Genome packaging

Question 1

Comparison of eukaryotes and prokaryotes

Answer 1

single chromosomes in prok. while eukaryotes have multiple chromosomes.
Compact DNA in pro and much more compact density in euk.
more DNA than proteins (nucleoid) in prok. while there is an equal distribution in eukaryotes of proteins and DNA (nucleus)

Question 2

Do prokaryotes have histones?

Answer 2

No, eukaryotes do as this is the vehicle that drives compact DNA

Question 3

Nucleoid

Answer 3

round/oval shaped mass, coiled domains, extend from centre that looks like a hairbrush

Question 4

What does negative supercoiling do?

Answer 4

wraps around the other way which helps DNA packaging

Question 5

One negative super coil wind

Answer 5

every 20 helical wind

Question 6

Domains are repetitive DNA sequences with REPS

Answer 6

Repeated extragenic palindrome sequences

Question 7

What associates with REPs

Answer 7

DNA binding proteins where the ends are brought together like a loop

Question 8

What is the function of DNA gyrases?

Answer 8

binds to REPs which provides the necessary super coiling

Question 9

Describe the three levels of DNA organisation in prokaryotes

Answer 9

Level 1: DNA double helix in protein
Level 2: Supercoiled domain , gyrase and protein complex. they all form an anchor loop
Level 3: loop domain structure of bacterial chromosomes-bacterial cell with organised DNA

Question 10

Describe the gene organisation (occurs in clusters)

Answer 10

Genes: ribosomal RNA+ tRNA Found: OriC- highest amount of transcription with a higher turnover rate

Question 11

Describe the five levels of DNA organisation in eukaryotes

Answer 11

Level 1, level 3, level 4; similar to prokaryotes with nucleosomes

Differences:
Level 2:nucleosome packaged in rosettes
Level 5: condense chromosome

with negative supercoiling in level 4 and 5

Question 12

One gene one protein hypothesis

Answer 12

minimal medium used to give a microorganism the compound that it cannot produce itself
No growth- mutation, used to identify pathway

Question 13

Central dogma

Answer 13

DNA poly. is the main enzyme involved in replication

Transcription:
RNA poly. ssRNA having a similar sequence to one of two strands of dsDNA

Translation
Ribosomes that yield corresponding AA sequences and folds into prescribed functional protein structure