds to receptors after activity or stress à feelings of drowsiness.
Caffeine binds to the same receptor, but does not activate it à a person remaining alert rather than feeling tired