Core - Cell Biology

    Chapter 9

    Transcription: DNA to RNA

    9.1 : What is Gene Expression?01:36

    9.1 : What is Gene Expression?

    A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised  of nucleotides and proteins are ...

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    9.2 : RNA Structure01:19

    9.2 : RNA Structure

    The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form ...

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    9.3 : Types of RNA01:20

    9.3 : Types of RNA

    Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse ...

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    9.4 : Transcription01:17

    9.4 : Transcription

    Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. ...

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    9.5 : Bacterial RNA Polymerase00:43

    9.5 : Bacterial RNA Polymerase

    Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. ...

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    9.6 : Eukaryotic RNA Polymerases00:58

    9.6 : Eukaryotic RNA Polymerases

    RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional ...

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    9.7 : General Transcription Factors01:30

    9.7 : General Transcription Factors

    Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of ...

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    9.8 : RNA Polymerase II Accessory Proteins02:36

    9.8 : RNA Polymerase II Accessory Proteins

    Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, ...

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    9.9 : Transcription Elongation Factors02:35

    9.9 : Transcription Elongation Factors

    Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not ...

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    9.10 : Pre-mRNA Processing: Modification of pre-mRNA Ends01:35

    9.10 : Pre-mRNA Processing: Modification of pre-mRNA Ends

    In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or ...

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    9.11 : Pre-mRNA Processing: RNA Splicing01:36

    9.11 : Pre-mRNA Processing: RNA Splicing

    Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called ...

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    9.12 : Chromatin Structure and RNA Splicing02:41

    9.12 : Chromatin Structure and RNA Splicing

    In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into ...

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    9.13 : Alternative RNA Splicing02:18

    9.13 : Alternative RNA Splicing

    Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive ...

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    9.14 : Nuclear Export of mRNA02:31

    9.14 : Nuclear Export of mRNA

    Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several ...

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    9.15 : Transfer RNA Synthesis02:35

    9.15 : Transfer RNA Synthesis

    One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the ...

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    9.16 : Ribosomal RNA Synthesis02:53

    9.16 : Ribosomal RNA Synthesis

    Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal ...

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    9.17 : The Nucleolus02:55

    9.17 : The Nucleolus

    The nucleolus is the most prominent substructure of the nucleus. When it was first discovered, it was considered to be an isolated organelle that forms ...

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    9.18 : Additional Subnuclear Structures02:10

    9.18 : Additional Subnuclear Structures

    The eukaryotic nucleus is a double membrane-bound organelle that contains nearly all of the cell’s genetic material in the form of chromosomes. It ...

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