Olivia - molecular genetics

Flashcards covering essential vocabulary from the Molecular Genetics Unit.

Nucleic Acid

A biopolymer essential for all known forms of life; includes DNA and RNA.

DNA

Deoxyribonucleic acid, the molecule that carries genetic information.

RNA

Ribonucleic acid, involved in protein synthesis and regulation of gene expression.

mRNA

Messenger RNA, a type of RNA that carries genetic information from DNA to the ribosome.

tRNA

Transfer RNA, a type of RNA that helps decode mRNA into a protein.

rRNA

Ribosomal RNA, a structural component of ribosomes.

Nucleotide

The basic building block of nucleic acids, consisting of a phosphate group, a sugar, and a nitrogenous base.

Monomer

A single molecule that can bind to other similar molecules to form a polymer.

Polymer

A large molecule made up of repeating subunits (monomers).

Watson + Crick

Scientists known for discovering the double helix structure of DNA.

Rosalind Franklin

A scientist whose work with X-ray diffraction was critical in understanding the double helix structure of DNA.

Erwin Chargaff

A biochemist known for Chargaff's Rule, stating that the amount of adenine equals thymine and the amount of cytosine equals guanine in DNA.

Chargaff’s Rule

The principle that in DNA, the amount of adenine equals thymine and the amount of cytosine equals guanine.

Phosphate group

A functional group consisting of a phosphorus atom bonded to four oxygen atoms; part of the backbone of DNA and RNA.

Deoxyribose

The sugar molecule in DNA nucleotides.

Ribose

The sugar molecule in RNA nucleotides.

Nitrogenous base

A component of nucleotides that includes adenine, thymine, cytosine, guanine, and uracil.

Pyrimidine

A type of nitrogenous base that includes cytosine, thymine, and uracil.

Purine

A type of nitrogenous base that includes adenine and guanine.

Phosphodiester bond

The bond that connects adjacent nucleotides in a nucleic acid.

Double helix

The structure formed by double-stranded DNA, resembling a twisted ladder.

Antiparallel strands

Refers to the opposite orientation of the two strands of DNA.

Leading strand

The DNA strand that is synthesized continuously during DNA replication.

Lagging strand

The DNA strand that is synthesized in fragments during DNA replication.

5’ & 3’

The orientation of the two ends of a DNA or RNA strand.

Replication

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

DNA Helicase

An enzyme that unwinds the DNA double helix during replication.

Topoisomerase

An enzyme that relieves the tension in DNA ahead of the replication fork.

SSB proteins

Single-strand binding proteins that stabilize unwound DNA during replication.

RNA Primase

An enzyme that synthesizes a short RNA primer for DNA replication.

Primer

A short nucleic acid sequence that provides a starting point for DNA synthesis.

DNA Polymerase

An enzyme that synthesizes new DNA strands by adding nucleotides.

Exonuclease activity

The ability of DNA polymerase to remove nucleotides from the ends of DNA strands.

DNA Ligase

An enzyme that joins Okazaki fragments on the lagging strand of DNA.

Okazaki fragments

Short segments of DNA synthesized on the lagging strand during replication.

Semi-conservative

The method of DNA replication where each new molecule contains one original strand and one new strand.

Telomere

The protective end of a chromosome that shortens with each cell division.

Telomerase

An enzyme that extends the telomeres of chromosomes.

Transcription

The process of synthesizing RNA from a DNA template.

Initiation

The first step of transcription where RNA polymerase binds to the promoter.

Elongation

The process of RNA synthesis where RNA polymerase adds nucleotides to the growing RNA strand.

Termination

The process where transcription ends and RNA polymerase detaches from the DNA template.

RNA Polymerase

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

Transcription Factors

Proteins that help regulate the transcription of genes.

RNA Processing (Editing)

The modification of RNA before it is translated into a protein.

Splicing

The process of removing introns and connecting exons in RNA.

Spliceosome

A complex of proteins and RNA that carries out splicing.

Intron

A non-coding segment of RNA that is spliced out during processing.

Exon

A coding segment of RNA that is retained during processing.

Poly-A tail

A string of adenine nucleotides added to the 3' end of mRNA for stability.

5’ Cap

A modified guanine nucleotide added to the 5' end of mRNA for protection and recognition.

Translation

The process of synthesizing a protein from an mRNA template.

Codon

A sequence of three nucleotides on mRNA that codes for a specific amino acid.

Anticodon

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

Reading frame

The way nucleotides are grouped into codons to ensure correct translation.

Mutation

A change in the DNA sequence that can lead to changes in phenotype.

Single-gene mutation

A mutation that affects a single gene, including substitution and frameshift changes.

Substitution

A mutation where one base is replaced by another.

Frameshift

A mutation that shifts the reading frame of the genetic code due to insertion or deletion.

Insertion

A mutation where extra nucleotides are added to the DNA sequence.

Deletion

A mutation where nucleotides are removed from the DNA sequence.

Chromosomal mutation

A mutation that affects the structure or number of chromosomes.

Deletion (chromosomal)

A type of chromosomal mutation where a segment of the chromosome is lost.

Duplication

A chromosomal mutation where a segment is duplicated.

Inversion

A chromosomal mutation where a segment is reversed.

Translocation

A chromosomal mutation where a segment is moved to a different chromosome.

Sickle Cell

A genetic disorder caused by a mutation in the hemoglobin gene.

Mutagens

Agents that cause mutations in DNA.

Chromosomes

Structures made of DNA and protein that contain the genetic information.

Histones

Proteins that help package DNA into a compact, organized structure.

Chromatin

The form of DNA when it is not tightly coiled, allowing for gene expression and replication.