Biochemical Pathways and Complementation

Question 1

What is a biochemical pathway?

Answer 1

A series of steps involving several intermediate product being transformed into other things by enzymes until the end product necessary for life is created

Question 2

How can a prototrophic strain be distinguished from an auxotrophic strain?

Answer 2

Prototrophs will grow on minimal media, but auxotrophs won’t

Question 3

Why are auxotrophs unable to grow on minimal media?

Answer 3

They have a blockage in a pathway that prevents them from making some essential end product. Without the end product, they can’t grow

Question 4

How can an auxotrophic strain be rescued?

Answer 4

By adding an intermediate product downstream of the blockage or by adding the end product

Question 5

What did Beadle and Tatum’s experiment demonstrate about biochemical pathways?

Answer 5

A mutation in a single gene disrupts the function of a single enzyme, so one gene, one enzyme

Question 6

What is complementation?

Answer 6

The restoration of wild type phenotype when two haploid mutants are crossed

Question 7

What is the difference between allelic and non-allelic mutations?

Answer 7

Allelic mutations are on the same gene, non-allelic mutations are on different genes

Question 8

What does a complementation test tell us?

Answer 8

If two auxotrophic strains with the same mutant phenotype have allelic or non-allelic mutations