Gene Expression and Regulation

The metabolic product interferes directly with ribosome function during translation of these enzymes.

The end product acts as a corepressor that activates a repressor protein which binds to the operator site and blocks RNA polymerase.

The surplus metabolite enhances allosteric activation of transcription factors for unrelated genes' promoters.

The end product increases degradation rate of mRNA coding for these enzymes through ribonuclease activity.

tRNA

DNA polymerase

rRNA

mRNA

A protein that turns on RNA polymerase

Activators are not present in positive gene regulation

A protein that induces repressors to make them inactive so transcription occurs

A protein that binds upstream of the DNA stimulates the transcription of a gene

Greater utilization of stored fats and proteins for cellular energy needs.

Increased reliance on anaerobic pathways like lactic acid fermentation.

Reduced energy capture for synthesizing carbohydrates via photosynthesis.

Elevated rates of photorespiration resulting in more efficient growth.

Only males are affected by the trait.

Affected individuals are usually homozygous dominant.

The trait appears in every generation.

Most affected individuals have unaffected parents.

Corepressors enhance production from transcription

Corepressors bind themselves to the promotor and halt transcription

Corepressors cooperate with repressors to switch an operon off

Corepressors terminate the transcription process

Needle-like leaves in tropical rainforests prevent water saturation while promoting rapid nutrient cycling.

Leaves with thicker cuticles prevent water loss but reduce gas exchange needed for photosynthesis.

Smaller leaves optimize water usage in cold environments enhancing nutrient recycling and productivity.

Broad leaves increase photosynthesis in arid environments but may lead to water loss affecting nutrient cycling negatively.

Active

Inducible

Repressible

Inactive

Negative gene regulation

DNA methlyation

Transcription initiation

Positive feedback regulation

Removing exons from pre-mRNA facilitates binding to ribosomes for translation initiation.

Adding a poly-A tail to mRNA molecules aids in their stability and exit from the nucleus.

Shortening mRNA strands increases their degradation rate to prevent overproduction of proteins.

Attaching amino acids directly to mRNA provides quicker response times during translation.