Other Flashcards
- Describe the types of cell-cell junctions
o Adherens junctions111
“belts” (or zonulae adherens) that encircle each cell near its apical surface, binding that cell to its surrounding neighbors. Belts are held together by calcium-dependent linkages formed between the extracellular domains of cadherin molecules
- Describe the types of cell-cell junctions
o Tight junctions Locations111
very apical end of the junctional complex between adjacent epithelial cells.
- Describe the types of cell-cell junctions
o Desmosomes (differentiate from hemidesmosomes111
desmosomes- disc shaped adhesive junctions with cadherins that link the two cells across a narrow extracellular gap
The three-dimensional network of ropelike intermediate filaments provides structural continuity and tensile strength to the entire sheet of cells.
(Hemi attaches cells from the basal surface of epithelial cells to basement membranes
- Describe the types of cell-cell junctions
o Gap junctions purpose111
channels that connect the cytoplasm of one cell with the cytoplasm of the adjoining cell- where the plasma membranes of adjacent cells come very close to one another but connect via molecular pipelines
- Describe and differentiate between the four types of integral membrane proteins that allow for
cell-cell interactions
o Selectins111
Integral membrane glycoproteins that bind to carbohydrates on other cells
- Describe and differentiate between the four types of integral membrane proteins that allow for
cell-cell interactions
o Immunoglobulin superfamily111
Proteins with domains made of 70-110 AAs, that mediate calcium-independent cell–cell adhesion (mostly in immune cells)
- Describe and differentiate between the four types of integral membrane proteins that allow for
cell-cell interactions
o Integrins (again!)111
Integral proteins that bind to ligands to cause reactions in cells
- Describe and differentiate between the four types of integral membrane proteins that allow for
cell-cell interactions111
o Cadherins
The cadherins are a large family of glycoproteins that mediate Ca2+-dependent cell–cell adhesion and transmit signals from the ECM to the cytoplasm.
- Explain and describe how cell matrix adhesions differ from cell-cell interactions111
One connects cells to the matrix, the other connects cells to other cells
Tight junctions structure111
contact at intermittent points, where integral proteins meet.
Gap junctions structure111
Plasma membranes of adjacent cells come within about 3nm of each other, and the gap is spanned by very fine “pipelines,” or connexons that allow the passage of small molecules
Hemidesmosomes Function111
Adhesive structure at the basal surface of epithelial cells that cells to the underlying basement membrane.
Hemidesmosome structure111
dense plaque on inner surface of the plasma membrane with filaments coursing outward into the cytoplasm
-Describe how changes in delta G can alter movement across the plasma membrane, including
how charge can play a role in forming an electrochemical gradient111
- delta g=influx
+ delta G=efflux
If inside of cell is negative compared to outside and solute is +, influx is favored.
-Explain the differences in the various examples of ion transport proteins and how they are
controlled (PPT slides); These examples may need specifics, but also be able to apply them to
novel proteins – Understand the principles and significance of each
o KcsA channel111
The P region forms the lining of a
narrow selectivity filter because it
allows only the passage of K+ ions
with spacing of the backbone
carbonyl groups
Width of gate determines
specificity
* Accommodates dehydrated K+
* Can close and open via
conformation change
Diffusion of Ions through Membranes
Examplar: Bacterial KcsA K+ Channel
Gly-Tyr-Gly-Val-Thr
7
8
-Predict how changes in ion concentrations or membrane permeability affect membrane
potential.
o Nernst equation derived from Section 4.6 electrochemical gradient equation111
Delta G= Delta G0+RTlnQ
calculation of the reduction potential of a reaction
-Describe generally how myelination and
axon diameter influence the speed of nerve impulses.111
Axon diameter and myelination positively correlated with speed
-Compare excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs).111
Increase vs decrease possibility of postsynaptic action potential occuring
-Describe/draw how cells create connections using integrins to their surrounding ECM through
focal adhesions and hemidesmosomes
o Note the differences between cytoskeletal elements (actin and intermediate filaments
for now, this will come into play in the next unit too)555
Bind proteins of the cell surfaces to things like fibronectin. Cell surface proteins recognize RGD group on fibronextin
-Calculate the number of ATP generated by ATP synthase given starting materials (eg. Glucose or
38 molecules of ATP. (2 from glycolysis, 2 from Krebs cycle, and 34 ATP from the electron transport chain.
c subunits111
form a rotating ring within the membrane;
(Electron carrier) Iron-sulfur proteins- location111
ETC
o Na+/K+ pump111
moves three Na + ions out and two K + ions into the cell for each ATP hydrolyzed. The action of Na + -K + pump maintains a resting membrane potential of -30 mV to -70 mV in mammalian cells
o Ca2+-ATPase111
Removes calcium from the cell by binding to Ca2+ ions and using the energy from ATP hydrolysis to change its conformation, allowing the transport of calcium out of the cell or into the sarcoplasmic reticulum.
how many atp from long chain fatty acids,111
Each beta oxidative cut of the acyl-CoA molecule eventually yields 14 ATP molecules in oxidative phosphorylation. Krebs would produce 10 ATPs from Acetyl-CoA. 1 NADH makes 2.5 ATP, 1 FADH2 makes 1.5 ATP, both in ETC
the paired b subunits of the Fo base and the 𝛅δ subunit of the F1 head 111
form a peripheral stalk that holds the 𝛂𝛃α/β subunits in a fixed position;
and the a subunit 111
contains the proton channel that allows protons to traverse the membrane
the γ subunit ;111
runs through the core of the ATP synthase from the tip of F1 down to Fo to form a central stalk
the 𝛆ε subunit 111
helps attach the γ subunit to the Fo base
