Membrane Lipids and Proteins
Simple and Facilitated Diffusion
Active Transport
Endoplasmic Reticulum and Golgi Apparatus
Miscellaneous
100
What macromolecule is most common in the cell membrane?
Lipids, specifically phospholipids
100
In which direction does molecules of a concentration gradient flow?
Down the concentration gradient (High conc. -> low conc.)
100
Define osmolarity
The total solute concentration
100
What is the difference between the rough ER and the smooth ER?
The rough ER contains ribosomes on the cisternae
100
What role does this type of lipid have in our cells? *Also name the group this lipid belongs to*
Sphingoglycolipid
Role: Determines our blood type
200
Why is the cell membrane called the fluid mosaic model?
Fluid: The cell membrane is dynamic and moves while maintaining its structural integrity - hydrophobic-hydrophilic interactions between the components of the membrane and water keeps the cell membrane together
Mosaic: The cell membrane is made of many different molecules, such as proteins, carbohydrates, and lipids
200
What are the three types of transport across the membrane? Which takes energy and why?
Simple diffusion, facilitated diffusion, and active transport.
Active transport requires energy because it pumps molecules against the concentration gradient
200
What would happen to a cell if the extracellular fluid had a higher solute concentration?
The cell would shrink as water flows towards the area with greater solute concentration (hypertonic)
200
What are the 4 functions of the Rough ER?
1. Folding of proteins
2. Removal of misfolded proteins
3. Adding CHOs to proteins
4. Assembling complexes
200
What does amphipathic mean? Give an example.
Means a molecule that has both hydrophobic and hydrophilic characteristics
Example: phospholipid
300
What are Omega-3 fatty acids?
Unsaturated fatty acids with an alkene moiety at the 3rd C from the omega end
300
Which side of a cell is negative relative to the other?
The inside of the cell is relatively negative compared to the extracellular region (positive)
300
How many Na+ molecules and K+ molecules are moved in the Na+/K+ pump? In which direction?
3 Na+ out, 2 K+ in
300
How does the smooth ER carry out detoxification?
1. Cytochrome P450 (CYP) use a heme group to transfer an OH group to toxic molecules
2. Toxic molecules are now more hydrophilic (OH is polar)
3. Toxic molecules are flushed out by kidneys
300
What is the function of the Golgi Apparatus?
Process and package proteins and lipids from ER to other parts of the cell
400
What property of transmembrane proteins allows them to be embedded in the cell membrane?
The membrane-spanning domain is composed of hydrophobic residues, which has favorable interactions with the hydrophobic phospholipid tails
400
Give a specific example of facilitated diffusion.
GLUT1 transporter or aquaporins
400
What is the difference between direct and indirect active transport?
Direct: Uses ATP to create/maintain a concentration gradient by moving molecules from low concentration to high
Indirect: Uses the concentration gradient made by direct active transport to move another substrate along with it
400
What is the difference between the cis and trans Golgi network?
Cis-Golgi Network: Recieves vesicles from ER
Trans-Golgi Network: Leaves golgi apparatus to other areas
400
I'm going to point out a couple components of cell membrane... tell me what they are.
a. Blue blobs
b. Yellow hexagonal shapes
c. Green Y's
d. Blue Y's coming off some of the blue blobs
e. Orange ball with yellow tails 
a. Proteins
b. Cholesterol
c. Glycolipid
d. Sugars
e. Phospholipid
500
What are the three main lipid classes in the cell membranes, and what are they composed of?
1. Phospholipids: Two fatty acid tails, a glycerol, a PO4-, and an R group
2. Glycolipids: Sugar and a fatty acid tail
3. Sterols: Cholesterol covalently bonded w/ phospholipid
500
What are the differences between uniporters, symporters, and antiporters?
1. Uniporters: Proteins that move one type of molecule in one direction
2.Symporters: Proteins that move multiple types of molecules in one direction
3. Antiporters: Proteins that move multiple types of molecules in opposite directions
500
Why are active transport pumps called ATPases? Why is the transport of molecules considered a secondary function?
Active transport pumps all hydrolyze ATP to ADP + Pi, so they are called ATPases.
These proteins have evolved to break down ATP, the transport of molecules are just a secondary process that occurs alongside their primary function
500
What are the two types of glycosylation of proteins?
N-glycosylation: CHOs added to amino group of Asp side chain
O-glycosylation: CHOs added to OH group of Ser or Thr side chain
500
Name an example of Indirect Active Transport. Why is it indirect?
Na+/Glucose Symporter.
Indirect because takes advantage and uses the concentration gradient set up from Na+/K+ pump. Na+ naturally wants to go to lower concentration side so it does and drags glucose with it (glucose high concentration in cell but wants more) so active transport because glucose going from low to high concentration (against concentration gradient) but indirect because using the concentration gradient (Na+) set up from another pump that utilized ATP. Glucose going against its concentration gradient and Na+ going with its concentration gradient.