Lecture 4

Question 1

What is the Epineurium of a Nerve?

Answer 1

Binds Fasicles together to form a nerve

Question 2

What is the Perineurium of a Nerve?

Answer 2

Connective tissue that forms fascicles

Question 3

What is the Endoneurium of a Nerve?

Answer 3

Thin connective tissue, separates neurons from another.

Question 4

What is a Fasicle?

Answer 4

Group of Neurons

Question 5

What is Adipose Tissue?

Answer 5

Known as body fat, extends throughout your body.

Question 6

How does the Plasma Membrane form Sheet-Like Structures?

Answer 6

• Forms a closed boundary.. select entry/exit (selective permeability)
• 2 layers thick (60 - 100 ohmstrong)

Question 7

How does the plasma membrane consist mainly of phospholipids and proteins?

Answer 7

• 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

Question 8

Plasma Membrane: hydrophilic and hydrophobic

Answer 8

• Spontaneous form of bilayer
• Barrier to the flow of polar molecules

Question 9

Plasma Membrane: Protein Function Specificity

Answer 9

Channels, pumps, energy transducers, receptors

Question 10

Plasma Membrane: Polarized Structures

Answer 10

Inside of cell is typically electronegative (at a resting state).. with respect to outside.

Approximately -60mV

Question 11

Plasma Membrane: Fluid Structures

Answer 11

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)

Question 12

What does the Fluid Mosaic Model Impose?

Answer 12

Membranes are not rigid… phospholipids provide fluid motion

Question 13

What are the four membrane protein features?

Answer 13

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

Question 14

What are examples of receptors?

Answer 14

• Insulin
• Epinephrine

Question 15

What are examples of Enzymes?

Answer 15

• Na+/K+ AtPase (sodium/potassium pump)

Question 16

What are examples of channels?

Answer 16

• Aquaporin (water channel)

Question 17

What are examples of a Gated Channel?

Answer 17

• Na +
• K+
  (spend most of their time in a closed state)

Question 18

What are examples of cell identity?

Answer 18

• MHC proteins
• Immune System

Question 19

What are examples of CAMs?

Answer 19

• Cell - Cell Adhesion Molecules

Question 20

What is the structure of the plasma membrane?

Answer 20

• Thin film of lipid and protein molecules
• Dynamic, fluid structure

Question 21

What are the 4 basic functions of Membrane Proteins?

Answer 21

• Transport (i.e, glucose in glycolysis)
• Enzyme Activity
• Signal Transduction (molecule binds to proteins IN membrane to change something in cell)
• Attachment/Recognition

Question 22

What are Integral Membrane Proteins (transmembrane)

Answer 22

• Hydrophobic, non-polar amino acids.. forms alpha helixes, interacts with fatty acids
• Hydrophilic, polar amino acids… external/internal portion of membrane proteins

Question 23

What are Peripheral Membrane Proteins?

Answer 23

• DO not interact with hydrophobic core of membranes
• Held to membrane surface.. hydrogen or ionic bonds
• Example: cytoskeleton, intracellular (provides framework inside of cell)

Question 24

Where is more Na+ found in?

Answer 24

Extracellular fluid (outside)

Question 25

Where is more K+ found in?

Answer 25

Intracellular Fluid (Inside)

Question 26

Where is more Ca++ found in?

Answer 26

Found in extremely low concentrations inside the cell before activated.

Question 27

What is resting membrane potential units?

Answer 27

mV

Question 28

Where is there lower O2?

Answer 28

Intracellular

Question 29

Where is there greater CO2?

Answer 29

Intracellular

Question 30

What is the pH in the intracellular fluid?

Answer 30

7 (neutral)

Question 31

What is the pH in the extracellular fluid?

Answer 31

7.4