Biological Molecules: Structure of DNA and RNA

Question 1

What does the pentagon represent in the structure of a nucleotide?

Answer 1

Pentose sugar

Question 2

What does the rectangle represent in the structure of a nucleotide?

Answer 2

Base

Question 3

What does the circle represent in the structure of a nucleotide?

Answer 3

Phosphate group

Question 4

What bonds form between one nucleotides pentose sugar and another’s phosphate group?

Answer 4

Phosphodiester bond

Question 5

What bonds form between two nucleotide bases?

Answer 5

Hydrogen

Question 6

What are the 4 bases of DNA (full names)?

Answer 6

-Adenine
-Thymine
-Cytosine
-Guanine

Question 7

What are the 5 main features of the structure of DNA?

Answer 7

• Base sequences
• Large
• Double helix
• Sugar-phosphate backbone
• Hydrogen bonds between bases

Question 8

What are the function of bases sequences in DNA?

Answer 8

Store genetic material

Question 9

What is the function of DNA being large?

Answer 9

Massive amount of genetic information

Question 10

What is the role of DNA having a double helix structure?

Answer 10

Compact

Question 11

What is the role of DNA having sugar-phosphate backbones?

Answer 11

Stability and protection = reduces mutations

Question 12

What is the role of DNA having hydrogen bonds between its bases?

Answer 12

They can break and reform, allowing replication and protein synthesis

Question 13

Give three differences between eukaryotic DNA and prokaryotic DNA

Answer 13

1) Eukaryotic DNA contains exons and introns, prokaryotic DNA only has exons
2) Eukaryotic DNA is long and linear, prokaryotic DNA is short and circular
3) Eukaryotic DNA has chromosomes, prokaryotic DNA doesn’t

Question 14

In RNA what does uracil replace?

Answer 14

Thymine

Question 15

RNA has a _______-helix structure.

Answer 15

Single

Question 16

Give the two matching base pairs in DNA:

Answer 16

Adenine and Thymine
Cytosine and guanine

Question 17

Give the two matching base pairs in RNA:

Answer 17

Adenine and uracil
Cytosine and guanine

Question 18

Many nucleotides join together to form ______ chains.

Answer 18

Polynucleotide

Question 19

What is the sugar-phosphate backbone?

Answer 19

The chain of phosphates and sugars.

Question 20

What joins polynucleotide strands together?

Answer 20

Hydrogen bonds between bases.

Question 21

How many hydrogen bonds form between adenine and thymine?

Answer 21

Two

Question 22

How many hydrogen bonds form between cytosine and guanine?

Answer 22

Three

Question 23

Give 4 differences between the structure of DNA and RNA:

Answer 23

1) RNA has a ribose sugar, DNA has a deoxyribose sugar.
2) RNA has uracil instead of thymine, DNA has thymine.
3) RNA’s nucleotides form a single polynucleotide strand, DNA’s nucleotides from a double polynucleotide strand.
4) RNA strands are much shorter than most DNA polynucleotides.

Question 24

What is a phosphodiester bond?

Answer 24

A covalent bond between two nucleotides, resulting in a condensation reaction.