Nucleic Acids and the Origin of Life

Question 1

Nucleic acids?

Answer 1

polymers specialized for the storage, transmission, and use of genetic information

Question 2

DNA and RNA full forms?

Answer 2

DNA = deoxyribonucleic acid
RNA = ribonucleic acid

Question 3

Parts of a nucleotide?

Answer 3

Nitrogenous base, phosphate group, sugar (ribose or deoxyribose)

Question 4

Triphosphates (ex. ATP)?

Answer 4

Store chemical energy in the form of three phosphate groups

Question 5

The 4 different Nitrogenous bases/DNA bases?

Answer 5

Adenine, Guanine, Thymine, Cytosine (Uracil - in RNA)

Question 6

Purines?

Answer 6

Double ring structures; Adenine and Guanine

Question 7

Pyrimidines?

Answer 7

Single ring structures; Thymine, Cytosine and Uracil (in RNA)

Question 8

Chemical difference between DNA and RNA

Answer 8

Presence of Uracil instead of Thymine in RNA

Question 9

Bonds in DNA and RNA?

Answer 9

Phosphodiester bonds

Question 10

How do purines pair with pyrimidines?

Answer 10

Through Hydrogen bonds

Question 11

Complementary Base Pairing?

Answer 11

A–T
C–G

Question 12

Difference between DNA and RNA?

Answer 12

RNA: Presence of Uracil; single stranded
DNA: Presence of Thymine; double stranded

Question 13

What type of helix does DNA typically form?

Answer 13

right-handed double helix (B-form DNA)

Depending on conditions, DNA can form Z-form and A-form helices as well.

Question 14

Grooves in DNA?

Answer 14

Due to the angle of the purines, the B-form helix has major and minor grooves.

Question 15

DNA is a _______ molecule

Answer 15

informational

Question 16

Central Dogma for Molecular Biology

Answer 16

DNA replication —> Transcription —> Translation

Question 17

Complete set of DNA in living Organisms

Answer 17

Genome

Question 18

Sequences of DNA that encode specific proteins

Answer 18

Genes

Question 19

Sources of Biological molecules?

Answer 19

1. Outer Space
2. Geophysical means (Earth origin)

Question 20

Chemical Evolution?

Answer 20

Conditions on primitive Earth led to formation of simple molecules (prebiotic synthesis); these molecules led to formation of life forms.

Question 21

Miller and Urey’s experiment?

Answer 21

Experiment with gases thought to have been present in Earth’s early atmosphere.
An electric spark simulated lightning as a source of energy to drive chemical reactions.
After several days, amino acids, purines, and pyrimidines were formed.

Question 22

What is thought to have evolved first?

Answer 22

RNA; Catalyzed its own replication and protein synthesis

Question 22

Riboenzymes?

Answer 22

Folded RNA molecules that can act as catalysts.
They can catalyze reactions on their own nucleotides as well as other molecules.

Question 23

Can metabolism and replication occur in dilute aqueous environments?

Answer 23

No; The compounds involved must have been concentrated in a compartment.

Question 24

How are living cells separated from their environment?

Answer 24

Living cells are separated from their environment by a membrane.

Question 25

Coenzymes?

Answer 25

‘e- taxis’ that transfer
electrons from one reaction
to another. Ex. NAD+ and FAD

Question 26

ATP?

Answer 26

Adenosine Triphosphate; Transfers energy from one reaction to another within cells