3.1.5.1 Structure of DNA and RNA Flashcards Preview

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Flashcards in 3.1.5.1 Structure of DNA and RNA Deck (35):
1

DNA is made from which monomer?

Mononucleotides (or just nucleotides)

2

Name the 3 components of a nucleotide

Phosphate group

Pentose sugar

Organic base (containing nitrogen)

3

In DNA, which base complements guanine?

cytosine

4

In RNA, which base complements adenine?

uracil

5

In DNA, which base complements thymine?

adenine

6

Idenitfy the 5' and 3' carbon atoms of the deoxyribose molecule.

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Idenitfy the 5' and 3' carbon atoms of the deoxyribose molecule.

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7

Identify the molecule.

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Ribose

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8

In RNA, which base complements guanine?

cytosine

9

In DNA, which base complements cytosine?

guanine

10

In RNA, which base complements uracil?

adenine

11

Which atoms will react to join the two nucleotides?

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Which atoms will react to join the two nucleotides?

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12

What shape does a molecule of DNA take?

A double helix

13

In DNA, which base complements adenine?

thymine

14

DNA is a stable molecule because...

  • The phosphodiester backbone protects the chemically reactive base pairs.
  • C-G base pairs contain 3 hydrogen bonds, so the more C-G base pairs in a DNA molecule the more stable it is.
  • Interactive forces between base pairs add further stability ('base stacking')

15

How many hydrogen bonds are formed between Cytosine and Guanine in a DNA molecule?

3

16

Name the bond that forms between the 2 nucleotides of a dinucleotide.

Phosphodiester bond

17

What is the function of RNA?

To transfer genetic information from DNA to the ribosomes.

18

How is DNA adapted to carry out its function as a means of passing genetic information from generation to generation?

  • Very stable - rarely mutates
  • Hydrogen bonds between strands easy to separate for replication and protein synthesis.
  • Very long - carries a lot of genetic information.
  • Base pairs protected from chemical/physical forces by phosphodiester backbone.

19

Name the 3 Scientists who discovered the structure of DNA

James Watson

Francis Crick

Rosalind Franklin

20

Describe how are 2 DNA nucleotides form a dinucleotide

A condensation reaction occurs between the hydroxyl (OH) group on the 3' carbon of Deoxyribose on 1 nucleotide and the hydroxyl group of the phosphate group on another nucleotide.

21

In RNA, which base complements cytosine?

guanine

22

How many hydrogen bonds are formed between Adenine and Thymine in a DNA molecule?

2

23

How are the 2 strands of DNA that make up the double helix held together?

Hydrogen bonds between complementary organic bases

24

What is the function of DNA

To carry genetic information

25

Name the 2 nucleic acids

Deoxyribonucleic acid (DNA)

Ribonucleic Acid (RNA)

26

Identify the molecule.

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Phosphoric Acid

(phosphate)

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27

Name the organic bases that can become part of a DNA nucleotide

Adenine

Thymine

Cytosine

Guanine

28

The phosphate group, pentose sugar and organic base of a DNA or RNA nucleotide are joined through which type of reaction?

Condensation reaction

29

The phosphate group attaches to which carbon atom of a ribose or deoxyribose molecule when forming a nucleotide?

The 5' carbon atom (pronounced 5 prime)

30

Name the organic bases that can become part of a RNA nucleotide

Adenine

Uracil

Cytosine

Guanine

31

Identify the molecule.

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Deoxyribose

A image thumb
32

Describe how are 2 RNA nucleotides form a dinucleotide

A condensation reaction occurs between the hydroxyl (OH) group on the 3' carbon of Ribose on 1 nucleotide and the hydroxyl group of the phosphate group on another nucleotide.

33

Which type of bond are the arrows pointing at?

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Phosphodiester bond

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34

If the bases on one strand of DNA are TGGAGACT, determine the base sequence on the other strand.

ACCTCTGA

35

If 19.9% of the base pairs in human DNA are guanine, calculate the percentage that is Thymine. Show your reasoning.

30.1%

If 19.9% is guanine - 19.9% is cytosine as it is paired with it.

19.9 + 19.9 = 39.8%.

The remaining DNA is made from Adenine and Thymine, which is 60.2%. Thymine = 60.2% divided by 2 = 30.1%.