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Flashcards in Chapter 3 Deck (8)
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1

Describe the Plasma (cell) membrane

It surrounds the cell.

Made of proteins and lipids.

Composition and function can vary from one region of the cell to another.

2

What is the Unit Membrane?

Forms the border of the cell and many of its organelles.

Appears as a pair of dark parallel lines around the cell (when viewed with an electron microscope)

3

What is the function of the plasma membrane?

-Unit membrane at the cell surface.
- Defines cell boundaries
-Governs interactions with other cells.
-Controls passage of materials in and out of cell

4

Describe the intracellular face and the Extracellular face in relation to Plasma Membrane.

Intracellular face - side that faces cytoplasm

Extracellular face - side that faces outward

5

Describe Membrane Lipids

98% of molecules in plasma membrane are lipids

6

How do Phospholipids play a role in the Plasma Membrane?

75% of membrane lipids are phospholipids.

Amphiphilic molecules arranged in bilayer

Hydrophilic phosphate heads face water on each side of membrane

Hydrophobic tails - directed toward the center, avoiding water drift laterally from place to place.

Movement keeps membrane fluid

7

How does Cholesterol play a role in the Plasma Membrane?

20% of the membrane lipids

holds phospholipids still and can stiffen membrane

8

How do Glycolipids play a role in the Plasma Membrane?

5% of the membrane lipids

Phospholipids with short carbohydrate chains on extracellular face

Contributes to Glycoalyx - carbohydrate coating on the cells surface