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Gene expression
The overall process by which genetic information flows from genes to proteins
Gene regulation
mechanisms that turn on or turn off genes - carried out through short stretches of DNA that turn all three genes on and off at once, coordinating their expression.
Operon
a cluster of related genes and sequences that control them
Operator
control sequence between the promoter and the enzyme genes
repressor protein
binds to the operator and physically blocks the attachment of RNA polymerase to the promoter
promoter
the (control sequence) site where the enzyme RNA polymerase attaches and initiates transcription.
RNA polymerase
An enzyme that links together the growing chain of RNA nucleotides during transcription, using a DNA strand as a template.
Lac operon
three lactose-digesting genes are adjacent in the DNA and turned on and off as a single unit.
Eukaryotic gene structure
segments of coding sequences (exons) interrupted by noncoding sequences (introns).
DNA enhancer
noncoding DNA control sequences
DNA silencers
A eukaryotic DNA sequence that inhibits the start of gene transcription; may act analogously to an enhancer, binding a repressor.
Transcription factors
In the eukaryotic cell, a protein that functions in initiating or regulating transcription. Transcription factors bind to DNA or to other proteins that bind to DNA
Activators
proteins that turn genes on by binding to DNA. Activators act by making it easier for RNA polymerase to bind to the promoter.
DNA packing
prevent gene expression by preventing RNA polymerase and other transcription proteins from binding to the DNA
Barr bodies
inactivated X chromosome; compacted X chromosome
X chromosome inactivation
In female mammals, one X chromosome in each somatic cell is highly compacted and almost entirely inactive.
Homeotic genes
Master control genes- regulate groups of other genes that determine what body parts will develop in which locations
Small RNAs
miRNAs- small single stranded RNA molecules that can bind to complementary sequences on mRNA molecules
siRNAs- carries out RNA interference which blocks gene expression
Signal transduction
1. The signaling cell secretes the signal molecule
2. This molecule binds to a specific receptor protein embedded in the target cell’s plasma membrane.
3. The binding activates a signal transduction pathway consisting of a series of relay proteins within the target cell. Each relay molecule activates the next.
4. The last relay molecule in the series activates a transcription factor © 2019 Pearson Education, Inc. A cell-signaling pathway that turns on a gene (part 2: activated transcription factor to new protein) Nucleus Transcription mRNA New protein 6 Translation 5
5. Activation of transcription factor triggers transcription of specific gene
6. Translation of the mRNA produces a protein that can then perform the function originally called for by the signal.
Cloning
The production of multiple copies of a gene.
Reproductive cloning
Using a body cell from a multicellular organism to make one or more genetically identical individuals.
Therapeutic cloning
The cloning of human cells by nuclear transplantation for therapeutic purposes, such as the replacement of body cells that have been irreversibly damaged by disease or injury.
Oncogene
a gene that causes cancer
Proto Oncogene
a normal gene with the potential to become an oncogene - code for growth factors (proteins that stimulate cell division)
Tumor suppressor gene
Genes whose products inhibit cell division - proteins they encode normally help prevent uncontrolled cell growth
Inherited cancer
An individual inheriting an oncogene, or a mutant version of a tumor-suppressor gene is a step closer to accumulating the necessary mutations for cancer
