SAT II Biology M : Lipids

Study concepts, example questions & explanations for SAT II Biology M

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Example Questions

Example Question #1 : Lipids

Phospholipids are an essential component of the phospholipid bilayer necessary to the cell.

Which of the following correctly represents a phospholipid subunit with the corresponding polarity?

Possible Answers:

Phosphate tail: polar

Fatty acid tail: nonpolar

Fatty acid head: nonpolar

Phosphate head: nonpolar

Fatty acid tail: polar

Correct answer:

Fatty acid tail: nonpolar

Explanation:

A phospholipid generally consists of a phosphate head (polar) and a fatty acid tail (non-polar).

Example Question #31 : Sat Subject Test In Biology

The phospholipid bilayer is critically important to the separation of the internal and external environment of the cell.

What drives the formation of the phospholipid bilayer?

Possible Answers:

The external environment pushes non-polar hydrophilic fatty acid tails to form the inner layer and the polar hydrophilic head groups to form the outer layer.

The external environment pushes non-polar hydrophobic fatty acid tails to form the inner layer and the polar hydrophobic head groups to form the outer layer.

None of these

The external environment pushes non-polar hydrophobic fatty acid tails to form the inner layer and the polar hydrophilic head groups to form the outer layer.

The external environment pushes non-polar hydrophilic fatty acid tails to form the inner layer and the polar hydrophobic head groups to form the outer layer.

Correct answer:

The external environment pushes non-polar hydrophobic fatty acid tails to form the inner layer and the polar hydrophilic head groups to form the outer layer.

Explanation:

The external hydrophilic environment attracts polar hydrophilic phosphate head groups to the exterior, while allowing non-polar hydrophobic fatty acids to remain shielded in the interior of what becomes the phospholipid bilayer.

Example Question #1 : Lipids

Lipids are made up of hydrocarbons linked to each other. 

A hydrocarbon involves an atom of carbon with how many hydrogen atoms bonded to it?

Possible Answers:

One

Three

Five

Two

Four

Correct answer:

Two

Explanation:

A hydrocarbon is made up of a carbon and two hydrogen atoms attached to it.

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