Module 3 Flashcards
Name the function of the Golgi Apparatus
packaging proteins from the rough ER into membrane-bound vesicles (secretory vesicles or lysosomes)
Name the function of secretory vesicles
transport various types of proteins out of a cell for use in other parts of the body; releases proteins through membrane via secretion
Name the function of free ribosomes
dense granules of RNA and protein responsible for manufacturing proteins from amino acids; either fixed to ER or free in cytoplasm
Name the function of lysosomes
type of storage vesicle, acts as digestive system of the cell, contains enzymes to destroy damages organelles, kill bacteria, and break down other biomolecules
Name the function of the mitochondria
generates ATP, can self-replicate even if cell isn’t undergoing division
Name the function of the ER
continuation of cell’s nuclear membrane, site for synthesis, storage, and transport of proteins and lipid molecules; rough/granular (covered in ribosomes, site of protein synthesis) or smooth (lacks ribosomes, site of lipid and fatty acid synthesis)
Name the function of the cell membrane
regulates passage of substances in and out of the cell, detects chemical signals from other cells and forms physical links with adjacent cells
Name the function of centrioles
responsible for directing movement of DNA strands during cell division
Name the function of the nucleolus
dense body within nucleus containing specific DNA that produces RNA for ribosomes
If the cell membrane had no membrane spanning protein, what function would be lost?
the controlled movements of substances that do not readily diffuse across the membrane would be lost
If the cell membrane had no carbohydrate molecules, what function would be lost?
immune response of the cell would be affected
If the cell membrane had no cholesterol molecules, what function would be lost?
water soluble molecules would be able to permeate the cell membrane
If the cell membrane had no structural associated proteins, what function would be lost?
organelles may not be properly anchored to the intracellular side of the membrane
If the cell membrane had no enzyme associated proteins, what function would be lost?
catalytic reactions of the cell membrane would be lost
If the cell membrane had no phospholipids, what function would be lost?
membrane integrity would be lost as it composes the majority of the membrane
Are water-soluble substances or fat-soluble substances able to permeate the lipid bilayer?
water soluble substances (ions, glucose, urea, and most other molecules) cannot cross, while fat soluble substances (oxygen, CO2, steroid hormones) can
Name five functions of membrane proteins
Receptors - for attachment of chemical hormones/neurotransmitter
Enzymes - help with chemical reactions
Ion channels - allow water soluble substances in
Membrane-transport carriers - transport molecules across membrane
Cell-identity markers - identify cell to others, can stimulate immune system
Name five ways substances cross membranes
Endo/exocytosis Diffusion through bilayer Diffusion through protein channels Facilitated diffusion Active transport
Define/describe diffusion
the movement of molecules from an area of high concentration to low concentration
Name four factors affecting the rate of movement of substances through protein channels
Size of protein channels, charge on the molecule, electrochemical gradient of the molecule, and number of channels
Describe facilitated diffusion
water-soluble molecules attach to specific protein carriers and cause a change in the protein shape to pass through membrane, does NOT require ATP
Describe active transport
requires protein carriers that span the membranes and does require ATP because molecules move up instead of down their concentration gradient
Define osmosis
diffusion of water down its concentration gradient
Name three factors affecting osmosis
permeability of the membrane to solutes, concentration gradients of solutes, and pressure gradient across cell membrane
Define osmotic pressure
the tonicity of a solution across a membrane
Define tonicity
the ability of a solution to cause osmosis across a biological membrane
Define isotonic solution
has the same concentration as body fluids, no osmosis occurs
Define hypotonic solution
has a lower concentration than cellular fluids, osmosis into the cell, cell would swell
Define hypertonic solution
has a higher concentration than cellular fluids, osmosis out of the cell, cell would shrink
What is an osmole?
a unit to describe the number of osmotically active particles in a solution
Name two units used to describe the concentration of a solution
osmolality (# of osmoles/kg water) and osmolarity (# of osmoles/L solution)
Define resting membrane potential
the charge difference between the inside and outside of the cell, separated by a membrane (inside is more negative than outside), voltage is -70mV
Define equilibrium potential
the electrical potential that must be applies to the inside of the cell to stop the movement of that ion down its concentration gradient
Define equilibrium potential
the electrical potential that must be applies to the inside of the cell to stop the movement of that ion down its concentration gradient
Name two forces acting on ions and affecting their movement
chemical concentration gradient (moves from high to low concentration) and electrical gradient (moves towards area of opposite charge)
State the equilibrium potential for Na+ in a neuron
+60mV
State the equilibrium potential for K+ in a neuron
-90mV
State the equilibrium potential for Cl- in a neuron
-70mV
Name two functions of the Na+/K+ pump
small contribution to the resting membrane potential and maintaining constant cell volume
