How are proteins synthesied from DNA?

The video above is a really good animation to help you visualise what is happening 100 trillion times per second in your body. The process can be split into two main parts; transcription and translation, which are summarised below.

Transcription:

transcription

  1. DNA-helicase unzips the DNA, exposing it.
  2. The exposed base sequence is used as a template for free RNA nucleotides. Activated RNA nucleotides (ones with 2 extra phosphoryl groups)  temporarily hydrogen bond onto the template strand of DNA (leaving the coding strand unchanged). RNA polymerase catalyses this reaction, and the extra phosphoryl groups are released, producing energy for the bonding of adjacent nucleotides.
  3. The mRNA, which is a copy of the coding strand (with T replaced by U), passes out of the nucleus, via a pore in the nuclear envelope, to a ribosome.

Translation:

translation

  1. The mRNA molecule binds with a ribosome. Two codons are attatched to the smaller subunit of the ribosome, and are therefore exposed to the larger subunit. The first codon is always AUG, and so a tRNA molecule with anticodon UAC and amino acid mathionine hydrogen bonds to the codon.
  2. A second tRNA molecule with a different amino acid and complementary anticodon binds to the second codon.
  3. The two adjacent amino acids are joined together by a peptide bond, the reaction being catalysed by an enzyme in the small ribosomal subunit.
  4. The ribosome moves along the mRNA, and a third tRNA molecule brings another amino acid, whoch forms a peptide bond with the dipeptide. The first tRNA is then released to bring another amino acid to the ribosome.
  5. The polypeptide chain continues to grow in this way until a stop codon is reached. The stop codon works because there is no tRNA for the codons UAA, UAC or UGA.
  6. The polypeptide is released and assumes its secondary and tertiary structure.
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English-German Idioms

English is ram-packed full of idiomatic phrases, and although you can on occasion translate them directly into another language, most of the time the translation will be complete nonsense! So here’s a list of 10 commonly used English idioms with their equally idiomatic German equivalents 🙂

Idiom: to be on cloud nine

Transaltion: auf Wolke sieben schweben/sich im siebenten Himmel befinden

This literally translates as to hover over cloud seven or to find oneself in the seventh sky/heaven

 

Idiom: to give someone a taste of their own medicine

Translation: es jdm. mit gleicher Münze heimzahlen

Literally this means to pay someone back with the same coin.

 

Idiom: That’ll be the day

Translation: das möchte ich einmal erleben

Possibly not as good for sarcasm as the English version, it translates as ‘I’d like to experience that one day’

Idiom: Get lost! Beat it!

Translation: Mach ‘ne Fliege!

Although there is a wide range of ways to translate this phrase, this has to be my favourite because of how absurd the direct translation sounds; ‘Do a fly!’

 

Idiom: Beggars can’t be choosers

Translation: In der Not schmeckt jedes Brot.

In my opinion the German version is much more polite, and it means ‘In adversity all bread tastes good’

Idiom: Don’t count your chickens before they’ve hatched

Translation: Man soll das Fell des Bären nicht verteilen, bevor man ihn erlegt hat.

Hunting is referenced in this saying, with the meaning being; ‘Don’t divide the bear skin before you’ve killed the bear’

Idiom: You can’t teach an old dog new tricks.

Translation: Was Hänschen nicht lernt, lernt Hans nimmermehr/Alte Bäume soll man nicht verpflanzen/ Der Mensch ist ein Gewohnheitstier.

These three phrases literally mean ‘What little Hans doesn’t learn, will old Hans never learn’, ‘Old trees shouldn’t be replanted’ and ‘Man is a creature of habit’.

 

Idiom: To be in the doghouse

Translation: der Haussegen hängt schief

This translates as ‘Domestic bliss is hanging askew’. Be careful when you use it though, as it takes bei plus the dative personal pronoun e.g. to say ‘I’m in the doghouse’ is the translation ‘Bei mir hängt der Haussegen schief’

 

Idiom: Good things come to those who wait

Translation: Geduld bringt Rosen

A sweet saying meaning ‘patience brings roses’

Idiom: the middle of nowhere

Translation: wo sich Fuchs und Hase gute Nacht sagen

Literally it means ‘where the fox and hare say good night’