HW #8 - AP Biology Period 4 Liem Nguyen #22 10/4/09...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
AP Biology Period – 4 Liem Nguyen #22 10/4/09 Homework #8 (091009): Chapter 7 (due Friday 091009 ) Total points: 20 for Attempt on all questions ONE Concept Map: 10 points Objectives 1. Explain why phospholipids are amphipathic molecules. Phospholipids are amphiphatic molecules because they have both a hydrophilic region and a hydrophobic region. 2. Explain what freeze-fracture techniques reveal about the arrangement of proteins in membranes. Freeze-fracture techniques split a membrane along the middle of the phospholipid bilayer. When the halves of the membrane are viewed in the electron microscope, the interior shows the arrangement of proteins in the membranes. 3. Describe the fluidity of the components of a cell membrane and explain how membrane fluidity is influenced by temperature and membrane composition. The phospholipids of the cell membrane move laterally, and unsaturated hydrocarbon tails keep the molecules of the cell membrane from packing together, enhancing its fluidity. Membrane remains fluid as temperature decreases until the phospholipids settle into closely packed arrangements, solidifying the membrane. 4. Explain how cholesterol resists changes in membrane fluidity with temperature change. Cholesterol resists changes in membrane fluidity that can be caused by changes in temperature. It reduces membrane fluidity at moderate temperatures by restraining phospholipid movement, and delays solidification at low temperatures by disrupting the packing of phospholipids. 5. Distinguish between peripheral and integral membrane proteins. Integral proteins penetrate the hydrophobic core of the lipid bilayer. Peripheral proteins are not embedded in the lipid bilayer, but loosely bounded to the surface of the membrane, to expose parts of the integral proteins. 6. List six major functions of membrane proteins.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

HW #8 - AP Biology Period 4 Liem Nguyen #22 10/4/09...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online