DNA

Question 1

How are nucleotides joined together?

Answer 1

Condensation

Question 2

How are the bonds between nucleotides called?

Answer 2

Nucleic Acid (DE: Nukleinsäuren )

Question 3

When is nucleic acid (DE: Nukleinsäuren) called RNA?

Answer 3

When the sugar part is ribose then the nucleic acid is called RNA. If the sugar part is deoxyribose this nucleic acid is called DNA.

Question 4

When is the nucleic acid called DNA?

Answer 4

The nucleic acid is called DNA when the sugar part is deoxyribose.

Question 5

What are pyrimidines (DE: Pyrimidin)?

Answer 5

Thymine, Uracil, Cytosin

They are the smaller ones.

Question 6

What are the purines (DE: Purin)?

Answer 6

Adenin, Guanin

They are the bigger ones.

Question 7

Explain the semiconservative replication

Answer 7

The semiconservative replication is when the new DNA molecule consists of one conserved strand plus one newly built strand.

The steps are as follows:

• double helix is untwisted
• hydrogen bonds between the bases are broken apart to unzip the DNA
• free DNA nucleotides are hydrogen-bonded onto the exposed bases according to the base-pairing rules
• covalent bonds are formed between the phosphate of one nucleotide and the sugar of the next to seal the backbone

Question 8

What are the base pairing rules?

Answer 8

In the DNA:

A (Adenine)/ T (Thymine)
“Apfel und Titi”

C (Cytosine) /G (Guanine)
“Cowboy und Gandalf”

Question 9

How are nucleotides bond together?

Answer 9

Nucleotides are bond together by hydrogen bonds.

Question 10

Describe the difference of RNA and DNA

Answer 10

• the sugar molecule that makes up the nucleotides is ribose (in RNA)
• the nitrogenous (stickstoffhaltig) base uracil is found instead of the oraganic base thymine(RNA)
• the polynucleotide chain is usually single-stranded (einzelstraengig)
• three forms of RNA molecule exist (mRNA, rRNA, tRNA)

Question 11

What are the base-pairing (Basenpaarung) rules for RNA?

Answer 11

A/U
“Apfel und Unterhose”

“C/G”
“Cowboy und Gandalf”

Question 12

What happnes to exposed DNA nucleotides?

Answer 12

If DNA are exposed free RNA nucleotides form complementary hydrogen-bonds with them and form a RNA chain→transcription

Question 14

Name the 3 forms of RNA

Answer 14

mRNA, rRNA, tRNA