DNA Structure and Function

Flashcards covering key vocabulary and concepts related to DNA structure, function, and manipulation.

DNA

Deoxyribonucleic Acid - a macromolecule of hereditary that contains the genetic blueprint for life.

Chromosome

Supercoiled DNA and proteins

Histone

Protein that supercoils DNA

Nucleotide

The monomer unit of nucleic acid (DNA/RNA), composed of a sugar (pentose), a nitrogenous base, and a phosphate group.

Nitrogenous Base

A component of nucleotides (DNA and RNA). In DNA, these are Cytosine, Thymine, Adenine, and Guanine.

Antiparallel

The strands on a DNA double helix have their nucleotides oriented in the opposite direction to one another.

Adenine

A purine nitrogenous base in DNA that pairs with Thymine.

Thymine

A pyrimidine nitrogenous base in DNA that pairs with Adenine.

Guanine

A purine nitrogenous base in DNA that pairs with Cytosine.

Cytosine

A pyrimidine nitrogenous base in DNA that pairs with Guanine.

Purine

A nitrogenous base composed of a double carbon ring (Adenine and Guanine).

Pyrimidine

A nitrogenous base composed of a single carbon ring (Thymine and Cytosine).

Semiconservative replication

A form of replication in which each original strand of DNA acts as a template for building a new side; one strand of each new copy goes into a new daughter cell during cell division.

Chromatin

Nuclear DNA and proteins

Gene

A section of DNA on a chromosome that contains the genetic code of a protein.

Base pair

Two nitrogenous bases connected by a hydrogen bond (A with T, G with C).

Phosphodiester bond

A bond that is responsible for polymerization of nucleic acids by linking sugars and phosphates of adjacent nucleotides

Hydrogen bond

A type of weak bond involving the 'sandwiching' of a hydrogen atom between two fluorine, nitrogen, or oxygen atoms; especially important in the structure of nucleic acids and proteins

Medium

A suspension or gel providing nutrients and environment needed for cells to survive.

Lysis

The breakdown or rupture of cells.

R plasmid

A type of plasmid that contains a gene for antibiotic resistance.

Transformed

Cells that have taken up foreign DNA and started expressing the genes on the newly acquired DNA.

Vector

A piece of DNA that carries one or more genes into a cell; usually circular as in plasmid vectors.

Operon

A section of prokaryotic DNA consisting of one or more genes and their controlling elements.

RNA polymerase

An enzyme that catalyzes the synthesis of complementary RNA strands from a given DNA strand.

Promoter

The region at the beginning of a gene where RNA polymerase binds; promotes recruitment of RNA polymerase and other factors required for transcription.

Operator

A region on an operon that can either turn on or off expression of a set of genes depending on the binding of a regulatory molecule.

Agar

A solid media used for growing bacteria, fungi, plant, or other cells.

Broth

A liquid media used for growing cells.

Autoclave

An instrument that creates high temperature and high pressure to sterilize equipment and media.

Enhancer

A section of DNA that increases the expression of a gene.

Silencer

A section of DNA that decreases the expression of a gene.

Transcription factors

Molecules that work to either turn on or off the transcription eukaryotic genes.

Intron

The region on a gene that is transcribed into an mRNA molecule but not expressed in a protein.

Exon

The region of a gene that directly codes for a protein; it is the region of the gene that is expressed.

Histones

The nuclear proteins that bind to chromosomal DNA and condense it into highly packed coils.

Bacteriophages

The viruses that infect bacteria.

Gene therapy

The process of treating a disease or disorder by replacing a dysfunctional gene with a functional one.

Recombinant DNA Technology

Methods to create new DNA molecules by piecing together different DNA molecules.

Site-specific mutagenesis

A technique that involves changing the genetic code of an organism in certain sections on a particular DNA code.

Gel electrophoresis

A process that uses electricity to separate charged molecules, such as DNA fragments, RNA, and proteins, on a gel slab.

Agarose

A carbohydrate from seaweed that is widely used as a medium for horizontal gel electrophoresis.

Polyacrylamide

A polymer used as a gel material in vertical electrophoresis; used to separate smaller molecules, like proteins and very small pieces of DNA and RNA.

Ethidium bromide

A DNA stain (indicator); glows orange when it is mixed with DNA and exposed to UV light; abbreviated EtBr