Biology 213: Cell Structure and Fun<wbr>ction - Exam 2

The amphipathic nature of phospholipid is

Determined by fatty acid composition

Important in membrane structure

Polar but not nonpolar

Hydrophilic but not hydrophobic

C and d

Which of the following statements about lipids is FALSE?

Fats and oils are composed of three fatty acid tails plus a glycerol

Unsaturated fatty acids have 'kinks' and tend to be liquids in room temperature

Saturated fatty acids have many double bonds between the carbon atoms

In animals, fats are important in thermal insulation

Cholesterol is an important steroid in membranes

All of the following are true EXCEPT

GTP is a nucleotide used as an energy source in protein synthesis

A nucleotide is composed of pentose sugar, a nitrogenous base, and phosphate group

Nucleic acids always grow in a 5'-to-3' direction

The strands that make up a DNA molecule run in opposite directions

A DNA molecule is partially replicated but completely transcribed

Which of the following are true?

In polynucleotides, the 'backbone' is composed of alternating sugar and phosphate groups

DNA has ribose sugar, whereas RNA has deoxyribose sugar

Cytosine, uracil, and thymine are purines while adenine guanine are pyrimidines

The bases in nucleosides are always double ringed purines

In DNA, one strand is held to the other by phosphodiester bonds

Biology 213: Cell Structure and Function - Exam 2