UNCW Bio 201 Exam 2 UPDATED ACTUAL Exam Questions and CORRECT Answers

UNCW Bio 201 Exam 2 UPDATED
ACTUAL Exam Questions and CORRECT
Answers
Amphipathic Macromolecules - CORRECT ANSWER - Both hydrophilic and hyrdrophobic



Examples of Amphipathic Macromolecules - CORRECT ANSWER - 1. Phospholipids
2. Proteins in a membrane


Membrane Characteristics - CORRECT ANSWER - A. Membranes form spontaneously
B. Membrane structure is tightly controlled by cells.
We call the resulting structure a fluid mosaic.
1. 2 semifluid leaflets of lipids
2. 2 classes of proteins with numerous functions
3. Carbohydrates face the outside of the cell
C. Membrane "mosaic" structure enables
membrane function, and membrane have a
lot of functions to perform!


Hydrophobic Interactions - CORRECT ANSWER - cage-like structure of water
forms around hydrophobe


Step 1 of membrane fluidity - CORRECT ANSWER - Step 1. Hydrophobic exclusion pushes
fatty acids tails of phospholipids together


Step 2 of membrane fluidity - CORRECT ANSWER - H-bonds and
hydration spheres form
between water & the

, hydrophilic heads.


Step 3 of membrane fluidity - CORRECT ANSWER - van der Waals
interactions among the
hydrophobic portions of
molecules determines
membrane fluidity.


Relationship between fluidity and Van der Waals forces - CORRECT ANSWER - More van
der Waals
equals less fluidity.


Leaflet - CORRECT ANSWER - one half
(layer) of the
phospholipid bilayer


Van der Waals purpose in the cell membrane - CORRECT ANSWER - Hydrophobic portions
of membrane (tails of phospholipids)
molecules interact with
each other by van der
Waals forces. These
temporary bonds make
the membrane "fluid".


Two types of movement in one Leaflet - CORRECT ANSWER - 1. Laateral (side to side)
2. Rotational (Spin in a circle)


Protein required to move Phospholipids - CORRECT ANSWER - Flippase