Cholesterol

Question 1

What is cholesterol?

Answer 1

Lipid that can be distinguished by its characteristic four ring structure

Question 2

What types of cells have cholesterol?

Answer 2

eukaryotes

Question 3

What does cholesterol do in the cell membrane?

Answer 3

modulates the membrane fluidity
by making the membrane:

Less fluid at warmer temperatures

More fluid at colder temperatures

Cholesterol does this by binding adjacent
phospholipids together.

Question 4

When temperatures rise, the cholesterol

Answer 4

prevents rips in the membrane from
occurring by holding the phospholipids
together.

Question 5

When temperatures lower, the

cholesterol

Answer 5

prevents the membrane from freezing solid, by acting as a spacer between the phospholipid molecules.

Question 6

What types of cells have cholesterol?

Answer 6

found in high quantities in animal cells

Question 7

Why is cholesterol Cholesterol found in high

quantities in animal cells?

Answer 7

because animal cells don’t have a cell wall to maintain their structure, but still need to be flexible (fluid).

Question 8

Describe the structural placement of cholesterol within the cell membrane

Answer 8

Cholesterol fits between phospholipids in the cell membrane with its hydroxyl (-OH) group, by the heads

and the hydrophobic rings by the tails

Question 9

Cholesterol of cold blooded animals vs warm

Answer 9

Cold blooded animals (who can’t regulate body temperatures) tend to have more cholesterol than warm-blooded.

Question 10

Membranes must be fluid enough…

Answer 10

• for the cell to move

- for the required substances to move across them

Question 11

Membranes if too fluid…

Answer 11

won’t be able to regulate effectively what substances move in and out (think of holes or rips occurring in the
membrane).