BS Nursing Level 1: Biochemistry Nucleic Acids
37 Questions
4 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of base pairing occurs between A and T in DNA?

  • Three hydrogen bonds
  • Four hydrogen bonds
  • Two hydrogen bonds (correct)
  • One hydrogen bond

    • Which of the following statements about DNA double helix structure is correct?

  • The base pairs can vary in width
  • The strands run in the same direction
  • Each base pair consists of a purine and a purine
  • The strands are antiparallel (correct)

    • Which base pairs are considered complementary in DNA?

  • G-A and T-C
  • A-C and G-T
  • C-T and A-G
  • A-T and C-G (correct)

    • In the DNA model developed by Watson and Crick, how many base pairs are present per turn of the helix?

    <p>10 base pairs</p> Signup and view all the answers

    What is the role of hydrogen bonding in DNA?

    <p>It stabilizes the DNA double helix</p> Signup and view all the answers

    What is the defining factor for the nomenclature of nucleotides?

    <p>The number of phosphate groups</p> Signup and view all the answers

    Which nitrogenous base contains a methyl group?

    <p>Thymine</p> Signup and view all the answers

    What forms adenosine 5’ diphosphate (ADP)?

    <p>Removal of one phosphate group from ATP</p> Signup and view all the answers

    Which of the following statements about nucleotides is incorrect?

    <p>Nucleotides do not contain sugars.</p> Signup and view all the answers

    In what form does ATP serve as an energy source for cellular activity?

    <p>In its triphosphate form</p> Signup and view all the answers

    What distinguishes purines from pyrimidines?

    <p>Purines have a fused ring structure.</p> Signup and view all the answers

    Which component of nucleotides binds directly to a phosphate group?

    <p>Ribose sugar</p> Signup and view all the answers

    Which of the following is not a way to increase the number of phosphate groups in nucleosides?

    <p>Hydrolysis of ATP</p> Signup and view all the answers

    Which base is found only in RNA?

    <p>Uracil</p> Signup and view all the answers

    What is the sugar present in RNA?

    <p>Ribose</p> Signup and view all the answers

    Which statement about RNA is incorrect?

    <p>RNA is only found in the nucleus.</p> Signup and view all the answers

    What does the process of semi-conservative replication involve?

    <p>Using one parent strand and creating one new strand.</p> Signup and view all the answers

    How many types of RNA are detailed in the content?

    <p>Three</p> Signup and view all the answers

    What provides the energy for the synthesis of RNA?

    <p>Hydrolysis of phosphate groups</p> Signup and view all the answers

    Which of the following is NOT a nitrogenous base found in RNA?

    <p>Thymine</p> Signup and view all the answers

    Which feature differentiates RNA from DNA?

    <p>RNA has a ribose sugar.</p> Signup and view all the answers

    What is the non-template strand of DNA referred to as?

    <p>Informational strand</p> Signup and view all the answers

    Which enzyme is responsible for unwinding the DNA during transcription?

    <p>RNA polymerase</p> Signup and view all the answers

    In RNA synthesis, which nucleotide replaces thymine in base pairing?

    <p>Uracil</p> Signup and view all the answers

    How many base pairs of the DNA template strand are typically exposed at one time during transcription?

    <p>10</p> Signup and view all the answers

    What is the role of ribonucleotides in the transcription process?

    <p>They replace deoxyribonucleotides during RNA synthesis</p> Signup and view all the answers

    What happens to the newly formed mRNA after transcription?

    <p>It moves to ribosomes in the cytoplasm</p> Signup and view all the answers

    What is a codon in the context of mRNA?

    <p>A sequence of three nucleotides that instructs the start or stop of translation</p> Signup and view all the answers

    What is the result of the transcription process?

    <p>Synthesis of hnRNA</p> Signup and view all the answers

    What is the role of RNA polymerase in the transcription process?

    <p>It links ribonucleotides to form hnRNA.</p> Signup and view all the answers

    During transcription, which strand of DNA is used as the template for hnRNA synthesis?

