Chapter 15: Genes and How They Work
© 2020 McGraw-Hill Education. 15-1
, The Nature of Genes
Early ideas to explain how genes work came from
studying human diseases
Archibald Garrod – 1902
• Recognized that alkaptonuria is inherited via a
recessive allele.
• Proposed that patients with the disease lacked a
particular enzyme.
These ideas connected genes to enzymes
© 2020 McGraw-Hill Education. 15-2
,The central dogma describes information
flow
First described by Francis Crick
Information only flows from
DNA → RNA → protein
Transcription = DNA → RNA
Translation = RNA → protein
Retroviruses violate this order using reverse
transcriptase to convert their RNA genome into DNA
© 2020 McGraw-Hill Education. 15-3
, Replication
DNA
Reverse
Transcription
transcription
Translation
RNA Protein
© 2020 McGraw-Hill Education. 15-4
© 2020 McGraw-Hill Education. 15-1
, The Nature of Genes
Early ideas to explain how genes work came from
studying human diseases
Archibald Garrod – 1902
• Recognized that alkaptonuria is inherited via a
recessive allele.
• Proposed that patients with the disease lacked a
particular enzyme.
These ideas connected genes to enzymes
© 2020 McGraw-Hill Education. 15-2
,The central dogma describes information
flow
First described by Francis Crick
Information only flows from
DNA → RNA → protein
Transcription = DNA → RNA
Translation = RNA → protein
Retroviruses violate this order using reverse
transcriptase to convert their RNA genome into DNA
© 2020 McGraw-Hill Education. 15-3
, Replication
DNA
Reverse
Transcription
transcription
Translation
RNA Protein
© 2020 McGraw-Hill Education. 15-4
