Gene Expression and Genetic Regulation

Flashcards covering key vocabulary and concepts from the lecture notes on gene expression and genetic regulation.

Gene Expression

Turning on a gene to produce RNA and protein.

Growth

Increase in the number of cells.

Differentiation

Cells becoming specialized.

Epigenetic Level

Regulation that occurs when the DNA is uncoiled and loosened from nucleosomes to bind transcription factors.

Transcriptional Level

Regulation that occurs when the RNA is transcribed.

Post-transcriptional Level

Regulation that occurs when the RNA is processed and exported to the cytoplasm after it is transcribed.

Translational Level

Regulation that occurs when the RNA is translated into protein.

Post-translational Level

Regulation that occurs after the protein has been made.

Enhancers

Regions that help increase or enhance transcription; can be located upstream, within, or downstream of a gene.

Negative Control

Stops transcription.

Positive Control

Promotes transcription.

Inductive Control

Induces (causes) transcription.

Repressive Control

Inhibits (prevents) transcription.

Operon

A cluster of functionally-related genes controlled by a shared operator.

Promoter

A binding site on the DNA where RNA polymerase attaches.

Operator

A binding site on the DNA where the repressor attaches.

Repressor

A protein that binds to the DNA (to the operator) to decrease transcription.

Inducible

Metabolite Present = Operon (Genes) On.

Repressible

Metabolite Present = Operon (Genes) Off

Positive Regulation

Operon ON if protein is present.

Negative Regulation

Operon OFF if protein is present .

Operon

Group of related genes.

Lactose Present

The enzyme binds to the repressor and removes it so transcription occurs.

Tryptophan Present

The product binds to repressor and keeps it in place so transcription does not occur.

lac operon

The repressor is released so that transcription of genes involved in digestion can occur.

trp operon

The repressor stays bound to the DNA to prevent transcription of genes involved in making it.

Operons

Clusters of bacterial genes.

Promoter (P)

Where RNA polymerase binds.

Operator (O)

Where the repressor binds.

Genes (G)

Group of genes involved in a specific pathway.

DNA Methylation

Attachment of methyl groups (-CH3) to cytosine.

Cell Differentiation

Development of different cells with specialized functions form tissues and organs.

Morphogenesis

Development of form in an organism.

Zygote Development

Genes expressed only when specific proteins are needed.

Totipotent Stem Cell

Has unlimited capability and has the ability to form extraembryonic membranes and tissues, the embryo itself, and all postembryonic tissues and organs.

Pluripotent Stem Cell

Capable of giving rise to most, but not all, tissues of an organism.

Multipotent Stem Cell

Committed to give rise to cells that have a specific function.

Stem Cells

Have the ability to divide for indefinite periods and to give rise to specialized cells.

Somatic Cells

Diploid cells that make up most of the human body, such as the skin and muscle.

Germ Cells

Any line of cells that give rise to gametes - eggs and sperm - and thus are continuous through the generations.

Stem Cells

Cells that can differentiate into specialized cells or divide to produce more stem cells.

Embryonic Stem Cells

Isolated from the inner cell mass of blastocysts.

Adult Stem Cells

Found in various tissues of adult organisms and act as a repair system.

Totipotent Cells

The ultimate stem cells; they have the potential to differentiate into any of the cells needed for an organism to grow.

Pluripotent Cells

Precursors to the fundamental tissue layers of the embryo.

Multipotent Cells

Stem cells that are slightly more specialized than pluripotent cells.

Transcription Factor

A protein that binds to specific genes on the DNA molecule and promotes or inhibits their transcription.