A1.2: Nucleic Acids Flashcards
State the two primary functions of nucleic acids.
- Pass information between generations
- Code for protein production
State the two types of nucleic acids used in cells.
- DNA; Deoxyribonucleic acid
- RNA; Ribonucleic acid
Outline the meaning and implication of DNA being the genetic material of all living organisms.
DNA carries all the genetic information of all living organisms through generations
State why RNA viruses do not falsify the claim that all living things use DNA as the genetic material.
Viruses are not considered living organisms as they are not made of cells
List the three components of a nucleotide.
- Pentose sugar (Ribose/Deoxyribose)
- Nitrogenous base
- Phosphate group
Identify and label the carbons of a pentose sugar.
- starts at 0 from the top and increases sequentially in a clockwork direction
Draw the basic structure of a single nucleotide (using circle, pentagon and rectangle).
- 1C in pentagon connects nitrogenous base
- 5C in pentagon connects phosphate group
Define “backbone” as related to nucleic acid structure.
DNA and RNA have a backbone of repeating phosphate and sugar formed when nucleotides combine in a condensation reaction
Explain how nucleotides connect to form a nucleic acid polymer.
- A covalent bond forms between the phosphate group attached to the 5′ C of one deoxyribose sugar and the –OH group attached to the 3′ C of another sugar, releasing one molecule of water with the use of energy.
State the names of the nitrogenous bases found in DNA and RNA.
DNA:
- Thymine
- Adenine
- Cytosine
- Guanine
RNA:
- Uracil
- Adenine
- Cytosine
- Guanine
State a similarity and a difference between the nitrogenous bases.
Similarity:
- All contain Nitrogen atoms
Difference:
- Different molecular structures
Outline how the sequence of bases in a nucleic acid serves as a ‘code.’
- The order of different types of nucleotides arranged in DNA or RNA serves as a code for storing genetic info in all living organisms
Define gene.
A gene is a specific sequence of nitrogenous bases in DNA nucleotides that code for the making of a protein
Describe the condensation reaction that forms a polymer of RNA from RNA nucleotides.
- The 3’ C of the ribose sugar in one nucleotide links with phosphate group on the 5’ C of the ribose sugar in another nucleotide
- H is lost from the 3’ C (OH) and OH is lost from Phosphate group thus, forming H2O
Identify the monomer and polymer of an RNA molecule.
Monomer:
- Nucleotides
Polymer:
- RNA chain
Draw a short section of an RNA polymer (using circle, pentagon and rectangle)
- Pentose sugar is Ribose
- Same position of nitrogenous base and phosphate group
Describe the structure of a DNA double helix.
- two sugar-phosphate backbones hydrogen bond between the nitrogenous bases to create a double helix
Outline the complementary base pairing rule, including the type and number of bonds between bases.
- Only certain bases between RNA and DNA strand or within a DNA strand can match as a result of their structure and ability to create H bonds
- A = T (or U); Connected with 2 H bonds
- G = C; Connected with 3 H bonds
Define antiparallel in relation to DNA structure.
- Two different strands of the DNA double helix run in opposite directions; at each end, one strand is 5’ and the other is 3’
Compare and contrast the structures of DNA and RNA.
- both are nucleic acids
DNA:
- made of 2 strand of nucleotides connected in the middle at the bases via H bonds
- contains the bases: adenine, thymine, cytosine, guanine
- contains a deoxyribose sugar (H on 2C)
RNA:
- made of only 1 strand of nucleotides
- contains the bases: adenine, uracil, cytosine, guanine
- contains a ribose sugar (OH on 2C)
Compare and contrast the functions of DNA and RNA.
DNA:
- Pass information between generations of cels
- Codes for making RNA during transcription
RNA:
- Codes for making proteins during translation (mRNA, tRNA and rRNA involved)
Compare and contrast the location of DNA and RNA in prokaryotic and eukaryotic cells.
DNA (Eukaryotic):
- located in the nucleus
- due to endosymbiosis, can also be found in chloroplasts and mitochondria
DNA (Prokaryotic):
- Nucleoid
- Plasmids
RNA (Eukaryotic):
- made in the nucleus during transcription and transported to the cytoplasm for translation
RNA (Prokaryotic):
- Cytoplasm
Outline the role of complementary base pairing in maintaining the DNA sequence during DNA replication.
- enzyme DNA Polymerase III builds a new strand by reading the DNA template and adding the complementary DNA nucleotide
- Thus, replication builds 2 identical DNA molecules
Outline the role of complementary base pairing in transmitting the genetic code in transcription and translation.
- enzyme RNA Polymerase builds an RNA strand by reading the DNA template and adding the complementary RNA nucleotide
