Mendelian Genetics and the Central Dogma of Biology

DNA

Deoxyribonucleic acid, genetic material in organisms.

RNA

Ribonucleic acid, involved in protein synthesis.

mRNA

Messenger RNA, carries genetic information from DNA.

tRNA

Transfer RNA, brings amino acids to ribosomes.

Central Dogma

Process: DNA → RNA → Protein synthesis.

Nucleotide

Building block of DNA and RNA.

Gene

Segment of DNA coding for a protein.

Chromosome

Structure containing DNA, organized into genes.

Allele

Variant form of a gene at a locus.

Phenotype

Observable traits resulting from genotype expression.

Genotype

Genetic makeup of an organism.

Mutation

Change in DNA sequence affecting genetic information.

Karyotype

Visual representation of an organism's chromosomes.

Homozygous

Having two identical alleles for a trait.

Heterozygous

Having two different alleles for a trait.

Telomere

End region of a chromosome, protects DNA.

Locus

Specific location of a gene on a chromosome.

Codon

Three-nucleotide sequence coding for an amino acid.

Centromere

Region joining two sister chromatids in a chromosome.

Central Dogma

Flow of genetic information: DNA → RNA → Protein.

Reverse Transcription

RNA to DNA conversion by reverse transcriptase.

Reverse Transcriptase

Enzyme in retroviruses for reverse transcription.

Prokaryotic Cells

Cells without a nucleus, transcription and translation simultaneous.

Eukaryotic Cells

Cells with a nucleus, separate transcription and translation.

Transcription

Process of synthesizing RNA from DNA template.

Translation

Process of synthesizing proteins from mRNA.

mRNA Splicing

Removal of introns and joining of exons.

Introns

Non-coding regions removed during mRNA processing.

Exons

Coding regions that exit the nucleus for translation.

DNA Polymerase

Enzyme that synthesizes new DNA strands.

Replication Fork

Y-shaped region where DNA is replicated.

Leading Strand

Continuously synthesized DNA strand during replication.

Lagging Strand

Discontinuously synthesized DNA strand with Okazaki fragments.

Okazaki Fragments

Short DNA segments on the lagging strand.

Telomeres

Repeated DNA sequences at chromosome ends.

Polymerase Chain Reaction (PCR)

Technique to amplify specific DNA sequences.

RNA Processing

Modifications to RNA before translation.

Codons

Three-nucleotide sequences in mRNA coding for amino acids.

Anticodons

tRNA sequences complementary to mRNA codons.

Stop Codons

Codons signaling termination of translation.

Peptide Bonds

Covalent bonds linking amino acids in proteins.

Primary Structure

Unique sequence of amino acids in a protein.

Secondary Structure

Coils and folds formed by hydrogen bonds.

Tertiary Structure

3D shape of a protein from R group interactions.

Quaternary Structure

Complex of multiple polypeptide chains.

Allosteric Proteins

Proteins that change shape to regulate activity.

Point Mutation

Change in a single nucleotide in DNA.

Silent Mutation

Nucleotide change with no effect on amino acid.

Missense Mutation

Nucleotide change resulting in a different amino acid.

Nonsense Mutation

Nucleotide change creating a premature stop codon.

Protein Modifications

Post-translational changes affecting protein function.

Gene Families

Groups of related genes in the genome.

Pseudogenes

Nonfunctional gene duplicates in the genome.

Transposons

DNA sequences that can move within the genome.

Nucleosome

Basic unit of DNA packaging with histones.

Chromatin Remodeling

Process allowing gene expression by uncoiling DNA.

Mendelian Inheritance

Patterns of inheritance based on dominant and recessive alleles.

Autosomal Dominant

Requires one copy of a dominant allele to express phenotype.

Autosomal Recessive

Requires two copies of a recessive allele to express phenotype.

Sex-Linked Inheritance

Inheritance patterns associated with X or Y chromosomes.

Genetic Anticipation

Worsening of a disorder in successive generations.

Founder Effect

Reduced genetic diversity from a small population.

Heterozygote Advantage

Benefit of carrying one copy of a recessive allele.

Dysmorphology

Study of physical features for syndrome identification.

MicroRNAs

Small non-coding RNAs regulating gene expression.

Clinical Correlation

Linking genetic findings to clinical symptoms.

Phenotype

Observable traits resulting from gene expression.

Reverse Transcription

RNA converted back to DNA by reverse transcriptase.

Prokaryotic Cells

Cells without a nucleus; transcription and translation simultaneous.

Eukaryotic Cells

Cells with a nucleus; transcription and translation separate.

Splicing

Removal of introns from mRNA, leaving exons.

mRNA

Messenger RNA; carries genetic information for protein synthesis.

tRNA

Transfer RNA; brings amino acids to ribosomes.

rRNA

Ribosomal RNA; component of ribosomes.

Replication Fork

Y-shaped region where DNA is unwound for replication.

PCR

Polymerase Chain Reaction; amplifies specific DNA sequences.

Transcription Initiation

RNA polymerase binds to promoter to start transcription.

Translation Initiation

Ribosomal subunits assemble at start codon (AUG).

Codons

Three-nucleotide sequences on mRNA coding for amino acids.

Anticodons

Three-nucleotide sequences on tRNA complementary to codons.

Stop Codons

Codons that signal termination of translation.

Primary Protein Structure

Unique sequence of amino acids in a polypeptide.

Secondary Protein Structure

Coils and folds formed by hydrogen bonds.

Tertiary Protein Structure

3D shape formed by interactions of R groups.

Quaternary Protein Structure

Complex of multiple polypeptide chains.

Allosteric Proteins

Proteins that change shape upon binding of effectors.

Point Mutation

Change in a single nucleotide in DNA sequence.

Glycosylation

Addition of carbohydrates to proteins post-translationally.

Phosphorylation

Addition of phosphate groups to proteins for regulation.

Autosomal Dominant

One copy of an allele causes phenotype expression.

Autosomal Recessive

Two copies of an allele required for phenotype.

X-linked Inheritance

Traits linked to genes on the X chromosome.

Founder Effect

Reduced genetic diversity from a small founding population.

Gene Family

Group of related genes within an organism's genome.

Pseudogenes

Nonfunctional gene remnants; may arise from mutations.

Transposons

DNA sequences that can change positions in the genome.

Chromatin Remodeling

Modifications allowing access to DNA for transcription.

Dysmorphology

Study of congenital abnormalities and their patterns.

Gene Regulation

Mechanisms controlling gene expression levels.

Environmental Impact

External factors influencing gene expression and phenotype.