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Biology
A Level

Prokaryotic DNA is smaller than eukaryotic. Please give two other ways prokaryotic DNA differs from eukaryotic.

  1. Circular2) Polycistronic (genes can be expressed together)3) No introns/no splicing of genes4) Does not form chromatin (although explain to student that this is an oversimplification, prokaryotes do...
DW
Answered by Duncan W. Biology tutor
3014 Views

Explain the lock and key enzyme hypothesis

Enzymes are specific: meaning that an enzyme's active site is complementary to a particular substrate. In the lock and key hypothesis, a substrate that is complementary to the enzyme binds to the enzyme's...

NA
Answered by Noor A. Biology tutor
6943 Views

what are three main functions of the human liver?

  1. detoxification: liver cells contain enzymes which break down toxins for example catalase, this enzyme is responsible for converting toxin hydrogen peroxide into water and oxygen. enzymes can detoxif...
MB
Answered by Megan B. Biology tutor
2999 Views

Explain the process of transcription

part of the DNA molecule unwinds DNA strands separate by DNA helicase breaking the hydrogen bonds one strand used as the template strand free nucleotides line up against DNA and bind through complementary...

MC
Answered by Molly C. Biology tutor
2751 Views

Describe and explain how the secretion of ADH affects urine production in the kidneys (4 marks)

ADH diffuses into the blood stream and binds to receptors present on the lining of the collecting duct/ DCT (1)This increases the permeability of the membrane of the collecting duct/ DCT (1)Therefore, mor...

Answered by Biology tutor
5297 Views

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