In-Class.Chapter-11

Which type of cell has an internal membrane creating intracellular compartments?

• Eukaryotic Cell

• Prokaryotic Cell

Why is the membrane in constant movement?

Answer explanation

The bilayer is made of many different phospholipids that are constantly in motion!

(There is also a natural tendency to move to a preferable environment for the cell. )

Also also, it’s in a fluid do you really expect it to stay in the same place? Do you expect a rubber duck to stay standstill in water? No.

Why do you think a cell needs barriers against water via membrane?

hint: what is our cytosol/extracellular fluid composed of?

bingo word: osmosis

Answer explanation

To regulate the input and output within the cell, we don’t want viruses and hormones, willy nilly all the time do we?

Hint: The cytosol and extracellular fluid is primarily made up of water and free-floating molecules, we don’t want all of those in/out cells. (cytosol is the liquid portion of the cytoplasm)

Also, too much or too little water is bad (Rupture or Shrivel)

Match it! ft. Cholesterol

Answer explanation

Hot: Melt

Cold: Rigid

Organelle Function emerges with utilization of...

• Enzymes

• Specialized Membranes

• Energy

• Different Environments

• Proteins

Select the function of the membrane

• Cell Signal Receiving

• Facilitation

• Cell Signal Interpretation

• Movement/Expansion

Does the Membrane Interpret Cell Signals?

• yes

• no

What is more common, lateral diffusion or flip flop?

• Lateral Diffusion

• Flip Flop

Why do lipid rafts stay together?

• similar function

• similar shape

• phosphatidylcholine bonds

• Hydrophobic Interactions

Transmembrane surfaces are Hydrophobic imbedded in the membrane and Hydrophilic when in the exposed region; can you explain why?

Hint: Think about our membrane and its

environment

Answer explanation

The extracellular and intracellular environment of the cell is water rich. Therefore, the exposed transmembrane surface is Hydrophilic.

As to not react harshly with the Hydrophobic tails the imbedded surface is hydrophobic.