Transcription and Translation Processes in Cells

Genome

Total genetic information of an organism.

Gene Expression

Process where a gene produces a product.

Transcription

Synthesis of RNA from DNA template.

Translation

Synthesis of polypeptide from mRNA.

Folding

Formation of a 3D functional protein structure.

Genotype

Genetic constitution of an organism.

Phenotype

Observable traits resulting from gene expression.

Amino Acids

Building blocks of proteins.

Polypeptide

Chain of amino acids forming proteins.

RNA

Single-stranded nucleic acid for protein synthesis.

mRNA

Messenger RNA carrying genetic information.

RNA Polymerase

Enzyme catalyzing RNA synthesis from DNA.

Promoter Sequence

Region marking the start of a gene.

Transcription Factors

Proteins that initiate transcription by binding to DNA.

Non-coding Sequences

DNA regions that do not code for proteins.

Variable Number Tandem Repeats

Repeated DNA sequences used in DNA profiling.

Silencer Sequences

DNA elements that inhibit gene expression.

Enhancer Sequences

DNA elements that promote gene expression.

Centromere

Regions where sister chromatids attach.

Initiation

First stage of transcription; RNA polymerase binds.

Elongation

RNA polymerase extends RNA transcript.

Termination

Final stage of transcription; RNA transcript released.

RNA Splicing

Modification of RNA before it leaves the nucleus.

Ribosomes

Cellular structures where translation occurs.

RNA polymerase II

Enzyme that synthesizes RNA from DNA template.

Eukaryotic promoters

DNA sequences that initiate transcription.

TATA box

Common promoter sequence in eukaryotes.

Pre-mRNA

Initial RNA transcript before processing.

Template strand

DNA strand used for RNA synthesis.

Non-template strand

DNA strand with same sequence as RNA.

Transcription initiation complex

Assembly of RNA polymerase and transcription factors.

Antisense strand

Template strand for RNA synthesis, complementary to RNA.

Sense strand

Non-template strand with same sequence as RNA.

Base-pairing rules

Guidelines for pairing nucleotides in RNA synthesis.

Transcription unit

Segment of DNA transcribed into RNA.

RNA nucleotides

Building blocks of RNA, including A, U, C, G.

Direction of transcription

RNA synthesis occurs from 5' to 3' end.

Complementary base pairing

A-U and C-G pairing in RNA synthesis.

Tri-phosphates

Energy source added during RNA synthesis.

Ribosome

Cellular machinery that translates mRNA into proteins.

Transcription terminator

DNA sequence signaling the end of transcription.

Unwinding

Separation of DNA strands for RNA pairing.

Hydrogen bonds

Weak interactions between RNA and DNA bases.

Nucleoside triphosphates

Energy sources for RNA synthesis reactions.

Phosphate hydrolysis

Releases energy for RNA nucleotide addition.

3' end addition

Nucleotides are added to RNA's 3' end.

5' to 3' direction

Direction of RNA synthesis during transcription.

Terminator sequence

Signals the end of transcription in DNA.

RNA separation

Complete detachment of RNA from DNA strand.

Introns

Non-coding sequences excised from RNA transcripts.

Exons

Coding sequences that remain in mature mRNA.

Spliceosome

Complex that facilitates RNA splicing.

snRNPs

Small nuclear RNA-protein complexes involved in splicing.

Alternative splicing

Process allowing multiple proteins from one gene.

5' guanine cap

Protective modification added to RNA's 5' end.

Poly A tail

String of adenines added to RNA's 3' end.

Nuclear envelope

Barrier separating transcription and translation in eukaryotes.

Mature mRNA

Processed RNA ready for translation into protein.

5' GTP cap

Modified guanine nucleotide added to mRNA's 5' end.

3' poly-A tail

Chain of adenine nucleotides added to mRNA's 3' end.

RNA processing

Modifications made to pre-mRNA before translation.

splicing

Removal of introns from pre-mRNA to form mRNA.

domains

Distinct functional regions within a protein.

polyadenylation signal

Sequence indicating addition of poly-A tail.

stop codon

Signal for termination of protein synthesis.

start codon

Initiates translation process in mRNA.

3' UTR

Untranslated region following the stop codon.

5' UTR

Untranslated region before the start codon.

adenine nucleotides

Nucleotides added to the 3' end of mRNA.

guanine triphosphate

Nucleotide added to the 5' end of mRNA.

eukaryotic genomes

Genomes with introns and complex regulatory sequences.

non-protein-coding DNA

DNA sequences that do not code for proteins.

tRNA

Transfers amino acids to ribosomes during translation.

Codon

Three-base sequence coding for amino acids.

STOP Codons

Signals termination of protein synthesis.

Anticodon

tRNA sequence matching mRNA codon.

64 Codons

Total possible codons from four bases.

Universal Genetic Code

Same codons specify amino acids across organisms.

RNA Types

Includes mRNA, rRNA, and tRNA.

3' Terminal Site

Location for amino acid attachment on tRNA.

Enzymes in tRNA

Pair tRNA with corresponding amino acids.

Nucleus to Cytoplasm

Pathway for mRNA after transcription.

Nonoverlapping Codons

Codons do not share bases in translation.

Polypeptide Synthesis

Occurs on ribosomes using mRNA template.

Amino-acyl tRNA Synthetase

Enzyme that attaches tRNA to amino acids.

ATP

Energy molecule used in tRNA activation.

rRNA

Ribosomal RNA, component of ribosomal subunits.

P site

Ribosomal site holding tRNA attached to polypeptide.

A site

Ribosomal site for incoming aminoacyl tRNA.

E site

Ribosomal site where discharged tRNA exits.

GTP

Energy source for translation processes.

Peptide Bond

Covalent bond linking amino acids in polypeptide.

Translocation

Movement of tRNA and mRNA during elongation.

Initiator tRNA

tRNA carrying methionine, starts translation process.

Translation Initiation Complex

Assembly of ribosomal subunits and mRNA for translation.

Polypeptide Chain

Sequence of amino acids linked by peptide bonds.

RNA transcript

Initial RNA product before splicing, known as pre-mRNA.

Exon

Coding regions of RNA that remain in mRNA.

Intron

Non-coding regions of RNA removed during processing.

Aminoacyl-tRNA synthetase

Enzyme that attaches amino acids to tRNA.