Biology 120 Notes (Part 21) Continuing the Discussion on Mutations and Starting Transcription, RNA Processing, and Translation

Transcription

________ is the first step of protein synthesis and occurs in the nucleus.

Initiation

________ occurs when RNA polymerase binds to a promoter.

Translation

________ takes place in the cytoplasm and is the last step of protein synthesis.

termination

In ________, the stop sequence causes the RNA polymerase to release the newly formed RNA strand.

Induced mutations

___________ are caused by mutagens (environmental factors that alter base composition of DNA.

DNA

________ is the template and is catalyzed by the enzyme polymerase.

Neutral mutations

________ do not affect an organisms fitness.

Mutations

________ can have different impacts on fitness.

tRNA molecules

________ transfer amino acids to the ribosomes.

Beneficial mutations

________ increase the fitness (ability to survive and reproduce) of an organism.

RNA strand

A newly created ________ is called a transcript.

Transcription

________ occurs in three steps which are: initiation, elongation, and termination.

Translation

________ involves all three types of RNA (mRNA, tRNA, and rRNA)

Mutations

________ can be spontaneous or induced.

https

/ www.britannica.com/science/DNA-polymerase

Transcription occurs in three steps which are

initiation, elongation, and termination

Cancer-causing mutagens

___________ are called carcinogens.

promotor

A ____________ is a region of DNA that defines the start of transcription, the direction of transcription, and which strand of DNA will be transcribed.

Modifications that need to be made before a pre-mRNA molecule leaves the nucleus are

These modifications include a modified guanine nucleotide called a cap being placed at the 5’ end, a chain of 150-200 adenine nucleotides being added to the 3’ end (this is called a poly-A tail), and introns must be excised by complexes called spliceosomes.

transcript

A newly created RNA strand is called a __________.