13: Biomolecules - Nucleic Acids
- Page ID
- 559985
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)When you have completed Chapter 14, you should be able to
- fulfill all of the detailed objectives listed under each individual section.
- draw the structure of a given nucleotide.
- discuss the structure of DNA and RNA.
- describe the processes involved in DNA replication, transcription, translation, and protein synthesis.
- define, and use in context, the key terms introduced in this chapter.
Two types of nucleic acids are found in cells—deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). These highly complex substances are built up from a number of simpler units, called nucleotides. Each nucleotide consists of three parts: a phosphoric acid residue, a sugar and a nitrogen‑containing heterocyclic base. Thus, in order to understand the biochemistry of the nucleic acids, you must first study the chemistry of the sugars (see Chapter 11) and simple heterocyclic systems. We have already discussed certain aspects of the structure of heterocyclic ring systems during our study of aromaticity (Sections 3.5–3.6). You may find it helpful to review this chapter.
Chapter 14 examines the structure and replication of DNA and then describes the structure and synthesis of RNA. The chapter closes with a brief study of RNA's role in protein biosynthesis.
- 13.0: Why This Chapter?
- This chapter introduces nucleic acids, focusing on their essential roles in genetic information storage and transmission. It discusses the structures and functions of DNA and RNA, highlighting their involvement in heredity, protein synthesis, and cellular activities. The chapter emphasizes the importance of understanding nucleic acids for grasping molecular biology concepts and the mechanisms underlying life processes.
- 13.1: Nucleotides and Nucleic Acids
- The Learning Objective of this Module is to identify the different molecules that combine to form nucleotides.
- 13.3: Transcription of DNA
- Transcription is the process by which DNA is converted into RNA. It begins when RNA polymerase binds to the promoter region of a gene, unwinding the DNA strands. The enzyme synthesizes a complementary RNA strand by adding ribonucleotides, following base-pairing rules. After synthesis, the mRNA undergoes processing, including the addition of a 5' cap and a poly-A tail, before it exits the nucleus to be translated into protein. This mechanism is vital for gene expression and cellular function.
- 13.4: Translation of RNA - Protein Biosynthesis
- Translation is the process of synthesizing proteins from mRNA. It occurs in three main stages: initiation, elongation, and termination. Ribosomes read the mRNA sequence in codons, which correspond to specific amino acids. tRNA molecules, carrying amino acids, bind to the ribosome at the anticodon region, facilitating the assembly of a polypeptide chain. Once a stop codon is reached, the newly formed protein is released. This process is crucial for cellular functions and organismal developement.
- 13.7: Chemistry Matters—DNA Fingerprinting
- DNA fingerprinting, or profiling, is a technique used to identify individuals based on unique patterns in their DNA. This method analyzes variable regions of DNA, particularly short tandem repeats (STRs), which differ significantly among individuals. It's widely utilized in forensic science for crime scene investigations, paternity testing, and identifying genetic relationships. DNA fingerprinting's reliability stems from its ability to distinguish between closely related individuals.
- 13.S: Biomolecules - Nucleic Acids (Summary)
- This summary outlines the key aspects of nucleic acids, including the structure and function of DNA and RNA, the processes of transcription and translation, and the significance of DNA replication. It emphasizes the role of nucleic acids in genetic information storage, expression, and heredity. The chapter also covers techniques like DNA sequencing and polymerase chain reaction (PCR), which have crucial applications in biotechnology and medicine.