Chapter 1: Compartments Flashcards
What is the structure that defines each cell’s boundary?
plasma membrane
What is the principal function of membranes?
to act as a barrier to diffusion of most water-soluble molecules
The _________ _________ acts as scaffolding for certain proteins.
plasma membrane
BE ABLE TO IDENTIFY THE ORGANELLES!
..
What are the 2 components that all cellular membranes have?
a bilayer of polar lipid molecules and associated proteins
DEFINITION: general permeability barrier, because most water-soluble (polar) molecules cannot readily traverse its nonpolar interior.
lipid bilayer
-hydrophilic, polar head
-hydrophobic, non-polar tail
What 3 plant membranes have an inner and outer membrane?
nuclear envelope, chloroplast envelope, mitochondria
All basic types of cell membranes are _____________.
inherited
What are the 3 membrane inheritance rules?
- Daughter cells inherit a complete set of membrane types from their mother.
- Each potential mother cell maintains a complete set of membranes.
- New membranes arise by growth and fission of existing membranes.
The _____________ nature of membrane lipids allows for the spontaneous assembly of bilayers.
amphipathic
In reference to the size of their hydrophilic heads, what size heads do sterols have?
small
What are the 5 ways a phospholipid can move in the plane of the membrane/through the bilayer?
- Lateral diffusion
- Bobbing
- Flexion
- Rotation
- Flip-flop
Phospholipids move __________ in the plane of the membrane, but very __________ from one side of the bilayer to the other.
rapidly; slowly
What is the name for the phospholipid translator that flips a phospholipid from one side of the bilayer to the other?
flippase
Cells optimize the __________ of their membrane by controlling lipid composition.
fluidity
What are two things that affect the temperature of melting of some phospholipids?
- fatty acid chain length
- double bonds
High or Low Temp?
Long fatty acid chain
No double bond
high temp
High or Low Temp?
Short fatty acid chain
Double bond
low temp
Membrane proteins associate with __________ __________ in many different ways.
lipid bilayers
The __________-_________ membrane model predicts structural and dynamic properties of cell membranes.
fluid-mosaic
_________ ________________ leads to characteristic changes in plasma membrane lipid composition.
cold acclimation
What is another name for the Hechtian strands that connect the protoplasts to the cell wall in the plasma membrane?
arrowheads
The endomembrane system forms a ______________ network, the organizations of which changes during the cell cycle development.
dynamic
The classical literature distinguishes 3 types of ER membranes: What are they?
- rough ER
- smooth ER
- nuclear envelope
______ bodies off a smooth ER membrane; _______ bodies that bud from specialized rough ER
oil; protein
______________ ____________ mediate the transfer of newly synthesized secretory/storage/membrane proteins from the ER to the Golgi apparatus.
transport vesicles
_____ ________________ _____________ appear to mediate non-vesicular lipid transport between the ER and other membrane systems.
ER attachment domains
Plant golgi apparatus consists of dispersed golgi stack-golgi associated TGN (trans-golgi networks) units that exhibit a ____________ ______________ organization.
polar cisternal
The Golgi scaffold/matrix originates on ___________ buds and mediates ER-to-Golgi _______ vesicle transport.
COPII
The _________-most Golgi cistern give rise to TGN cisternae that sort and package Golgi products.
trans
The Golgi apparatus is a ________________ factory.
carbohydrate
DEFINITION: secretory vesicles derived from the TGN fuse with the plasma membrane, releasing their contents into the extracellular space.
exocytosis
DEFINITION: a process by which cells absorb external material by engulfing it with the cell membrane.
endocytosis
In the process of excess plasma membrane molecules being returned to the cytoplasm, endocytosis is mediated by ___________-_________ _______________ (_____) that contain membrane proteins and lipids.
clathrin-coated vesicles (CCVs)
