Biology: From Gene to Protein Part 1

A comprehensive set of vocabulary flashcards focused on key concepts related to transcription, translation, and the genetic code in molecular biology.

Beadle and Tatum

Scientists known for the one gene-one enzyme hypothesis based on mutant mold experiments.

DNA

A double-stranded nucleic acid composed of deoxyribonucleotides, encoding genetic information.

RNA

A single-stranded nucleic acid composed of ribonucleotides, involved in various roles including coding for proteins.

Replication

The process of copying DNA to produce two identical DNA molecules.

Transcription

The synthesis of RNA from a DNA template.

Translation

The process in which ribosomes synthesize proteins using mRNA.

mRNA

Messenger RNA; the form of RNA that carries genetic information from DNA to ribosomes.

Comparing DNA and RNA

DNA is double-stranded, contains deoxyribose, and uses thymine; RNA is single-stranded, contains ribose, and uses uracil.

Transcription in Prokaryotes

Transcription occurs in the cytoplasm and RNA is produced directly as mRNA.

Transcription in Eukaryotes

Transcription occurs in the nucleus, producing pre-mRNA that undergoes processing to become mRNA.

mRNA codon

A sequence of three nucleotides that specifies a single amino acid.

Gene expression

The process by which the information in a gene is used to synthesize a protein.

Introns

Non-coding sequences found within a gene that are removed during RNA processing.

Exons

Coding sequences in a gene that are retained in the final mRNA.

Spliceosomes

Complexes that remove introns from pre-mRNA and join exons together.

Frameshift mutation

A mutation caused by insertions or deletions that shift the reading frame of codons.

Missense mutation

A mutation that results in a different amino acid being incorporated into a protein.

Nonsense mutation

A mutation that introduces a premature stop codon, leading to truncated proteins.

The Central Dogma

The framework describing the flow of genetic information: DNA → RNA → Protein.

RNA processing

Modifications made to pre-mRNA, including capping and polyadenylation, before it becomes mRNA.

Polypeptide

A chain of amino acids that forms a protein.

Transcription factors

Proteins that help initiate and regulate the transcription of genes.

Ribosome

A cellular structure that facilitates the translation of mRNA into protein.

Codon recognition

The process where a tRNA anticodon pairs with a complementary mRNA codon during translation.

tRNA

Transfer RNA; carries specific amino acids to the ribosome during protein synthesis.

Anticodon

A sequence of three nucleotides in tRNA that pairs with a corresponding codon in mRNA.

A site (ribosome)

The site in the ribosome where incoming tRNA brings an amino acid.

P site (ribosome)

The site in the ribosome where the growing polypeptide chain is held.

E site (ribosome)

The exit site in the ribosome where tRNAs leave after contributing their amino acids.

RNA polymerase

The enzyme that synthesizes RNA from a DNA template during transcription.

Elongation (transcription)

The phase of transcription where RNA polymerase synthesizes the RNA strand.

Termination (transcription)

The end of transcription where RNA polymerase detaches from the DNA after synthesizing mRNA.

5' cap

A modified guanine nucleotide added to the 5' end of mRNA that aids in export and stability.

Poly-A tail

A sequence of adenine nucleotides added to the 3' end of mRNA that protects it from degradation.

Alternative RNA splicing

The process allowing a single gene to produce multiple mRNA forms by including different combinations of exons.

Polyribosomes

Clusters of ribosomes translating the same mRNA strand simultaneously.

Chaperonin

A protein that assists in the correct folding of newly synthesized polypeptides.

Signal peptide

A short amino acid sequence at the beginning of a polypeptide that directs it to its appropriate location.

Point mutations

Small-scale mutations that affect a single nucleotide pair in a gene.

Base-pair substitution

A point mutation where one base pair is replaced by another.

Aminoacyl-tRNA synthetase

An enzyme that attaches the correct amino acid to its corresponding tRNA.

Ribozyme

An RNA molecule that can act as an enzyme to catalyze biochemical reactions.

Nondisjunction

An error in meiosis or mitosis where chromosomes do not properly segregate.

Translocation

A chromosomal mutation where a segment of DNA is transferred from one location to another.

Duplication (mutation)

A mutation that results in the doubling of a segment of DNA.

Deletion (mutation)

A mutation that involves the loss of a segment of DNA.

Sickle Cell Disease

A genetic disorder caused by a point mutation in hemoglobin leading to distorted red blood cells.

Valine (Val)

The amino acid produced due to the mutated mRNA in sickle cell disease.

Glu (Glutamic acid)

The normal amino acid that is replaced by Valine in sickle cell hemoglobin.

Heat-shock proteins

Proteins that help refold denatured proteins during stress.

Transcription unit

A segment of DNA that is transcribed into RNA.

RNA nucleotides

The building blocks of RNA, consisting of a sugar, phosphate, and a nitrogenous base.

TATA box

A conserved sequence in promoter regions that helps in the initiation of transcription.

Ribosomal subunit

The two distinct structures that compose a ribosome, responsible for translating mRNA.

Wobble effect

The relaxed base-pairing rules that allow tRNA to recognize multiple codons.

Termination codon

A codon in mRNA that signals the end of translation.

Signal-recognition particle (SRP)

A complex that helps direct ribosomes to the endoplasmic reticulum.

Mutations

Changes in the nucleotide sequence of DNA that may affect protein structure.

Amino acid sequence

The linear sequence of amino acids in a polypeptide, determined by mRNA codons.

200 amino acids

The number of amino acids coded by 600 nucleotides in mRNA.

Polypeptide synthesis

The process of creating a chain of amino acids based on the sequence of codons in mRNA.

Biological information flow

The transfer of genetic information from DNA to RNA to proteins.

Catalytic roles of RNA

Functions performed by RNA molecules that include facilitating chemical reactions.

Mutant mold experiments

Experiments by Beadle and Tatum demonstrating the link between genes and enzymes.

Protein synthesis location

Translation occurs at ribosomes in the cytoplasm.

Codon

A sequence of three nucleotides in mRNA that specifies an amino acid.

Stop codons

Nucleotide triplets that terminate translation: UAG, UAA, UGA.

Expression of genes

The manifestation of a gene's information through the production of RNA or proteins.

mRNA length for protein synthesis

An mRNA molecule with 600 nucleotides can code for a protein with 200 amino acids.

Ribosomal RNA (rRNA)

The RNA component of ribosomes that plays a structural and catalytic role.

Signal peptides role

Direct newly synthesized proteins to their cellular destination.

Free ribosomes

Ribosomes that synthesize proteins that function in the cytosol.

Bound ribosomes

Ribosomes attached to the endoplasmic reticulum that produce proteins for secretion.

Role of introns

To allow alternative splicing and gene regulation.

Effects of mutations

Change in genetic sequences can lead to changes in protein function and structure.

Nuclear envelope

The double membrane surrounding the nucleus in eukaryotic cells.

5' to 3' direction

The direction in which RNA synthesizes during transcription.

RNAi

Interference RNA; involved in gene regulation by suppressing gene expression.

Chaperonin function

Provides an environment for the correct folding of polypeptides.

Polypeptide chain folding

The process of a polypeptide chain folding into its functional 3D structure.

Role of translation

To synthesize proteins based on the instructions carried by mRNA.

RNA processing steps

Includes capping, polyadenylation, and splicing of pre-mRNA.

Gene modification by transcription factors

Transcription factors help transcription by affecting RNA polymerase binding.

Nonsense mutations effect

Lead to premature termination of protein synthesis.

Silent mutations definition

Mutations that do not change the amino acid sequence of a protein.