Blue words

CstF (Cleavage Stimulation Factor)

A protein complex that enhances cleavage and polyadenylation of mRNA precursors, interacting with CPSF.

PolyA Polymerase (PAP)

The enzyme that adds a poly-A tail to the 3' end of mRNA after cleavage, essential for mRNA stability.

PolyA Binding Protein (PABII)

A protein that binds to the poly-A tail of mRNA, protecting it from degradation and aiding in translation initiation.

DNA Melting

The process of separating the two strands of DNA by breaking hydrogen bonds, essential for replication and transcription.

Melting Temperature

The temperature at which half of the DNA strands are denatured, indicative of DNA stability.

Hybridization

The formation of a double-stranded nucleic acid molecule through complementary base pairing between sequences from different sources.

Exons

Coding regions of a gene that are expressed in mature mRNA and translated into proteins.

Introns

Non-coding regions of a gene that are removed during mRNA processing.

Spliceosome

A complex of proteins and RNA responsible for catalyzing the removal of introns and joining of exons in pre-mRNA.

Alternative Splicing

A process that enables a single gene to produce multiple mRNA transcripts by including or excluding different exons.

cDNA (complementary DNA)

DNA synthesized from mRNA using reverse transcriptase, containing only the coding regions.

Reverse Transcriptase

An enzyme that synthesizes DNA from an RNA template, often used in cDNA synthesis.

Peptide Bond

A covalent bond linking two amino acids in a protein, formed during protein synthesis.

N-terminus

The start of a polypeptide chain where the amino group is located.

C-terminus

The end of a polypeptide chain where the carboxyl group is located.

Codon

A triplet sequence of nucleotides in mRNA that codes for a specific amino acid.

RNA Polymerase III

An enzyme responsible for transcribing tRNA and other small RNA genes.

Ribosome Binding Site (RBS)

The region on mRNA where the ribosome binds to initiate translation.

Polycistronic mRNA

mRNA that carries multiple coding sequences, enabling the production of multiple proteins.

Initiation Codon

The codon (usually AUG) that signals the start of translation.

Stop Codons

Codons (UAA, UAG, UGA) that signal the termination of translation.

Ribozymes

Catalytic RNA molecules that can act like enzymes in biochemical reactions.

Alternative 3’ Cleavage Site Choice

Selection of different sites for cleavage and polyadenylation from mRNA precursors, resulting in isoforms.

5’ Splice Site

The sequence at the start of an intron where splicing occurs during mRNA processing.

3’ Splice Site

The sequence at the end of an intron where splicing occurs during mRNA processing.

Branch Point

A specific nucleotide within an intron where the spliceosome complex binds during splicing.

Decoding Center

The part of the ribosome where mRNA codon-anticodon pairing occurs during translation.

Kozak Consensus Sequence

Nucleotide sequence surrounding the initiation codon that enhances the translation efficiency in eukaryotic mRNA.

Chaperone

Proteins that assist the folding of other proteins.

Post-Translational Modification

Chemical modifications that occur to proteins after synthesis, altering their function.

Aminoacyl-tRNA Synthetases

Enzymes attaching specific amino acids to their corresponding tRNA molecules.

Consensus Sequences

Short, conserved sequences in DNA recognized by proteins for transcription and regulation.

Euchromatin

Less condensed chromatin, associated with active transcription of genes.

Heterochromatin

Highly condensed chromatin, typically associated with inactive genes.

Histone Code

Specific patterns of histone modifications that regulate gene expression.

DNA Ligase

An enzyme that joins Okazaki fragments and seals nicks in the DNA backbone during replication.

Transformation

The process of introducing foreign DNA into a host cell.

Electrophoresis

A technique for separating nucleic acids or proteins based on size and charge.

Polymerase Chain Reaction (PCR)

A method used to amplify specific DNA sequences in vitro.

Recombinant DNA Technology

The manipulation of DNA sequences from different sources to generate recombinant molecules.

Operon

A genetic regulatory system in prokaryotes with multiple genes under the control of a single promoter.

Activators

Proteins that enhance transcription by binding to specific DNA sequences.

Repressors

Proteins that inhibit gene expression by blocking transcription.

CPSF (cleavage and polyadenylation specificity factor)

CPSF is a protein complex involved in the cleavage and polyadenylation of mRNA precursors. It recognizes and binds to the polyadenylation signal on the mRNA and recruits other factors for mRNA processing.

CstF (cleavage stimulation factor)

CstF is a protein complex that interacts with CPSF to promote the cleavage and polyadenylation of mRNA precursors. It helps stimulate the cleavage process at the correct site.

Cleavage factors (CFI, CFII)

CFI and CFII are additional protein complexes involved in the cleavage of mRNA precursors. They work together with CPSF and CstF to ensure accurate and efficient cleavage.

