chapter 3: cells Flashcards
1
Q
plasma membrane
A
outer boundary of cell
acts as selectively permeable layer
2
Q
cytoplasm
A
intracellular fluid packed with organelles
3
Q
nucleus
A
controls the cellular activities
4
Q
what includes interstitial fluid, blood plasma, and cerebrospinal fluid
A
extracellular fluid (EMF)
5
Q
integral proteins are…
A
firmly inserted into the lipid bilayer
have both hydrophilic and phobic regions
6
Q
peripheral proteins are…
A
not embedded, but attach loosely to integral protein
or have hydrophobic region to anchor them
7
Q
glycocalyx
A
provides identity to the molecule
8
Q
what tasks do membrane proteins contain (6)
A
- transport
- receptors signal for transduction
- enzymatic activity
- cell-cell recognition
- attachment to exoskeleton and ECMatrix
- cell-cell joining
9
Q
tight junctions
A
- impermeable junctions
- prevent molecule from passing between cells
10
Q
desmosomes
A
- anchoring junctions
- help keep cells from tearing apart
11
Q
gap junctions
A
- communicating junctions
- allow ions and small molecules to pass cell to cell
- important in heart and embryonic cells
12
Q
passive transport
A
- no energy needed (uses kinetic energy)
- substances move from high to low concentration
13
Q
active transport
A
- requires added energy (ATP)
- moves from low to high concentration
