Nucleic Acids and the RNA World

Question 1

If you have a polymer with 10 A bases followed by 10 C bases and the strand bonds to another strand with 20 T bases, how would the stand be different than normal?

Answer 1

The width of the DNA double helix would vary along the length of the strand

Question 2

Which carbon does the phosphate group bond to on the sugar?

Answer 2

5

Question 3

Which carbon does the nitrogenous base bond to on the sugar?

Answer 3

1

Question 4

Why does G not pair with T and A pair with C?

Answer 4

They cannot form as many hydrogen bonds as A-T and G-C pairs

Question 5

What is the structural feature that allows DNA to replicate?

Answer 5

Complimentary pairing between the nitrogeneous bases

Question 6

RNA world hypothesis

Answer 6

RNA both stored genetic information and catalyzed its own replication

Question 7

3 components of a nucleotide

Answer 7

1. phosphate group
2. 5 carbon sugar
3. nitrogenous base

Question 8

What is the central component of the nucleotide?

Answer 8

sugar

Question 9

Difference between ribose and deoxyribose

Answer 9

Deoxyribose contains one less oxygen on its 2 position of the sugar

this hydroxide on the 2 of ribose makes it much more reactive and less stable

Question 10

Purines

Answer 10

adenine and guanine

both contain 9 rings (larger)

Question 11

Pyrimindines

Answer 11

cytosine, uracil, thymine

contain 6 rings

Question 12

How do nucleotides polymerize?

Answer 12

Via condensation

reactions between hydroxyl on the sugar of one nucleotide and phosphate on another nucleotide

Question 13

What does the condensation reaction create?

Answer 13

Phosphodiester linkage (covalent)

H20 is released

Question 14

5’ end

Answer 14

contains an unlinked 5’ phosphate

Question 15

3’ end

Answer 15

contains an unlinked 3’ hydroxyl (sugar)

Question 16

Which end are nucleotides added to in growing chain?

Answer 16

3’ end

this makes sense because the 3’ end contains the central sugar from which things are attatched

Question 17

Why is polymerization not spontaneous?

Answer 17

It requires an input of energy

Question 18

How is polymerization catalyzed?

Answer 18

the creation of activated nucleotides (ATP)

3 phosphates are all negatively charge and thus they have a strong repel force

Question 19

What is the backbone of nucleic acids?

Answer 19

Sugar-phosphate backbone

Question 20

What did Franklin and Wilkins tell us?

Answer 20

showed that the pattern of the molecule was probably helical

Question 21

Chargaff’s rule

Answer 21

the number of purines in a given molecule is equal to the number of pyrimidines

Question 22

What type of bonds form between nitrogenous bases?

Answer 22

Hydrogen

Question 23

Antiparallel

Answer 23

two strands of DNA must be oriented in opposite directions

Question 24

What do the negatively charged phosphates make DNA?

Answer 24

Hydrophillic overall

Question 25

DNA grooves

Answer 25

allow proteins to bind

Question 26

What makes DNA twist?

Answer 26

hydrophobic interactions

vander der Waals interactions

Question 27

Tertiary structure of DNA

Answer 27

normally wraps around proteins called histones

Question 28

DNA copying steps

Answer 28

NEED TO LEARN

Question 29

paradox of DNA

Answer 29

its orderliness and stability makes it great at storing information but also make it a bad catalysis

therefore, RNA is preferred to be the first self-replicating molecule

Question 30

How is secondary structure of RNA different?

Answer 30

It folds with the same strand

it does not have a complementary strand

Question 31

Hairpin

Answer 31

this occurs in the loop of RNA where there are unpaired bases because of the single strand secondary structure of Rna

Question 32

RNA’s versatility

Answer 32

RNA can fold into many 3D shapes, which makes it more versatile than DNA

Question 33

Ribozymes

Answer 33

RNA enzymes that help catalyze reactions

similar to protein enzymes