#8: Cell Membrane

Question 1

Function

Answer 1

Allows cell to alter its shape and regulates movement of materials in and out

Question 2

Structure

Answer 2

Phospholipids, proteins, cholesterol, carbohydrates

Question 3

Phospholipids

Answer 3

Primary structure of membrane is phospholipid bilayer

Question 4

Proteins (2 Types)

Answer 4

Serve as variety of functions; membrane transport, hormone receptors, attaching membrane to cytoskeleton

Peripheral protein: found on surface of membrane

Integral: pass through membrane and embedded in lipid bilayer

Question 5

Cholesterol

Answer 5

Has hydrophilic and hydrophobic components

Helps keep membrane fluid-like and provides stability

Part of steroid ring closely attached to part of fatty acid on near phospholipid, which helps slightly immobilize outer surface of membrane and make it less soluble to small water-soluble molecules

Without it, membrane be too fluid, not firm enough, too permeable at high temp

At low, it helps separate phospholipids so fatty acid can’t come together and crystallize

Prevents extremes

Question 6

Carbohydrates

Answer 6

Oligosaccharides link to lipid and protein components on exterior of membrane

Play role in cell recognition and cell-cell interactions

Question 7

Fluid Mosaic Model

Answer 7

Used to describe cell membrane

Fluid - able to flow and alter shape freely
Mosaic- made up of many components