🧪cellular control🧪

what is an operon?

a cluster of genes under the control of a promoter

hox gene mutations are what?

often lethal

what gene expression is being controlled when dna is more tightly wound during cell division?

transcriptional

what processes are important in determining a body plan?

apoptosis and mitosis

what is needed to start transcription?

rna polymerase

what does rna need to bind to?

a promoter

what is an operator?

a part of dna where a repressor can bind

what happens if a repressive binds to an operator?

blocks rna polymerase from working

how does lactose allow lactase to be made?

binds to repressor to change its shape so it cannot bind to the operator

what does it mean for a gene to be expressed?

the gene can be used to make something functional

can environmental factors affect transcription factors?

yes

what does an operon involve?

a regulated cluster of genes with a promoter and an operator

what are introns?

rna portions that are removed

what are exons?

remaining rna used in translation

how can eIF-2 be regulated?

phosphorylated and then translation cannot be started

where do prokaryotic cells usually have gene regulation?

transcription

where do eukaryotes usually have gene regulation?

transcription and translation and in between

what can cancer cells do?

express genes not needed and not express needed genes

what are the 2 general types of mutation?

chromosomal and gene

what are the 3 types of gene mutation?

substitution

insertion

deletion

what do insertion and deletions cause?

a frame shift

what is a mis-sense substitution?

where it causes a different amino acid to be coded for

what is a nonsense substitution?

causes a stop codon to be created

what are the 4 types of chromosomal mutations?

deletion

duplication

translocation

inversion

what do transcription factors bind to?

operons

mRNA strands containing introns and exon are called?

primary mRNA transcripts (pre-mRNA)

how are introns removed?

splicing

when introns are removed, what is the mRNA called?

mature mRNA

how is cAMP produced?

molecules bind to cell membranes

how does cAMP activate proteins?

alters their 3D structure

what is a body plan?

general structure of an organism

what are hox genes?

genes that code for proteins that control body plan development

what are homeobox sequences?

sequences that have changed very little during evolution of different organisms

what do homeobox sequences code for?

homeodomain

what does the homeodomain do?

bind to specific sites on DNA enabling the protein to work as a transcription factor

what is apoptosis?

programmed cell death

what are the steps once apoptosis has been triggered?

enzymes inside the cell break down cell components, cell shrinks and begins to fragment, phagocytes engulf and digest cell fragments

how is gene expression regulated at the transcriptional level?

transcription factors

how is gene expression regulated at post transcriptional level?

splicing

how is gene expression regulated at post translational level?

activation of proteins

what do insertions or deletions cause?

frame shift

how is translation controlled?

splicing

why are mice good for researching hox genes?

high reproductive rate

more similar to humans

give an example where apoptosis should’ve occurred but didnt?

people with fingers that are stuck together

how is mature mRNA produced?

primary RNA has introns removed via splicing

how do hox genes affect development of body plans?

the homeobox sequences on the hox genes code for a particular region of a protein (homeodomain) which acts as a transcription factor to activate or repress a developmental gene