Molecular Biology: Genetics, Transcription, Translation, and Gene Regulation

Vocabulary practice flashcards covering nucleic acid structure, protein synthesis (transcription and translation), RNA processing, and mechanisms of gene regulation.

Genome (Genom)

The hereditary information encoded within an organism's DNA.

Sugar-Phosphate Backbone

The repeating structural strand pattern of sugar and phosphate units in the DNA double helix, joined together by covalent bonds.

Phosphate Group (in DNA)

A negatively charged chemical group that gives the DNA molecule its overall negative electrical charge.

Adenine-Thymine Base Pairing

A complementary base pair in DNA connected by a double hydrogen bond.

Cytosine-Guanine Base Pairing

A complementary base pair in DNA connected by a triple hydrogen bond.

Chromosomes (Kromosomer)

Structures located in the cell nucleus consisting of a linear DNA molecule coiled around a protein skeleton.

Histones (Histoner)

Proteins that make up the structural skeleton around which DNA coils and packs tightly to form a chromosome.

Protein Synthesis (Proteinsyntese)

The cellular process of building proteins according to the instructions encoded in DNA.

Codon (Kodon)

A triplet of three consecutive nucleotide bases in nucleic acids that specifies which amino acid to assemble into a protein.

Gene (Gen)

A specific coding sequence in DNA containing instructions for synthesizing proteins.

Essential Amino Acids

A group of $9$ amino acids that the human body cannot produce on its own and must modify from existing amino acids to acquire new properties.

Transcription (Transkripsjon)

The process of copying the genetic code of a gene from DNA to produce an mRNA transcript.

Transcription Factors

A group of proteins that act as a start signal by binding to the promoter to enable RNA polymerase attachment.

RNA Polymerase

The enzyme complex that attaches to the promoter after transcription factors bind, synthesizing an mRNA strand through covalent bonds between RNA nucleotides.

mRNA Strand Direction

The direction in which mRNA is synthesized, running $5' \rightarrow 3'$, complementary to the DNA template strand running $3' \rightarrow 5'$.

Coding Strand (Kodende tråd)

The non-transcribed DNA strand that runs in the $5' \rightarrow 3'$ direction and contains the genetic code.

Exons (Eksoner)

Coding regions of a gene that contain the recipes for synthesizing proteins.

Introns (Introner)

Non-coding sequences of a gene located between two exons that do not contain protein recipes.

5' Cap (5cap)

A cap of phosphate groups added to the $5'$ end of pre-mRNA to prevent degradation, facilitate transport out of the nucleus, and ensure correct ribosome attachment.

3' Poly-A Tail (3poly-A)

A tail of adenine nucleotides attached to the $3'$ end of pre-mRNA to protect the transcript from degradation in the cytosol.

RNA Splicing (RNA-spleising)

The post-transcriptional process of removing introns from pre-mRNA so that only exons remain.

Spliceosome (Spliceosom)

An enzyme complex that cleaves mRNA, removes introns, and splices exons together.

Translation (Translasjon)

The process occurring at ribosomes where the mRNA base sequence is decoded into a sequence of amino acids to produce proteins.

Ribosome

A cellular structure composed of rRNA and proteins where amino acids are linked together using energy.

tRNA (Transfer RNA)

Molecules composed of RNA nucleotides found free in the cytosol that carry specific amino acids to the ribosome.

Anticodon (Antikodon)

A specific sequence of RNA nucleotides on a tRNA molecule that pairs complementarily with a codon on mRNA.

tRNA Synthetase

The enzyme that recognizes the anticodon on a tRNA molecule and links it to the corresponding correct amino acid.

AUG

The specific nucleotide base triplet on an mRNA strand that acts as the start signal for translation.

Stop Codons (Sluttsignaler)

The three mRNA base triplets—UAA, UAG, and UGA—that serve as stop signals to terminate translation.

Primary Structure (Primærstruktur)

The foundational level of protein structure defined by the linear sequence of amino acids in a polypeptide chain.

Secondary Structure (Sekundærstruktur)

The structural level of a protein formed when specific regions of the polypeptide chain fold.

Gene Regulation (Genregulering)

Mechanisms allowing the body to selectively choose which genes are read and which mRNAs and proteins are synthesized, influenced by diet, environment, and physical activity.

CpG Site (CPG-gruppe)

A DNA region where cytosine is bound to guanine; cytosine often carries a methyl group that acts as a signal regarding DNA packaging.

Promoter (Promotor)

A regulatory DNA sequence positioned upstream of a gene where transcription factors and RNA polymerase bind to initiate transcription.

Lac Z

The gene encoding the enzyme galactosidase, which is responsible for breaking down lactose in the cell.

Alternative Splicing (Alternativ-spleising)

A form of post-transcriptional regulation where pre-mRNA is cut and spliced in different ways to produce multiple distinct protein variants from a single gene.