PolyA polymerase (PAP)

PolyA polymerase is the enzyme responsible for adding a poly-A tail to the 3' end of mRNA after cleavage. This poly-A tail is important for mRNA stability and translation.

PolyA binding protein (PABII)

PABII is a protein that binds to the poly-A tail of mRNA. It helps protect the mRNA from degradation and is involved in the initiation of translation.

DNA melting or denaturation

DNA melting or denaturation is the process of separating the two strands of DNA by breaking the hydrogen bonds between base pairs. This is important for processes like DNA replication and transcription.

Melting temperature

The melting temperature is the temperature at which half of the DNA strands are denatured. It is a measure of DNA stability and is influenced by factors like GC content.

Renaturation or reannealing

Renaturation or reannealing is the process of two single-stranded DNA molecules coming back together to form a double helix. This process can occur when conditions favor base pairing.

Hybridization

Hybridization is the process of forming a double-stranded nucleic acid molecule by bringing together complementary sequences from two different sources. It is used in techniques like PCR, DNA microarrays, and Southern blotting.

Hybrid molecule

A hybrid molecule is a molecule formed by combining two different types of molecules, such as DNA-RNA hybrids or protein-DNA hybrids.

Exons

Exons are the coding regions of a gene that are expressed in the mature mRNA and are translated into protein. They are interspersed with introns in eukaryotic genes.

Introns

Introns are non-coding regions of a gene that are removed during mRNA processing. They are present in the initial transcript but are spliced out before translation.

5’ splice site

The 5' splice site is the sequence at the beginning of an intron where splicing occurs during mRNA processing. It is recognized by the spliceosome for intron removal.

3’ splice site

The 3' splice site is the sequence at the end of an intron where splicing occurs during mRNA processing. It is also recognized by the spliceosome for intron removal.

Branch point

The branch point is a specific nucleotide sequence within an intron where the spliceosome complex binds during mRNA splicing. It is where the lariat structure is formed during splicing.

Spliceosome

The spliceosome is a complex of proteins and RNA molecules that catalyze the removal of introns and joining of exons during mRNA processing. It is crucial for the precise splicing of pre-mRNA.

Alternative splicing

Alternative splicing is a process that allows a single gene to produce multiple mRNA transcripts by selectively including or excluding different exons. This increases the diversity of proteins encoded by the genome.

Alternative 3’ cleavage site choice

This refers to the alternative selection of different sites for cleavage and polyadenylation during mRNA processing. It can lead to the production of mRNA isoforms with different 3' ends.

cDNAs

cDNAs are complementary DNA molecules synthesized from mRNA using reverse transcriptase. They lack introns and represent the coding regions of genes.

Reverse transcriptase (RT)

Reverse transcriptase is an enzyme that catalyzes the synthesis of DNA from an RNA template. It is used in processes like reverse transcription PCR and cDNA synthesis.

cDNA library

A cDNA library is a collection of cDNA fragments representing the genes expressed in a particular cell type. It is used for gene expression studies and cloning of genes.

Amino acids; alpha carbon

The alpha carbon is a central carbon atom found in all amino acids to which an amino group, a carboxyl group, a hydrogen atom, and a side chain are attached. It is essential for the structure and function of amino acids.

Amino acids; L conformation

L conformation refers to the left-handed configuration of amino acids in the standard form found in proteins. Amino acids in living organisms predominantly exist in the L conformation.

Post-translational modification

Post-translational modifications are chemical modifications that occur on proteins after they have been synthesized. These modifications can alter protein function, localization, and stability.

Polypeptide chains

Polypeptide chains are chains of amino acids linked by peptide bonds that make up proteins. Polypeptide chains can fold into specific three-dimensional structures to perform their biological functions.

Peptide bond

A peptide bond is a covalent bond that links two amino acids together in a protein. It forms between the carboxyl group of one amino acid and the amino group of another during protein synthesis.

The N terminus

The N-terminus is the end of a polypeptide chain where the amino group is located. It is the starting point for protein synthesis and determines the directionality of the protein chain.

The C terminus

The C-terminus is the end of a polypeptide chain where the carboxyl group is located. It is the ending point for protein synthesis and can play a role in protein folding and function.

Co-linear

Co-linear refers to the arrangement of DNA or RNA sequences where the order of nucleotides corresponds to the order of amino acids in a protein. This means that the genetic code is read in a linear and sequential manner.

Non-overlapping

Non-overlapping refers to the genetic code where each nucleotide is only part of a single codon and does not overlap with adjacent codons. This ensures that the genetic code is read accurately during protein synthesis.

RNA pol III

RNA polymerase III is an enzyme that transcribes tRNA and other small RNA genes. It is responsible for synthesizing various small functional RNAs in the cell.

Clover structure

The clover structure is a common secondary structure found in tRNA molecules. It consists of three hairpin loops and a stem-loop structure, resembling a cloverleaf shape.

