DNA Replication, Repair, and Recombination Overview

Mutation Rate

Frequency of mutations per cell generation.

Silent Mutation

Mutation that does not alter protein function.

Lactose Utilization Gene

Gene required for lactose metabolism in bacteria.

Glucose

Alternative sugar affecting mutation rate measurement.

Codon

Three-nucleotide sequence coding for an amino acid.

Amino Acid

Building blocks of proteins, specified by codons.

Bacterial Cell Generations

Cycles of bacterial reproduction, affecting mutation accumulation.

Average-sized Protein

Typically encoded by ~103 nucleotide pairs.

Germ Line Mutation Rate

Rate of mutations in reproductive cells.

C. elegans

Model organism for studying germ line mutations.

Fraction of Damaged Genes

Underestimates actual mutation rate due to silent mutations.

Nucleotide Change

Alteration in DNA sequence affecting genetic information.

Cell Survival

Impact of mutations on bacterial viability.

Energy Source

Substance used by cells for metabolic processes.

Protein Activity

Functionality of proteins affected by mutations.

Mutation Accumulation

Process of genetic changes over generations.

Repair Mechanisms

Biological processes correcting DNA mutations.

Recombination

Genetic process exchanging DNA between organisms.

Damaging Mutation

Genetic change impairing organism's function.

Bacterial Mutation

Genetic alteration occurring in bacterial DNA.

Genetic Information

Data encoded in DNA sequences.

Measurement Techniques

Methods for assessing mutation rates in organisms.

Complex Organisms

Multicellular entities with intricate genetic structures.

Glucose Presence

Condition affecting mutation rate measurement.

Codon Change

Alteration in DNA triplet coding for amino acid.

Amino Acid Change

Modification that may not affect protein activity.

1 in 10^6

Rate of mutation for average-sized proteins.

Bacterial Mutation Measurement

Determining mutation rates in bacterial populations.

Mutation Correction

Adjusting mutation rates for silent mutations.

DNA Repair

Mechanism correcting DNA damage.

Bacterial Survival

Ability of bacteria to live under stress.

Nucleotide Pairs

Building blocks of DNA sequences.

Generation Time

Time taken for one complete reproductive cycle.

Self-Fertilization

Reproductive process where an organism fertilizes itself.

Haploid Genome

Genome with a single set of chromosomes.

Cell Division

Process where a parent cell divides into daughter cells.

Germ-Line Mutation Rate

Rate of mutations occurring in germ-line cells.

Amino Acid Sequence

Order of amino acids in a protein chain.

Fibrinogen

Protein that converts to fibrin during blood clotting.

Fibrinopeptides

Peptides derived from fibrinogen, involved in clotting.

Stable Mutation

Permanent change in DNA sequence that is inherited.

Somatic Cells

Cells forming the body, not involved in reproduction.

Germ Cells

Cells that transmit genetic information to offspring.

Essential Proteins

Proteins necessary for survival and function of an organism.

Mutation Frequency

Rate at which mutations occur in a population.

Evolutionary Limitations

Constraints on complexity due to mutation rates.

DNA Sequencing

Technique to determine the nucleotide sequence of DNA.

Species Divergence

Point at which two species evolve from a common ancestor.

Indirect Estimates

Calculations based on comparative analysis rather than direct measurement.

Nucleotide Sequences

Specific order of nucleotides in a DNA strand.

Comparative Analysis

Method of comparing biological data between different species.

Deleterious Mutations

Mutations that negatively affect an organism's fitness.

400 Amino Acids

Typical length for proteins studied in mutation rate calculations.

Cancer

Uncontrolled cell proliferation due to genetic mutations.

DNA Fidelity

High accuracy in DNA replication and maintenance.

Nucleotide Change Rate

Approximately 1 change per 10 billion nucleotides.

Human Genome Size

Approximately 3 billion nucleotide pairs.

DNA Polymerase

Enzyme responsible for synthesizing new DNA strands.

Deoxyribonucleoside Triphosphates

Building blocks for DNA synthesis during replication.

Base-Pairing

Specific pairing of nucleotides in DNA strands.

Replication Machine

Complex of proteins that ensures accurate DNA replication.

Semiconservative Replication

Each new DNA helix contains one old and one new strand.

DNA Template Strand

Original strand used to guide synthesis of new DNA.

Hydrogen Bonds

Weak interactions that stabilize DNA base pairs.

Replication Fork

Y-shaped structure where DNA strands separate for replication.

Polymers

Large molecules made of repeating subunits, like DNA.

Nucleotide

Basic unit of DNA, consisting of a base, sugar, and phosphate.

Cell Proliferation

Increase in cell numbers through division.

Natural Selection

Process where advantageous traits increase in frequency.

Replication Rate

Speed of DNA synthesis, up to 1000 nucleotides per second.

Deoxyribonucleotide

Building block of DNA, added to primer strand.

Polynucleotide chain

A sequence of nucleotides linked together.

Primer strand

Initial strand that DNA synthesis builds upon.

Template strand

Existing DNA strand guiding new strand synthesis.

Deoxyribonucleoside triphosphate

Nucleotide precursor for DNA synthesis.

Antiparallel orientation

Opposite directional arrangement of DNA strands.

5'-to-3' direction

Direction of DNA strand growth during synthesis.

3'-to-5' direction

Direction opposite to DNA synthesis growth.

Radiolabeled DNA

DNA marked with radioactive thymidine for tracking.

Nucleotide addition reaction

Process of adding nucleotides to growing DNA strand.

Pyrophosphate

Byproduct of nucleotide addition, drives DNA synthesis.

Hydrolysis of pyrophosphate

Breakdown releasing energy for DNA synthesis.

High fidelity

Accuracy level of DNA replication, 1 mistake per 10^9 nucleotides.

Proofreading mechanisms

Systems ensuring accuracy during DNA replication.

Replication mechanisms

Processes involved in duplicating DNA strands.

Active zone of DNA replication

Region where DNA synthesis actively occurs.

Y-shaped DNA structure

Formation created by replication forks during synthesis.

Daughter DNA molecules

Newly synthesized strands resulting from replication.

Parental DNA helix

Original DNA strand serving as template.

Base Pairing

Specific hydrogen bonding between DNA bases.

Tautomeric Forms

Rare base variations affecting pairing stability.

Proofreading Mechanism

Correction process for mispaired nucleotides.

Exonucleolytic Proofreading

Error correction after nucleotide incorporation.

Okazaki Fragments

Short DNA segments synthesized on lagging strand.

3'-OH End

Required for DNA polymerase to elongate strands.

Energetically Favorable Pairing

Correct base pairing has higher binding affinity.

Conformational Change

Structural adjustment of polymerase during nucleotide binding.

Mismatch Incorporation

Incorrect nucleotide added to growing DNA chain.

Nucleotide Affinity

Correct nucleotides bind more strongly to polymerase.

Micrograph

Photographic representation of microscopic structures.