Biology 30 - Unit 2 Booklet 1: Molecular Biology (Terms)

DNA (Deoxyribonucleic Acid)

A weakly acidic substance in the nuclei of cells that is the hereditary material of a cell

Nucleotide

The simplest subunit in DNA/RNA made up of a sugar, phosphate, and nitrogenous base

Chargaff’s Rule

The rule of percentages in a DNA strand stating that the percentage of A is equal to the percentage of T, and the percentage of G is equal to the percentage of C

Antiparallel

A term describing the opposite movement of complementary DNA strands due to their opposing directions

Semi-Conservative Replication

The process in which a single strand of DNA nucleotides acts as a template for the formation of a complimentary daughter strand, where the daughter strand is made up of one half old strand and one half new strand

Helicase

An enzyme that unzips the hydrogen bonds between the nitrogenous bonds in the double helix

DNA Polymerase 1

The enzyme that removes RNA primers and replaces them with appropriate nucleotides

DNA Polymerase 3

The enzyme that synthesizes new strands of DNA by linking together free nucleotides with bases complementary to the template strand

RNA Primer

A short segment that is attached to the template DNA strand that guides DNA polymerase 3 to its starting point

RNA Primase

An enzyme that creates RNA primers

Okazaki Fragments

The short fragments of nucleotides by which the lagging DNA strand is synthezsized

Protein

A long chain of specific sequence of amino acids

Transcription

The first step of protein synthesis involving splitting DNA and making a copy of mRNA

Translation

The second step of protein synthesis involving making proteins by using tRNA to bring amino acids as described by mRNA

RNA (Ribonucleic Acid)

A weakly acidic substance found in the cytoplasm of cells that is responsible for protein synthesis

Gene

A discrete unit of heredity coded for be a specific sequence of DNA bases that produces a polypeptide protein

Chromosome

A structure of nucleic acid and proteins that carries genetic information

Codon

Three nucleotides each containing its own nitrogenous base that codes for one amino acid on mRNA

Redundancy

The existance of several codons for each amino acid to allow room for error and stability form poor mutations

Frame Shift

A change in all subsequent codons resulting from an insertion or deletion of a nucleotide in an RNA sequence

Mutation

A permanent, inhertiable change in the genetic material (DNA) that cause changed cells

Somatic Mutation

A mutation in the body cells

Germ Line Mutation

A mutation in the sex cells that appears in offpspring

Beneficial Mutation

A mutation that gives organisms a selective advantage that tends to become more common over time and leads to new evolutionary change due to their beneficial nature allowing organisms to pass on genes

Harmful Mutation

A mutation that reduces an individual’s fitness that tends to be selected against and occurs at low rates due to their destructive nature often causing death of organisms

Neutral Mutation

A mutation that gives an individual no benefit or cost because it is redundant or insignificant to its fitness

Insertion Mutation

A mutation occuring when an extra nucleotide is inserted into the DNA, causing a frame shift of all subsequence nucleotides to the right

Deletion Mutation

A mutation occuring when an existing nucleotide is deleted from the DNA, causing a frame shift of all subsequence nucleotidesto the left

Substitution Mutation

A mutation occuring when an existing nucleotide is substituted for another, causing a point mutation that changes one created amino acid

Recombinant DNA

A genetic engineering technique to combine DNA from 2 or more samples that determines gene expression by recombining gene segments in vitro

Plasmid

Bacterial DNA that is used to create recombinant DNA

Ribosome

A two subunit particle found in the cytoplasm that attaches to mRNA and binds tRNA in order to complete translation

mRNA (Messenger RNA)

RNA responsible for transcribing a gene for protein synthesis

tRNA (Transfer RNA)

RNA responsible for bringing the correct amino acid during translation that corresponds to each mRNA codon

nDNA (Nucleic DNA)

DNA found within the nucleus of a cell that encodes for most of the genome

mtDNA (Mitochondric DNA)

DNA found within the mitochondria of a cell originiating exclusively from an egg cell that helps with ATP production

RNA Polymerase

An enzyme that unwinds the double stranded DNA during transcription and adds the appropriate mRNA nucleotide to create the necessary mRNA strand

Restriction Enzyme

An enzyme resmbling genetic scissors that isolates and cuts desired genes out of DNA