Nucleic Acids & Central Dogma
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Questions and Answers

What prevents the translation of mRNA into protein?

  • Ribose
  • Small RNAs (correct)
  • Nucleoside triphosphate
  • DNA polymerase

What type of reaction catalyzes nucleotide addition in nucleic acids?

  • Oxidation reaction
  • Condensation reaction (correct)
  • Reduction reaction
  • Hydrolysis reaction

Which of the following statements about DNA and RNA is FALSE?

  • DNA contains uracil instead of thymine. (correct)
  • DNA has deoxyribose sugar.
  • RNA is usually single stranded.
  • RNA is typically shorter than DNA.

During nucleic acid polymerization, nucleotides are added to which end of the growing strand?

<p>3’ end (D)</p> Signup and view all the answers

Which base pairs with adenine in RNA?

<p>Uracil (C)</p> Signup and view all the answers

What is the role of DNA polymerase in DNA synthesis?

<p>To catalyze the addition of nucleotides (D)</p> Signup and view all the answers

What type of bond occurs between complementary DNA bases?

<p>Hydrogen bond (D)</p> Signup and view all the answers

What distinguishes the sugar in RNA from that in DNA?

<p>RNA contains ribose while DNA contains deoxyribose. (C)</p> Signup and view all the answers

What defines the primary structure of nucleic acids?

<p>The linear sequence of nucleotides along the strand (B)</p> Signup and view all the answers

Which of the following structures corresponds to RNA's secondary structure?

<p>Pseudoknot (D)</p> Signup and view all the answers

What represents the quaternary structure in nucleic acids?

<p>The formation of ribosomes and spliceosomes from RNA (B)</p> Signup and view all the answers

Which pair of scientists are credited with determining the double helical structure of DNA?

<p>Francis Crick and James Watson (D)</p> Signup and view all the answers

Given that 30% of a DNA sequence is adenine (A), what percent of thymine (T) would be expected?

<p>30% (C)</p> Signup and view all the answers

How does the orientation of the DNA strands relate to their antiparallel nature?

<p>One strand runs 5' to 3' while the other runs 3' to 5' (A)</p> Signup and view all the answers

What is the primary structural unit of both DNA and RNA?

<p>Nucleotide (D)</p> Signup and view all the answers

Which nucleic acid is primarily responsible for storing genetic information?

<p>DNA (B)</p> Signup and view all the answers

What is the purpose of X-ray crystallography in the study of DNA?

<p>To uncover the helical structure of DNA (B)</p> Signup and view all the answers

What type of bond connects nucleotides in a nucleic acid strand?

<p>Phosphodiester bond (D)</p> Signup and view all the answers

What is indicated by the presence of a pseudoknot in RNA?

<p>It is a feature of the secondary structure (A)</p> Signup and view all the answers

Which nucleotide transition correctly demonstrates the process of DNA polymerization?

<p>dNTPn + dNMPn → dNMPn+1 + PPi (A)</p> Signup and view all the answers

In what direction is nucleic acid synthesized?

<p>5' to 3' (A)</p> Signup and view all the answers

Which of the following describes a significant difference between DNA and RNA?

<p>DNA has thymine; RNA has uracil. (D)</p> Signup and view all the answers

Which RNA type plays a role in the structure of ribosomes?

<p>rRNA (D)</p> Signup and view all the answers

What process describes the flow of information from DNA to RNA?

<p>Transcription (C)</p> Signup and view all the answers

What is the primary effect of heating purified DNA to 94°C?

<p>It induces denaturation of the DNA. (A)</p> Signup and view all the answers

What is the role of messenger RNA (mRNA) in gene expression?

<p>It carries genetic information from the nucleus to ribosomes. (C)</p> Signup and view all the answers

Which nucleotides act as an energy source in protein synthesis?

<p>GTP (A)</p> Signup and view all the answers

What feature of the DNA base sequences can be used to reveal evolutionary relationships?

