Ch4 Genetics Flashcards
Types of base subsitution
1- missense mutation : change the arrangement of amino acids
2-nonsense mutation: generate a stop codon leads to short protien
Types of mutation
1- base substitution
2- frameshift mutation
3-transposons
How nitrous acid and alkylating agents make a mutation
Making hydrogen bond in wrong bases
How 5-bromouracil making a mutation?
It iserted in thymine place and bind with guanine and make hydrogen bonds between G-G بدال ما يكون بين A-T
(Shift base pair)
How benzpyrene cause mutation ?
From smoke and tobacco cause frameshift mutation and its carcenogensn
What is 3 ways X-rays damaged DNA?
have a high energy :
1-produce free radicals that attack nitrogen bases
2-change in base electrons leads to change in hydrogen bonds between bases
3-breaking the covalent bond between phosphate and ribose in DNA
How ultra-violet cause DNA damage?
Have low energy than X-rays
That makes cross linking between 2 pyramidens to form thymine dimer lead to enable DNA replication.
What is controlled conjugation process?
Fertility plasmid(F factor) يحمل الجينات للبروتينات المطلوبة لعملية الconjugation
What is the most important gene for conjugation?
Pilin ; that forms sex pilli the conjugation tube
High frequency recombination cells(Hfr)
Some F+ cells have their F plasmid integrated into the bacterial DNA and thereby acquire the capability of transferring the chromosome into another cell.
Bacteria that encode resistance plasmids (beta lactemase):
1-staphylococcus ureos
2-escherichia colli
3-klebsiella pneumoniae
Transduction process depends on:
Bacterial virus(bacteriophage)
What means in “lysogenic conversion”?
When a recipent cell take a new traitصفة by bacteriophage integrate with its DNA
Bacteria are encoded by bacteriophage and transferred by transduction:
Streptococcus biogenes
Bacteria uptake DNA from environment by transformation process:
1-haemophellus
2-neissria
3-streptococci
