Lipids And Cell Membranes

Question 1

What defines a compound as a lipid?

Answer 1

Defined by function. Dissolved in organic solvent (not water)
Energy storage
structure
Information
Emulsifiers
Protective coating

Question 2

Membrane lipids include free fatty acids with chains of four to seven carbons. True or false.

Answer 2

True: long chain

Question 3

The average biological membrane is mostly just a phospholipid bilayer. True or false.

Answer 3

false

Question 4

Is the cell membrane rigid? Why?

Answer 4

Plasma membrane is fluid because of the unsaturated fats. This is caused by the double bond that creates a cis or trans configuration.

Question 5

What is the effect of cholesterol on lipid bilayer?

Answer 5

Steroid. Part of it can dissolve in water. Plays a role in cell communication. Is 10-25% of cell membrane. Manages the fluidity of the membrane

Question 6

What are the different types of protein that are associated with the cell membrane?

Answer 6

Transporter proteins: move stuff across membrane.

Question 7

The average biological membrane is fairly permeable to most hydrophilic substances. TF

Answer 7

True

Question 8

Category of Lipids

Answer 8

Isoprenoids
fatty-acid derived lipids
Steroids

Question 9

Cholesterol:

Answer 9

Makes membranes fluid at lower temperatures
Makes membranes rigid at higher temperatures.
Is a steroid
Is amphipathic, through small hydrophilic head.

Question 10

Which of the following do the enzymes aspartate tanscarbamoylase (ATC or ATCase) and glutamine synthetase have in common with one another?

Answer 10

Having non-michealis-menten kintics
Feedback inhibited by pathway end product
Quaternary structure
Upregulated by some compounds

Question 11

There are other means of enzyme regulation in addition to standard inhibition the most important biologically being allostery. What are others?

Answer 11

Covalent modificaiton
Regulatory subunits
Zymogen activation
Isozymes and expression.