Vocab
The portions cut out during RNA editing are..
The remaining pieces are known as....
1. Introns 2. Exons
1.) What does mRNA do?
2.) What makes up an RNA nucleotide?
1.) carries instructions for polypeptide synthesis from nucleus to ribosomes in cytoplasm
2.) phosphate group
nitrogen base
ribose
How does deletion mutation differ from a substitution mutation>?
Deletion mutation occurs when a vase is lost from the codon. This shifts the reading frame, so all codons after that point of deletion are affected.
Substitution mutation occurs when a single base is replaced by a different base. this does not shift the reading frame!
how is an lac operon regulated
regulated by a repressor protein that binds to the lac operon site in absence of lactose. If lactose is present, repressor protein falls off the lac operon site so that the lac genes can be transcribed.
In eukaryotes, where does transcription take place? Where does translation take place?
transcription takes place in the nucleus, and translation takes place in the cytoplasm
Segments of DNA serve as templates to produce complementary RNA molecules is called.
What enzymes are involved in this process?
1. Transcription
2. RNA polymerase
Describe three main differences between RNA and DNA
1. RNA contains the sugar ribose instead of deoxyribose.
2. Normally single-stranded not double-stranded like DNA.
3. Contains Uracil instead of Thyamine
Changes in the DNA sequences that affect genetic information are known as what?
mutations
What was the difference between prokaryotes and eukaryotes in gene regulation?
prokaryotic gene expression occurs in the cytoplasm whereas a part of the eukaryotic gene expression occurs inside the nucleus while the rest occurs in the cytoplasm
Blocking gene expression by means of miRNA silencing complex is known as
RNA interference
Enzymes do what to chemical reactions?
Catalyze - speeds up reaction
What else might codons represent?
Besides the amino acids.
Stop and Start
Can mutations be beneficial? Explain
Yes mutation could produce a protein with a new or altered function that might be useful to an organism in a changing environment
What is the rearranged lactose called?
allolactose
what is the promoter called in eukaryotes
what binds to it
TATA box
transcription factors
What are anticodons?
Three unpaired bases in tRNA and they are complimentary to mRNA codons.
Binding site for RNA polymerase
Promoter
What does the operon consist of?
The promoter, Operator, and structural genes
How is gene expression controlled in prokaryotes
DNA binding proteins regulate genes by helping switch genes on or off before transcription
what is differentiation
cells become specialized in structure and function.
what is a polyploidy
condition when organism has extra set of chromosomes
Describes what happens in transcription
Enzyme RNA polymerase binds to DNA and separates the DNA strands. It then uses one strand of DNA as a template to assemble nucleotides into a complementary strand of RNA.
What are the three stop codons?
(UAG, UAA, and UGA)
What is the function of the lac repressor in E.coli?
Controls the production of enzymes needed to digest lactose. when lactose is absent and the enzymes are not needed, repressor proteins turn off genes so that these enzymes are not produced. when lactose is present (enzymes needed), lactose prevents the repressor proteins from turning off the genes so that the enzymes will be produced.
what are homeotic genes?
any of a group of genes that control the pattern of body formation during the early embryonic development of organisms.
"master control genes"