Lecture 4 Flashcards
What is the Epineurium of a Nerve?
Binds Fasicles together to form a nerve
What is the Perineurium of a Nerve?
Connective tissue that forms fascicles
What is the Endoneurium of a Nerve?
Thin connective tissue, separates neurons from another.
What is a Fasicle?
Group of Neurons
What is Adipose Tissue?
Known as body fat, extends throughout your body.
How does the Plasma Membrane form Sheet-Like Structures?
- Forms a closed boundary.. select entry/exit (selective permeability)
- 2 layers thick (60 - 100 ohmstrong)
How does the plasma membrane consist mainly of phospholipids and proteins?
- 1:4 to 4:1 ratio… large variability
- Mitochondria…. 76% protein, 24% lipid (wide range)
- Plasma Membrane.. 50% to 50% composition.
- Some membranes contain carbohydrates.. glycoproteins
Plasma Membrane: hydrophilic and hydrophobic
- Spontaneous form of bilayer
- Barrier to the flow of polar molecules
Plasma Membrane: Protein Function Specificity
Channels, pumps, energy transducers, receptors
Plasma Membrane: Polarized Structures
Inside of cell is typically electronegative (at a resting state).. with respect to outside.
Approximately -60mV
Plasma Membrane: Fluid Structures
Two Dimensional solutions of oriented proteins and lipids
- Lipid Molecules: Diffuse Rapidly through membrane in the plane
- Lipids and proteins do not rotate in the membrane (glycoproteins do)
What does the Fluid Mosaic Model Impose?
Membranes are not rigid… phospholipids provide fluid motion
What are the four membrane protein features?
Transport/Attachment.. into and out of the cell
Signal Transduction.. external to internal cellular changes (i.e changing metabolism)
Larger than Lipids.. move slower through membrane (heavier)
Immobile Proteins.. anchored to cytoskeleton
What are examples of receptors?
- Insulin
- Epinephrine
What are examples of Enzymes?
- Na+/K+ AtPase (sodium/potassium pump)
What are examples of channels?
- Aquaporin (water channel)
What are examples of a Gated Channel?
- Na +
- K+
(spend most of their time in a closed state)
What are examples of cell identity?
- MHC proteins
- Immune System
What are examples of CAMs?
- Cell - Cell Adhesion Molecules
What is the structure of the plasma membrane?
- Thin film of lipid and protein molecules
- Dynamic, fluid structure
What are the 4 basic functions of Membrane Proteins?
- Transport (i.e, glucose in glycolysis)
- Enzyme Activity
- Signal Transduction (molecule binds to proteins IN membrane to change something in cell)
- Attachment/Recognition
What are Integral Membrane Proteins (transmembrane)
- Hydrophobic, non-polar amino acids.. forms alpha helixes, interacts with fatty acids
- Hydrophilic, polar amino acids… external/internal portion of membrane proteins
What are Peripheral Membrane Proteins?
- DO not interact with hydrophobic core of membranes
- Held to membrane surface.. hydrogen or ionic bonds
- Example: cytoskeleton, intracellular (provides framework inside of cell)
Where is more Na+ found in?
Extracellular fluid (outside)
Where is more K+ found in?
Intracellular Fluid (Inside)
Where is more Ca++ found in?
Found in extremely low concentrations inside the cell before activated.
What is resting membrane potential units?
mV
Where is there lower O2?
Intracellular
Where is there greater CO2?
Intracellular
What is the pH in the intracellular fluid?
7 (neutral)
What is the pH in the extracellular fluid?
7.4
