Chapter 5- Membrane Structure and Function Flashcards
According to the mosaic model, plasma membranes are primarily made of
Phospholipids
cholesterol
proteins
What is rotational movement?
a phospholipid rotating on its axis to interact with its neighbors
What is lateral diffusion?
lateral movement of lipids and proteins found in the membrane
What is transverse diffusion?
The movement of a lipid or protein from one membrane surface to another
What is apoptosis?
Cellular suicide
What is the difference in electric potential between the interior and exterior of the cell called?
membrane potential
Which 3 factors contribute to membrane potential?
unequal distribution of ions
inability of anions to leave cell
potassium sodium pump
What is the usual range of membrane potential?
-40 mV to -90 mV
Disruption of the resting membrane potential causes?
muscle contraction
What are glycoproteins?
proteins with attached carbohydrate chains
Where are glycolipids located?
On the outside of the membrane
What are the types of membrane proteins?
channel carrier cell recognition receptor enzymatic junction
Which substances can diffuse through the membrane?
gases
hydrophobic molecules
small uncharged polar molecules
which molecules have the lowest permeabilty?
ions
What does moving down a gradient mean?
move from more crowded area to less crowded
What are 4 types of passive transport?
diffusion
filtration
facilitated diffiusion
osmosis
What is filtration?
physical pressure forces substance through membrane
What are 5 factors that affect diffusion rate?
steepness of gradient temp molecular size surface area membrane permeability
What is facilitated difussion?
movement down a gradient with help of protein channels
What is tonicity?
relative concentration of solutions that determines direction of diffusion
What is a hypotonic solution?
concentration of solute is lower than cell, causes cell to swell
What are the channels that allow water to diffuse through the membrane?
aquaporins
how are transport proteins activated?
by phosphate from ATP
What is the source of energy for secondary active transport?
The gradient that was created by primary active transport
What is endocytosis?
engulfing something and bringing it into the cell membrane
What are the types of endocytosis?
phagocytosis
pinocytosis-liquid/small particle`
receptor-mediated endocytosis
endo/exocytosis are what type of transport?
vesicular (active)
