Prokaryotic and Eukoaryotic coding genes - structural differences

Question 1

what is a gene

Answer 1

a genetic unit containt info to make a functional product (RNA and /or protein)

Question 2

what info does a gene contain

Answer 2

structual = coding DNA

temporal = tells gene when to turn on (ie during devleopmental programmes)

positional = where to switch on (ie turned on in the liver and not the pancreas)

inducible = genes that are switched on or off by homones, nutrients, stress etc. e.g. insulin)

Question 2

prokaryotic gene organisation - role of promoter

Answer 2

defines transcription start site and its direction

at the end of it, theres a transcription start site
which is where RNA polymerase binds

Question 3

prokaryotic gene organisation - leaders and spacers

Answer 3

section of DNA that’s non translated (not mad#e into proteins)
copied to RNA but dont go any further

Question 4

prokaryotic gene organisation - cistrons

Answer 4

segment of DNA corresponding to one polypeptide

Question 5

are transcription start/stop sites the same and translation start/stop sites?

Answer 5

no

Question 6

what type of eukaryotic gene is used to make protein

Answer 6

eukaryotic class II (mRNA-encoding) genes

Question 7

what are the 2 sequence/regulatory elements in a euk gene

Answer 7

promoter - same function as in a prok
enhancer

Question 8

what is the strucural part on the gene made up of

Answer 8

introns - later gets removed from mature transcript
exons - in mature transcript
untranslated region - ie UTR

Question 9

what are the regions present in a transcribed euk strand

Answer 9

5’ UTR
Translated region
3’ UTR

SEE ONE NOTE FOR DIAGRAMS AND EXPLANATIONS idk how to write this shit

Question 10

what’s the problem with the relative size of eukaryotic genes compared to lower euk and prok?

Answer 10

can be quite large
most of it’s intergenic ie non coding

lower euk and prok are small and are more equal to amount of protein they produce, so not much excess

Question 11

key diff between euk and prok gene structure

Answer 11

prok have cistrons and spacers
euk have introns and exons

Question 12

pribnow box

Answer 12

5’ TTGACA - TATAAATG 3’
these are BEHIND the promoter region
and signal to rna pol where to bind onto

(abount 10 nucleotides down from TATAAATG)

Question 13

which is sense strand and which is antisnese

Answer 13

sense = coding strand (mRNA is a copy of this strand, with U instead of T ofc)

antisense = non-coding/template starnd