Does genetic material have any error detection/correction?

[OS]

what the topic asks

 

[Mday]

yes, there are proteins that do do error detection and correction (correction is usually destroying the molecule). i am sure you'll find information if you did a search in google. but there are errors that cannot be repaired.

oddly enough, I learned that over teh summer by watching pbs.

 

[SuperTool]

Does genetic material have any error detection/correction?

Yes, it's called evolution. Errors get discarded. Unless they are for the good.

 

[kinase01]

Genetic material, does have error detection/correction. When DNA is copied (ie during cell division) the process is carried out by a DNA polymerase enzyme which copies the DNA molecule and proofreads as it does so. There are also other enzymes (inc DNA polymerase) which proofread and repair miscopied DNA and which can repair damaged DNA. See http://www.web-books.com/MoBio/Free/Ch7G.htm for a quick technical look at some of the mechanisms. There are also links to other sources of info.

 

[Eug]

Originally posted by: kinase01
Genetic material, does have error detection/correction. When DNA is copied (ie during cell division) the process is carried out by a DNA polymerase enzyme which copies the DNA molecule and proofreads as it does so. There are also other enzymes (inc DNA polymerase) which proofread and repair miscopied DNA and which can repair damaged DNA. See http://www.web-books.com/MoBio/Free/Ch7G.htm for a quick technical look at some of the mechanisms. There are also links to other sources of info.

Indeed, some diseases occur because of defects in error detection. Knock out error detection, and mutation rates go up --> higher rates of cancer.

 

[Mday]

Originally posted by: SuperTool

Does genetic material have any error detection/correction?

Yes, it's called evolution. Errors get discarded. Unless they are for the good.

no, i think errors tend to propogate.

 

[CTho9305]

Originally posted by: Mday

Originally posted by: SuperTool

Does genetic material have any error detection/correction?

Yes, it's called evolution. Errors get discarded. Unless they are for the good.

no, i think errors tend to propogate.

Really bad errors = death = no propagation
less bad (or recessive) errors can hang around
good errors stay and often spread.

There is a little bit of error correction that happens during cell divisions, but IIRC it isn't very good.

 

[Jeff7]

Originally posted by: Mday

Originally posted by: SuperTool

Does genetic material have any error detection/correction?

Yes, it's called evolution. Errors get discarded. Unless they are for the good.

no, i think errors tend to propogate.

You can't base that on humans either - human evolution is basically stopped, as there's not nearly as much natural selection as there once was. Weak genes are allowed to propagate freely.

Also, there's something in cells that is supposed to destroy the cell if it's damaged; can't remember the name of the thing, or much about it - that was 10th grade biology; at least I think it was 10th grade.

 

[Evadman]

Originally posted by: Mday
yes, there are proteins that do do error detection and correction (correction is usually destroying the molecule). i am sure you'll find information if you did a search in google. but there are errors that cannot be repaired.

DNA is made up of 4 specific "parts" aranged in certain pairs, 2 "parts" on each section. errors will be found and distroyed of the paris do not match from the original strand. but it will not catch reversals; where the 2 sets switch orentation.

Sorry for the super general explanation, but it has been many many years since biology.

 

[Mark R]

There are a number of error correction mechanisms which operate when DNA is duplicated.

There are specific proteins that look for incorrect pairings and unpaired bases. Additional mechanisms then take over to ensure that these are corrected.

In E. coli bacteria, DNA replication errors occur about 1 in 100,000 bases. However, these are immediately proof-read, with approx 1% getting missed - the result is approx 1 error in 10,000,000 bases. The error detection and repair mechanisms can repair incorrect DNA with approx 99% effectivness. So total error rate is about 1 error per 10^9 bases.

What is interesting is that the amount of error correction is very important for survival. Research into bacteria has discovered unusual mutant strains where the error correction activity is abnormal. One strain called 'mutator' has very little error correction, and 'anti-mutator' has extremely active error correction - neither of these are common in the wild.

The anti-mutator strain spends so much time and energy proof-reading the DNA and triggering repair mechanisms due to 'false alarms', that they get driven out by more normal strains. The mutator strain replicates quickly but excessive numbers of the resultant population suffer damaging mutations and do not survive.

 

[imhotepmp]

Our DNA is constantly being damaged by any number of environmental factors such as carcinogens, UV, free radicals, etc and if we did not have a way to correct this damage then we wouldn't live to long. Also, as mentioned before, mistakes are made during replication and these errors are corrected by polymerase itself. Bacteria are much better at error correction compared to humans, allowing on average only one mutation per 10^9 base pairs, while we have one error per 10^5 base pairs. This is because bacterial polymerase contains an additional 3'-5' exonuclease activity that we lack. However, this higher mutation rate is countered by the fact that approximately 95-99% of our DNA is non-coding sequence, ofter incorrectly termed 'junk-DNA'. Non-coding seqeunce means that those regions do not code for genes, and can suffer mutations without penalty. Bacteria having a much smaller genome, combined with the fact that nearly 100% of its DNA is coding sequence(in fact in some species genes may overlap one another), has to have a better correction system or they wouldnt last too long.

DNA is made up of 4 specific "parts" aranged in certain pairs, 2 "parts" on each section. errors will be found and distroyed of the paris do not match from the original strand. but it will not catch reversals; where the 2 sets switch orentation.

These parts are called nucleotides and consist of Adenine, Guanine, Thymine, Cytosine(there are others but are less frequent) DNA consists of pairs of these bonded together(Adenine binds to thymine and Guanine binds to cytosine, hence AT-GC). If a mismatch occurs say, AC, then this will be detected and the correct base will be matched.

Hope I wasnt too long winded, and I answered your correction.

Imouthes

 

[nugglife4me]

Originally posted by: Jeff7

Originally posted by: Mday

Originally posted by: SuperTool

Does genetic material have any error detection/correction?

Yes, it's called evolution. Errors get discarded. Unless they are for the good.

no, i think errors tend to propogate.

You can't base that on humans either - human evolution is basically stopped, as there's not nearly as much natural selection as there once was. Weak genes are allowed to propagate freely.

I have pondered this too for awhile. seems as if in the not too distant future we will all be born with
lots of "pre-dispositions" to genetic deformities for this very reason. with advents in medical science, people with abnormalities that would normally not propogate are doing so freely and "polluting" the rest of the gene pool. having said that, I think this is where genetic engineering is gonna overcome the social acceptance hurdle of society, b/c soon people's fears will be overiden by the allure of genetic "screening" and "filtering" before the child is born to rid it of pre-dispositions to genetic abnormalities. After that who knows where it will go , but it seems like it will be neccessary in the future or else we will all be sickly or at least on medication and other forms of treatment and there will be no such thing as a "perfectly healthy person" * just a thought*

 

[Evadman]

DNA is made up of 4 specific "parts" aranged in certain pairs, 2 "parts" on each section. errors will be found and distroyed of the paris do not match from the original strand. but it will not catch reversals; where the 2 sets switch orentation.

These parts are called nucleotides and consist of Adenine, Guanine, Thymine, Cytosine(there are others but are less frequent) DNA consists of pairs of these bonded together(Adenine binds to thymine and Guanine binds to cytosine, hence AT-GC). If a mismatch occurs say, AC, then this will be detected and the correct base will be matched.

Hope I wasnt too long winded, and I answered your correction.

Imouthes

Thank you. Been quite a while since biology

 

[ReiAyanami]

However, evolution is implausible through simple mutations as complex organ systems require multiple simultaneous such mutations to occur all at the same time in sequence.

 

[Mark R]

However, evolution is implausible through simple mutations as complex organ systems require multiple simultaneous such mutations to occur all at the same time in sequence.

Quite. The main driving force for evolution in sexual species is the random recombination of genetic material from different individuals. Simple mutation offers relatively little drive to evolution.

Even prokaryotic organisms can use DNA exchange (essentially a primitive form of sex) to enhance the proliferation of beneficial genetic traits.

You could turn your assertion on its head, organ systems are complex because they have evolved in a step-wise fashion where each new genetic addition added a new function. There is excellent evidence for this in studies of comparative biochemistry and physiology.

 

[Shalmanese]

Wow, 13 posts before this descending into creationist rubbish, maybe the Highly Technical forums ARE inhabited by more intelligent and well-informed people .