Isoaccepting tRNAs

Isoaccepting tRNAs are different tRNA molecules that accept the same amino acid but have different anticodon sequences. They help in translating the genetic code accurately by recognizing different codons.

Aminoacyl-tRNA synthetases

Aminoacyl-tRNA synthetases are enzymes responsible for attaching amino acids to tRNA molecules during protein synthesis. They ensure that the correct amino acid is paired with the corresponding tRNA.

Coding region

The coding region of a gene contains the sequence that will be translated into a protein. It consists of exons that are spliced together to form mature mRNA for protein synthesis.

5’untranslated region (5’ UTR)

The 5' untranslated region is the sequence at the beginning of an mRNA molecule that is not translated into protein. It contains regulatory elements that control mRNA stability and translation efficiency.

3’untranslated region (3’ UTR)

The 3' untranslated region is the sequence at the end of an mRNA molecule that is not translated into protein. It contains signals for mRNA degradation, localization, and regulation of translation.

Initiation

Initiation is the beginning stage of protein synthesis where the ribosome assembles on mRNA to start translation. It involves the recognition of the start codon and recruitment of the ribosome complex.

Elongation

Elongation is the stage of protein synthesis where amino acids are added to the growing polypeptide chain. It involves the decoding of mRNA codons and peptide bond formation.

Termination

Termination is the final stage of protein synthesis where the ribosome releases the completed polypeptide chain and dissociates from the mRNA. It occurs when a stop codon is encountered.

CCA

CCA is a sequence found at the 3' end of tRNA molecules that is important for amino acid attachment. It is where the amino acid binds to the tRNA before being delivered to the ribosome.

Decoding center

The decoding center of the ribosome is where the mRNA codon is matched with the anticodon of the tRNA during translation. It ensures accurate recognition and incorporation of amino acids into the growing polypeptide chain.

Peptidyltransferase center

The peptidyltransferase center of the ribosome is where peptide bond formation occurs during translation. It catalyzes the formation of peptide bonds between amino acids.

Shine-Dalgarno sequence

The Shine-Dalgarno sequence is a ribosomal binding site in prokaryotic mRNA that interacts with the ribosome to initiate translation. It is involved in positioning the ribosome on the mRNA.

Ribosome Binding Site (RBS)

The Ribosome Binding Site is where the ribosome binds to mRNA to initiate translation. It is essential for the proper positioning of the ribosome and initiation of protein synthesis.

30 S initiation complex

The 30S initiation complex is the complex formed by the small ribosomal subunit, mRNA, and initiation factors during translation initiation. It is a key step in the initiation of protein synthesis.

70 S initiation complex

The 70S initiation complex is the complex formed by the association of the small and large ribosomal subunits during translation initiation in prokaryotes. It marks the beginning of the translation process.

Polysomes

Polysomes are multiple ribosomes that are translating the same mRNA molecule simultaneously. They allow for the efficient and continuous synthesis of multiple protein copies from a single mRNA.

Kozak consensus

The Kozak consensus sequence is a nucleotide sequence surrounding the start codon that helps to initiate translation in eukaryotic mRNA. It enhances the recognition of the start codon by the ribosome.

Polycistronic

Polycistronic mRNA contains multiple coding sequences that can be translated into different proteins. It is commonly found in prokaryotic transcripts where multiple genes are clustered together.

Monocistronic

Monocistronic mRNA contains a single coding sequence that is translated into a single protein. It is typical in eukaryotic transcripts where genes are usually expressed individually.

Hairpin (stem/loops)

In nucleic acids, particularly RNA, a hairpin structure is formed when a sequence folds back on itself, creating a stem-loop structure. The stem consists of base-paired nucleotides, while the loop is the unpaired region. Hairpins are important for RNA folding, stability, and regulatory functions.

Stems

Stems in nucleic acids refer to regions where complementary bases pair to form a double-stranded structure. Stems are often part of hairpin loops or other secondary structures in RNA molecules.

Ribozymes

Ribozymes are RNA molecules that possess catalytic activity, similar to enzymes. They can catalyze specific biochemical reactions due to their three-dimensional structure. Ribozymes play essential roles in RNA processing and various cellular processes.

RNA (ribonucleic acid)

RNA is a molecule essential for various biological processes, including gene expression and protein synthesis. It is transcribed from DNA and can be involved in functions such as mRNA translation, tRNA-mediated protein synthesis, and regulatory roles.

Transcription

Transcription is the process of synthesizing RNA from a DNA template. It occurs in the nucleus of eukaryotic cells and is catalyzed by RNA polymerases. Transcription is a key step in gene expression.

RNA polymerases

RNA polymerases are enzymes responsible for synthesizing RNA from a DNA template during transcription. Different types of RNA polymerases (I, II, III) are involved in transcribing specific types of RNA molecules.