    <p>The template strand is used.</p> Signup and view all the answers

    In which direction does RNA polymerase synthesize the hnRNA molecule?

    <p>5′ to 3′ direction</p> Signup and view all the answers

    What initiates the end of transcription?

    <p>RNA polymerase encounters a stop signal</p> Signup and view all the answers

    Which of the following describes the 'template strand' during transcription?

    <p>It is the strand that is copied to synthesize hnRNA.</p> Signup and view all the answers

    What happens to the DNA double helix after transcription is completed?

    <p>It rewinds to form the original structure.</p> Signup and view all the answers

    What is the purpose of synthesizing hnRNA during transcription?

    <p>To carry coded information for protein synthesis.</p> Signup and view all the answers

    Which of the following statements about the transcription process is TRUE?

    <p>The transcription process involves unwinding of the DNA double helix.</p> Signup and view all the answers

    Study Notes

    Nucleic Acids Overview

    • Nucleic acids are vital biomolecules that include DNA and RNA, playing crucial roles in genetic information storage and transmission.
    • Nomenclature of nucleotides is determined by the number of phosphate groups present.

    Bases and Their Structures

    • Two categories of bases: Purines (Adenine, Guanine) and Pyrimidines (Cytosine, Thymine, Uracil).
    • Pyrimidines feature a six-membered aromatic ring with two nitrogen atoms; Thymine includes a methyl and carboxyl group, while Uracil is exclusive to RNA.
    • Purines have a fused ring structure containing four nitrogen atoms; Adenine has an amine group while Guanine has an amine, nitrogen, and a carboxyl group.

    Nucleotides and Nucleosides

    • A nucleotide comprises a nitrogenous base, a pentose sugar, and a phosphate group. Without the phosphate, it becomes a nucleoside.
    • In DNA, base pair combinations consist of Adenine-Thymine (A-T) and Guanine-Cytosine (G-C), with hydrogen bonding securing their pairing.
    • ATP (Adenosine Triphosphate) is the primary energy source for cellular activities.

    DNA Structure and Properties

    • DNA exists as a double helix, with two strands of nucleotides running antiparallel to each other.
    • Each base pair maintains equal width due to the pairing of purines and pyrimidines, allowing uniform distance between the two strands.
    • Watson and Crick developed the double helix model of DNA in 1953, with the formation of 10 base pairs per helical turn.

    RNA Characteristics

    • RNA plays the key role of messenger, transmitting genetic instructions from DNA throughout the cell.
    • Distinguishing features of RNA: ribose sugar instead of deoxyribose, single-stranded structure versus DNA’s double-stranded formation, and the presence of Uracil instead of Thymine.
    • RNA synthesizes through a process known as semi-conservative replication where new nucleic acid strands incorporate one parental and one newly synthesized strand.

    Transcription Process

    • Transcription converts DNA into hnRNA/mRNA for protein synthesis.
    • Governed by RNA polymerase, the process involves unwinding DNA and copying a single strand to synthesize mRNA.
    • Transcription steps:
      • DNA section unwinds, exposing a gene.
      • RNA polymerase synthesizes hnRNA by pairing nucleotides, replacing Thymine with Uracil.
      • The mRNA strand exits the nucleus to ribosomes for protein translation.

    Genetic Code and Codons

    • Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids or signal the start and end of protein synthesis.
    • The genetic code is translated by ribosomes where mRNA is synthesized according to template DNA.

    Types of RNA

    • Three main types of RNA:
      • Ribosomal RNA (rRNA)
      • Messenger RNA (mRNA)
      • Transfer RNA (tRNA) which includes anticodons for amino acid pairing during translation.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz explores the essential concepts of nucleic acids in biochemistry, focusing on the number of phosphate groups and their impact on nomenclature. Topics include the structure of purines and pyrimidines, essential for understanding biochemical processes. Ideal for nursing students looking to enhance their foundational knowledge in biochemistry.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser