Cellular Control Flashcards
What is a gene?
A section of DNA that codes for one or more polypeptides
What is 4 to the power of three?
64
out of mRNA and tRNA, which one has the codon, and which one has the anticodon?
mRNA has the codon and tRNA has the anticodon
What is a mutation?
A change in the amount of or arrangement of genetic material in a cell
What is a substitution mutation?
Where bases are substituted out for another
What is a deletion mutation?
One base is deleted
What is an addition mutation?
One base is added
What is a duplication mutation?
The codon its duplicated
What is an inversion mutation?
Bases in a codon are inverted
What types of mutations cause frame shifts?
Deletion and addition mutations
What is an example of a beneficial mutation?
Bacterial resistance
What is an example of a harmful mutation
Proteins folding incorrectly – cystic fibrosis
What happens in a neutral mutation?
The amino acid sequence doesn’t change
What is an operon?
A section of DNA that controls structural genes, control elements and regulatory genes
What do structural genes code for?
Useful proteins such as enzymes
What letter is the start of the lac operon and what does it do?
I - codes for transcriptional factors
What does P stand for in the lac operon and what does it do?
Promoter - it is the control element that RNA polymerase binds to
What does O stand for in the lac operon and what does it do?
Operator - the transcription factors bind to it
What are Z and Y in the lac operon and what are they?
Z is beta galactosidase and Y is lactose permease - they are structural genes
What is a transcription factor?
A protein that binds to DNA and switches genes on or off by increasing or decreasing the rate of transcription
What is the transcription factor in the Lac operon?
Repressor
What happens to the lac operon when there is lactose present?
Lactose binds to the repressor and doesn’t bind to the operator
What happens to the lac operon when lactose is not present?
The repressor binds to the operator and blocks transcription
What does cAMP do?
Change the shape of the active site
What does a homeobox gene code for?
Proteins that control the development of a body plan
What is a apoptosis?
Programmed cell death
How does apoptosis happen?
1) The cell produces enzymes to breakdown important parts of the cell
2) the cell is then engulfed by phagocytosis
What is the hayflick limit?
The amount of times a cell can divide before it dies - 52
What are the two types of cell that aren’t affected by the hayflick limit?
Stem cells and cancer cells
What is an example of apoptosis in fetal development?
The splitting of fingers
What are the two stages involved in protein synthesis?
Transcription and translation