<p>The specific base sequences. (C)</p> Signup and view all the answers

What is the meaning of semiconservative DNA replication?

<p>Each daughter DNA strand contains one original and one new strand. (C)</p> Signup and view all the answers

Which statement correctly describes the function of cyclic adenosine monophosphate (cAMP)?

<p>It is involved in signaling and gene expression. (C)</p> Signup and view all the answers

In the central dogma of molecular biology, what is the correct order of the processes?

<p>DNA Replication, Transcription, Translation (B)</p> Signup and view all the answers

What does the DNA base sequence provide information about?

<p>Evolutionary relationships among species. (D)</p> Signup and view all the answers

Which animal is most closely related to the Chimpanzee based on the DNA sequences described?

<p>Nomascus leucogenys (D)</p> Signup and view all the answers

Flashcards

Primary Structure of Nucleic Acids

The linear sequence of nucleotides (adenine, guanine, cytosine, and thymine) in a DNA or RNA molecule.

Secondary Structure of Nucleic Acids

The three-dimensional arrangement of a nucleic acid molecule, resulting from interactions between different parts of the molecule. This structure includes stems, loops, and pseudoknots, which are formed by base pairing between complementary nucleotides.

Nucleotide Sequence

Refers to the specific arrangement of nucleotides in a nucleic acid strand. It's like the order of letters in a word that dictates its meaning.

Double Helix

A helical structure formed by double-stranded DNA, where two antiparallel strands wind around each other.

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Base Pairing

The principle that in DNA, adenine always pairs with thymine (A-T), and guanine always pairs with cytosine (G-C).

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X-ray Crystallography

A technique that uses X-rays to determine the three-dimensional structure of molecules.

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DNA Replication

The process of DNA replication, where two identical DNA molecules are created from one original molecule.

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Chromatin

The interaction between DNA and histone proteins to form a compact structure called chromatin. This structure helps to organize and package DNA within the nucleus.

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DNA

Deoxyribonucleic acid, a nucleic acid that stores genetic information in all living organisms and some viruses.

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RNA

Ribonucleic acid, a nucleic acid involved in protein synthesis and other cellular processes.

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Nucleotide

The basic structural unit of nucleic acids, consisting of a sugar molecule, a phosphate group, and a nitrogenous base.

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Nucleoside

A nucleotide without a phosphate group. It consists of a sugar and a nitrogenous base.

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Phosphodiester bond

A covalent bond that links nucleotides together in a nucleic acid chain, formed between the phosphate group of one nucleotide and the sugar of the next.

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DNA Polymerization

The process of synthesizing a new DNA strand by adding nucleotides to a pre-existing DNA strand using a specific enzyme.

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Central Dogma

The flow of genetic information from DNA to RNA to protein.

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Complementarity of base pairing

A characteristic feature of DNA and RNA where specific base pairs form hydrogen bonds: adenine (A) with thymine (T) or uracil (U), and guanine (G) with cytosine (C).

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Small RNAs (miRNA & siRNA)

Small RNA molecules that play a crucial role in regulating gene expression, particularly in cell differentiation and development. They can bind to specific mRNA molecules and prevent their translation into proteins.

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What is nucleic acid?

A type of nucleic acid that consists of a chain of nucleotides linked together by phosphodiester bonds. It plays a vital role in the storage, transmission, and expression of genetic information.

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What is a nucleotide?

The basic building blocks of nucleic acids like DNA and RNA. Each nucleotide is composed of three parts: a sugar molecule (deoxyribose in DNA or ribose in RNA), a phosphate group, and a nitrogenous base.

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What is deoxyribose?

The sugar molecule found in DNA, a variant of ribose with one less oxygen atom.

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What is nucleic acid polymerization?

The process of linking nucleotides together to form a nucleic acid strand. It involves a condensation reaction that forms a phosphodiester bond between the 3’ hydroxyl group of one nucleotide and the 5’ phosphate group of the next nucleotide.

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What is DNA polymerase?

