BIOL 107 Part G - DNA and RNA (Terms)

Plasmids

Circular DNA found in prokaryotes found everywhere in the cytosol, with ~1000 copies per cell

Nucleosome

The units of nuclear chromosomes, made of nuclear DNA wrapped around Histone proteins within the nucleus to form a complex, linking to create 30 nm fibres

Template Strand

A single strand from a separated DNA helix that is the model used to create a new DNA strand, forming half of a new daughter DNA molecule

RNA Polymerase

An enzyme that is responsible for RNA synthesis with the ability to elongate and initiate, thus able to create a complementary RNA strand from a template DNA strand

DNA Polymerases

A group of enzymes with universal mechanisms that each play a specific role in DNA replication

DNA Polymerase I

The DNA polymerase responsible for the repair of DNA and the removal of primers from the new strand in DNA replication, with the ability to elongate, proofread, repair, and remove primers

DNA Polymerase III

The DNA polymerase responsible for the main elongation of the new strand in DNA replication, with the ability to elongate and proofread

RNA Primers

Small, 10 nt RNA strands that act as a guidepoint to initiate DNA replication and facilitate lagging strand creation

Primase

An RNA polymerase enzyme that creates RNA primers during DNA replication

Origin of Replication (ori)

The point from which DNA replication begins, where replication will fork out in both directions

Leading Strand

The new strand of DNA created continuously from the template strand oriented 3’ to 5’ at the ori

Lagging Strand

The new strand of DNA created section by section in Okazaki fragments from the template strand oriented 5’ to 3’ at the ori

Okazaki Fragments

~1000 nt long DNA fragments that are created as sections of the lagging strand

DNA Ligase

An enzyme that joins already present DNA nucleotides in the lagging strand

Topoisomerase

A protein that untangles DNA in front of the replication fork in preparation for DNA replication

Helicase

A protein that separates the strands of DNA after initiation at the replication fork in preparation for DNA replication by forming a ring around the lagging strand

Single Stranded Binding (SSB) Proteins

Proteins that keep the strands of DNA separated during DNA replication

Initiators

Small proteins that pull strands apart to start replication by connecting to each other and binding to DNA

Telomeres

The ends of linear chromosomes with specific DNA that must be replicated by Telomerase

Telomerase

A DNA polymerase enzyme that replicates telomere DNA at the ends of linear chromosomes

Central Dogma of Biology

A theory stating that genetic information flows only in one direction: from DNA, to RNA, to protein

Ribonucleic Acid (RNA)

A nucleic acid made from NTPs that is the intermediate between DNA in the nucleus and proteins in the cytosol, bringing genetic information into ribosomes for protein synthesis

Gene

A region on a DNA molecule that contains the information responsible for the production of an RNA molecule

Codon

A 3 nucleotide unit of an RNA strand that encodes for one specific amino acid

Methionine (Met)

The amino acid that encodes the start of protein synthesis, with code AUG

Ter (X)

The amino acid that encodes the stop of protein synthesis, with multiple stop codes

Messenger RNA (mRNA)

A long, mature type of temporary RNA created in the process of translation that contains the genetic information read by a ribosome to create a protein

Ribosomal RNA (rRNA)

A type of RNA created in the process of translation that makes up ribosomes along with proteins

Transfer RNA (tRNA)

A type of RNA that carries a single amino acid corresponding to a codon in protein synthesis

Transcription

The synthesis of RNA from a DNA molecule, transferring the permanent genetic information onto a temporary messenger

Promoter DNA

A section of DNA with a recognizable gene sequence at the start of a gene that an RNA polymerase attaches to in order to initiate transcription

General Transcription Factor (TF) Proteins

Proteins that act as a marker to help RNA polymerase find the promoter region during transcription initiation

Terminator DNA

A section of DNA with a recognizable gene sequence at the end of a gene that signals RNA polymerase to release the DNA and fall off to terminate transcription

Intrinsic Termination

The process of terminating transcription used by both prokaryotes and eukaryotes that is done by the created RNA itself

Factor-Dependent Termination

The process of terminating transcription used by both prokaryotes and eukaryotes in which the RNA sequence recruits a protein to aid in the termination process

RNA Processing

The stage between RNA synthesis and maturing of the RNA molecule that gives pre-RNA necessary modifications to specialize into tRNA, rRNA, or mRNA

Cleavage Factor

A protein recruited by the RNA sequence AAUAAA that performs factor-dependent termination and recruits poly(A) polymerase during mRNA processing

Capping Factor

A protein that attaches the 5’ cap to a pre-RNA molecule during mRNA processing

Poly (A) Polymerase

An RNA polymerase that attaches a poly(A) tail to a pre-RNA molecule during mRNA processing

5’ Cap

A backwards G nucleotide attached to the 5’ end of an mRNA molecule during mRNA processing

Poly(A) Tail

A tail sequence consisting of a chain of 150-200 A nucleotides in a row attached to the 3’ end of an mRNA molecule during mRNA processing

Intron

An intervening region of an RNA strand (or the DNA region that encoded it) found only in eukaryotic mRNA that does not express genetic information needed in protein synthesis and thus is removed from mature mRNA

Exon

An expressed region of an RNA strand (or the DNA region that encoded it) that contains genetic information needed in protein synthesis and thus remains in mature mRNA

Splicing Factors

Proteins that mark the location of introns while mRNA synthesis is occurring through locating and situating at exon/intron boundaries and intron/exon boundaries

Spliceosomes

Molecular machines made of RNA and proteins that remove introns and ligate exons during mRNA processing