Definitions Flashcards
Central Dogma
The 2 step process (transcription and translation) by which the information in genes flows into proteins.
DNA - RNA - Proteins
Archaeon
One of the two divisions of prokaryotes, often found in hostile environments such as hot springs or concentrated in brine.
Bacterium
One of the two divisions of prokaryotes; some species cause disease.
Cell
The basic unit from which a living organism is made. Consists of an aqueous solution of organic molecules enclosed by a membrane.
Chloroplast
Specialized organelle in algae and plants which contains chlorophyll and serves as the site in which photosynthesis takes place.
Chromosome
Long, threadlike structure composed of DNA and proteins that carries the genetic information of an organism. It becomes visible as a distinct entity when a plant or animal cell prepares to divide.
Cytoplasm
Contents of a cell that are contained within its plasma membrane but, in the case of eukaryotic cells, contained outside the nucleus.
Cytoskeleton
A microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.
Cytosol
The aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended.
DNA
Deoxyribonucleic acid. The carrier of genetic information.
Electron Microscope
Instrument that illuminates a specimen using beams of electrons to reveal and magnify the structures of very small object, such as organelles and large molecules.
Eukaryote
An organism whose cells have distinct nucleus and cytoplasm
Evolution
The process by which different kinds of living organism are believed to have developed from earlier forms during the history of the earth.
Fluorescence Microscope
Instrument used to visualize a specimen that has been labeled with a fluorescent dye; samples are illuminated with a wavelength of light that excites the dye, causing it to fluoresce.
Genome
The complete set of genes or genetic material present in a cell or organism
Homologous
Describes genes, chromosomes or any structures that are similar because of their common evolutionary origin. It can also refer to similarities between protein sequences or nucleic acid sequences.
Micrometer
Unit of length equal to one millionth (10^-6) of a meter
Microscope
Instrument for viewing extremely small objects.
Mitochondrion
(plural = mitochondria) Membrane enclosed organelle, about the size of a bacterium, that carries out oxidative phosphorylation and produces most of the ATP in eukaryotic cells.
Model Organism
A living thing selected for intensive study as a representative of a large group of species.(Eg. the mouse representing mammals, a certain yeast representing unicellular eukaryotes and E. coli representing bacteria)
Nucleus
Prominent, rounded structure that contains the DNA of a eukaryotic cell.
Organelle
A discrete structure or sub-compartment of a eukaryotic cell that is specialized to carry out a particular function. (Eg. Mitochondria)
Photosynthesis
The process by which plants, algae, and some bacteria use the energy of sunlight to drive the synthesis of organic molecules from carbon dioxide and water.
Plasma Membrane
The protein-containing lipid bilayer that surrounds a living cell.
Prokaryote
Major category of living cells distinguished by the absence of a nucleus. Prokaryotes include the archaea and the eubacteria (commonly called bacteria)
Protein
Polymer built from amino acids that provides cells with their shape and structure and performs most of their activities.
Protozoan
(plural = protozoa) A free-living, non-photosynthetic, single-celled, motile eukaryote
Ribosome
Large macromolecular complex, composed of ribosomal RNAs and ribosomal proteins, that translates messenger RNA into protein.
RNA
Ribonucleic acid. Molecule produced by the transcription of DNA; usually single stranded. It’s a polynucleotide composed of covalently linked ribonucleotide subunits. It serves a variety of structural, catalytic and regulatory functions in cells.
Peroxisomes
Organelles which generate and degrade hydrogen peroxide and are the site of beta oxidation of fatty acids.
Lysosomes
Organelles which break down proteins and release them as amino acids. (Recycling organelle)
Reticulocyte
Immature RBC
Operon
A set of linked genes organised by one promoter
Transcription Factor/Regulatory Proteins
A protein that controls the rate of transcription of genetic information (gene expression) from DNA to messenger RNA, by binding to a specific DNA sequence and acting like a switch to control transcription. They can either activate or repress.
Gene expression
The process by which information from a gene is used in the synthesis of a functional gene product.
The promoter region
Binds the enzyme RNA polymerase and correctly orients the enzyme to begin its task of making an RNA copy of the gene.
Regulatory DNA sequences
Sequences in the gene which are used to switch the gene on or off. Nearly all bacterial and eukaryotic genes have this.
Operator
A short DNA sequence within an operon’s promoter region, which is recognized by a transcription regulator (repressor). When regulator binds it blocks access of RNA polymerase to the promoter (preventing transcription of operon)
Combinatorial control
The way groups of transcription regulators work together to determine the expression of a single gene. (Eukaryotic cells)
Induced Pluripotent Stem (iPS) Cells
Cells that look and behave like the pluripotent embryonic stem cells that derived from embryos