An enzyme responsible for synthesizing DNA strands. It adds nucleotides to the 3’ end of a growing DNA chain, reading the template strand to ensure accurate base pairing.

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What is the 5' end of a nucleic acid strand?

One of the two ends of a nucleic acid strand, where a phosphate group is attached to the 5’ carbon of the sugar molecule.

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What is the 3' end of a nucleic acid strand?

One of the two ends of a nucleic acid strand, where a hydroxyl group is attached to the 3’ carbon of the sugar molecule.

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DNA Denaturation

DNA is heated to a high temperature (94°C) to separate the two strands. This process is essential for DNA replication and PCR.

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Messenger RNA (mRNA)

A type of RNA that carries genetic information from DNA to ribosomes, where proteins are synthesized.

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Transcription

The process of copying genetic information from DNA to mRNA.

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Translation

The process of translating the genetic code in mRNA into a sequence of amino acids, forming a protein.

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DNA Base Sequence and Evolution

The sequence of nucleotide bases in DNA or RNA can reveal evolutionary relationships between different species.

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cAMP

Cyclic adenosine monophosphate, a second messenger involved in various cellular functions including signal transduction and gene expression.

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Study Notes

Nucleic Acids & Central Dogma

  • Nucleic acids store genetic information. DNA is deoxyribonucleic acid, found in bacteria, archaea, eukaryotes, and some viruses (like chickenpox, HPV, and HIV). RNA is ribonucleic acid, also found in some viruses (like influenza, poliovirus, and HIV)
  • DNA's structural unit is a nucleotide. RNA's structural unit is also a nucleotide. These differ in the sugar (deoxyribose vs ribose) and one of the nitrogenous bases (thymine vs uracil).
  • DNA polymerization occurs from the 5’ to 3’ direction, with a new nucleotide added to the 3’ end.
  • Nucleotides polymerize via phosphodiester linkages. This forms a condensation reaction.
  • DNA polymerase is responsible for the catalysis of DNA polymerization
  • dNMP + dNTP → dNMPn+1 + PPi.
  • Complementary base pairing: A pairs with T (in DNA) or U (in RNA) and C pairs with G. This pairing uses hydrogen bonds.
  • DNA has 4 structural levels: primary, secondary, tertiary, and quaternary.
  • Scientists involved in discovering DNA's structure include Oswald Avery, Erwin Chargaff, Rosalind Franklin, Maurice Wilkins, James Watson and Francis Crick.
  • DNA is used to estimate evolutionary relationships.
  • Special nucleotides, such as ATP (adenosine triphosphate), GTP (guanosine triphosphate), and cAMP (cyclic adenosine monophosphate), have other important functions like energy, signaling, and protein synthesis.
  • RNA and DNA differ in the type of sugar (deoxyribose vs ribose), and one base (thymine vs uracil). RNA is typically single-stranded, while DNA is typically double-stranded.
  • Information flows from DNA (genes) to RNA to protein.
  • The central dogma explains how information flows from DNA to RNA to protein.
  • Small RNAs regulate gene expression and are involved in cell differentiation and development. These molecules can control the expression of mRNA.
  • The DNA double helix has a sugar-phosphate backbone and bases (A, T, C, and G) inside. They run antiparallel (opposite directions).
  • DNA and RNA differ in their primary, secondary, and tertiary structures.
  • During DNA replication, identical copies of DNA are made. This is a semi-conservative process.
  • Both DNA and RNA contain nucleotides with bases, sugars, and phosphates which are connected by phosphodiester bonds.
  • Different levels of nucleic acid structure (primary, secondary, tertiary and quaternary) exist, each describing the organization at varying scales. For example, chromatin is the quaternary structure of DNA, while helical structures are examples of tertiary structure.

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Description

Explore the fascinating world of nucleic acids and the Central Dogma of molecular biology. This quiz covers key topics such as DNA and RNA structure, nucleotide polymerization, and the role of DNA polymerase in genetic information storage. Test your knowledge on how these vital molecules contribute to life.

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