DNA and The Gene: Synthesis and Repair

A collection of vocabulary flashcards covering key terms and concepts related to DNA structure, synthesis, and repair.

Gene

A segment of DNA that contains the instructions for making a specific protein.

DNA

Deoxyribonucleic acid, the molecule that carries genetic information.

Chromosomes

Structures within cells that contain DNA and protein.

Antiparallel

The orientation of the two DNA strands in opposite directions.

Double Helix

The structure formed by two strands of DNA twisted around each other.

DNA Polymerase

An enzyme that synthesizes new strands of DNA from a template.

Semiconservative Replication

The method of DNA replication where each new double helix has one old strand and one new strand.

Phosphodiester Bond

The bond between the sugar and phosphate groups in the DNA backbone.

Leading Strand

The DNA strand synthesized continuously toward the replication fork.

Lagging Strand

The DNA strand synthesized discontinuously away from the replication fork.

Okazaki Fragments

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

Primer

A short segment of RNA or DNA that provides a starting point for DNA synthesis.

DNA Ligase

An enzyme that joins Okazaki fragments to create a continuous DNA strand.

Telomere

The repetitive nucleotide sequences at the ends of linear chromosomes.

Telomerase

An enzyme that extends the telomeres of chromosomes to prevent them from shortening.

Exonuclease

An enzyme that removes nucleotides from the end of a DNA strand.

Mismatch Repair

The repair process that corrects mismatched bases after DNA synthesis.

DNA Damage

Alterations to the DNA structure caused by environmental factors that can lead to mutations.

Xeroderma Pigmentosum

A rare genetic disorder that impairs the ability to repair DNA damage caused by UV light.

Nucleotide Excision Repair

A DNA repair mechanism that removes damaged nucleotides and replaces them with the correct bases.

Hydrogen Bonds

Weak bonds that hold the complementary pairs of nitrogenous bases together in DNA.

Deoxyribonucleotide

A building block of DNA that contains deoxyribose sugar and a nitrogenous base.

Replication Fork

The Y-shaped region where the DNA double helix is unwound for replication.

Single-Strand DNA-Binding Proteins (SSBPs)

Proteins that attach to separated DNA strands to prevent them from re-annealing.

Topoisomerase

An enzyme that relieves the tension in the DNA strand during replication.

Primase

An enzyme that synthesizes RNA primers for DNA replication.

Complementary Base Pairing

The specific hydrogen bonding between adenine & thymine and guanine & cytosine.

5' End

The end of a DNA strand with a free phosphate group.

3' End

The end of a DNA strand with a free hydroxyl (OH) group.

Bidirectional Replication

The process by which replication proceeds in both directions from a single origin.

Origin of Replication

The specific location where DNA replication begins.

Error Rate

The frequency of mistakes made during DNA replication.

Proofreading

The process by which DNA polymerase checks and corrects errors during DNA synthesis.

RNA Primer

An RNA strand used as a starting point for DNA synthesis.

Continuous strand

Another name for the leading strand that is synthesized in one piece.

Discontinuous Strands

Strands that are synthesized in short segments, specifically the lagging strand.

DNA Repair Genes

Genes that encode proteins responsible for repairing DNA.

Tumor

An uncontrolled proliferation of cells that can resulted from DNA mutations.

Eukaryotic Chromosomes

Linear chromosomes found in eukaryotic cells that contain multiple origins of replication.

Prokaryotic Chromosomes

Circular chromosomes found in prokaryotic cells where replication initiates at a single origin.

Thymine Dimer

A type of DNA damage caused by UV light where adjacent thymine bases bond incorrectly.

Cell Cycle

The series of phases that a cell goes through to replicate and divide.

Hydroxyl Group

An oxygen atom bonded to a hydrogen atom, which is found at the 3' end of DNA.

Nucleotide Replacement

The mechanism that replaces damaged nucleotides during DNA repair.

Genetic Information

The information encoded in DNA that is vital for the development and functioning of organisms.

Nitrogen-Containing Bases

The bases adenine, thymine, guanine, and cytosine that pair to form the rungs of the DNA ladder.

Replication Bubble

A region of unwound DNA where replication is occurring.

Energy-Releasing Reactions

Biochemical reactions that release energy, important for driving DNA synthesis.

Substrates (reactants)

The starting materials in a chemical reaction, in this case, deoxyribonucleoside triphosphates.