The flashcards below were created by user
on FreezingBlue Flashcards.
What is meant by cell polarity?
The cell has both an apical and basal membrane and these do not switch and can be quite different and unique
name 3 intercellular (lateral) cell surface specializations, give some functions
- Tight junctions - barrier
- Adhering junctions - anchor
- Communicating junctions - talking
describe in detail tight junctions
Found on membranes that are super close, essentially creates a super tight barrier that is impermeable
3 types of adhering junctions?
- Intermediate junction - belt like
- Desmonsomes - disk like
- Hemidesmosomes - disk like
What is anchored at adhering junctions?
are intermediate junctions as tight as tight junctions? Where do you find them in relation to the tight junctions?
- No but they have mechanical strength
- Below the tight junctions
WHat is the bonus of a desmosome?
Gives flexibility as compared to intermediate junction
What comes along with desmosomes? (used as anchor for other things)
Attachment plaque which is used to anchor filaments
What kind of cells would you expect to have lots of desmosomes?
Cells that are often stretched or undergo mechanical stress often
What is a hemidesmosome in comparison to a desmosome?
- A half a desmosome, only on one side, so often seen on the basement membrane specifically
- It helps connect to connective tissue
- Also has aattachment plaque but obviously only on one side
Purpose of gap junctions?
What kind of cells would we expect to see a lot of gap junctions in?
Cells that work together such as muscle cells`
Through a gap junction a molecule is able to skip the ECM and go from?
Cytosol to cytosol
We can recognize gap junctions under a microscope cause it looks like?
The membranes are super close and almost fused
What size roughly can fit through gap junctions?
Super small like no bigger than single amino acid
What is a terminal bar?
- Where the 2 membranes of the cell meet the lumen and cease to go in the same direction and splay off
- Occurs where lateral surface meets apical surface
- Essentially area of junctional complexes that cannot be distinguished
Differnetiate between the function of cilia and the function of flagellum?
- Cillia are to move things on their surface
- Flagella move the actual cell itself
Describe cilia motion as compared to the motion of a flagellum?
- Cillia beat in one direction fold and reset
- Flagella beat in a circle or in a concentric pattern to cause thrust
Flagellum is made from what structure?
what is an axoneme
Microtunule based skeletonof cilia and flagella
describe the inside of a cilia?
2 central microtubules surrounded by 9 microtubules
What is a microvilli?
tiny tiny villi ontop of villi, they are essentially just membrane protrusions as compared to something that moves
Why does each microvilli have cell membrane and glycocalyx on it?
To hold digestive enzymes in for extra cellular digestion
What is inside a microvilli often?
What are stereocilia?
Don't beat look like cilia but essentially very long microvilli for very specific purposes such as hearing
What is the purpose of basal foldings?
active ion movement