General Biology II Exam 2 Part 2

Front

What are the three components of a nucleotide?

Back

1) Nitrogenous Base

2) Ribose Sugar

3) Phosphate Group

Front

What is the difference between a ribonucleotide and a deoxyribonucleotide?

Back

• - Ribonucleotides have ribose as the sugar

• - Deoxyribonucleotides have deoxyribose (no oxygen on the 2' carbon)

Front

Which type of nucleotide is used in RNA and which in DNA?

Back

• - RNA uses ribonucleotides

• - DNA uses deoxyribonucleotides

Front

What is a polynucleotide?

Back

A polymer made of many nucleotide monomers linked together.

Front

How are nucleotides linked in a polynucleotide?

Back

By phosphodiester bonds between the 3′ carbon of one sugar and the 5′ phosphate of the next.

Front

What is the sugar-phosphate backbone?

Back

A repeating chain of sugars and phosphate groups that forms the structural framework of the strand.

Front

What does 5′ to 3′ orientation mean?

Back

A polynucleotide has direction: it starts at the 5′ carbon end and grows by adding nucleotides to the 3′ carbon end.

Front

What is complementary base pairing in nucleic acids?

Back

• - A pairs with T (or U in RNA)

• - G pairs with C

Front

What type of bond holds base pairs together?

Back

Hydrogen bonds hold the nitrogenous bases together.

Front

How many hydrogen bonds form between each base pair?

Back

• - A–T pairs form 2 hydrogen bonds

• - G–C pairs form 3 hydrogen bonds