chapter 3

Question 1

phospholipid bilayer

Answer 1

nonpolar fatty acid chains and polar heads (oriented outward as a result of their attraction to the polar water molecules)

Question 2

function of phospholipid bilayer (3)

Answer 2

• Separation of one aqueous environment from another
• selective barrier to the passage of molecules
• location for communication

Question 3

membrane structure of phospholipid bilayer

Answer 3

• flexible (fluid mosaic bc of cholesterol molecules)

- contains: proteins, carbohydrates, cholesterol

Question 4

what kind of proteins extend through the entire membrane

Answer 4

integral proteins

Question 5

functions of proteins in the membrane (3)

Answer 5

• transport molecules **
• allow cells to anchor to the extracellular matrix providing support
• act as receptors->communication

Question 6

endocytosis and exocytosis is helpful to to what to the surface area of the membrane

Answer 6

increase or decrease

Question 7

2 forms of endocytosis

Answer 7

1. membrane furrows inward (pinocytosis, receptor mediated endocytosis)
2. membrane extends outward around particle (phagocytosis )

Question 8

membrane furrows inward; pinocytosis

Answer 8

• form of endocytosis
• Endocytotic vesicle engulfs extracellular fluid
• Non-specific – any small molecule in the ECF will enter.

Question 9

membrane furrows inward; receptor mediated endocytosis

Answer 9

Designed to take up SPECIFIC molecules needed by the cell

Question 10

membrane extends outward around particle; phagocytosis

Answer 10

• form of endocytosis
• Cells engulf large particles and even other cells
• ‘Cellular eating’
• pac man

Question 11

exocytosis

Answer 11

• Important in releasing membrane-impermeable molecules produced by the cell
• -ex: protein hormones
• Replenishes the portions of the membrane lost in endocytosis.