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TLS Online TPP Program

#Question id: 563

Both water and glucose share an —OH that can serve as a substrate for a reaction with the terminal phosphate of ATP catalyzed by hexokinase.  Glucose, however, is about a million times more reactive as a substrate than water.  The best explanation is that:

#Unit 1. Molecules and their Interaction Relevant to Biology

  1. glucose has more —OH groups per molecule than does water.

  2. the larger glucose binds better to the enzyme; it induces a conformational change in hexokinase that brings active-site amino acids into position for catalysis.

  3. the —OH group of water is attached to an inhibitory H atom, while the glucose —OH group is attached to C.

  4. water and the second substrate, ATP, compete for the active site resulting in a competitive inhibition of the enzyme.

More Questions
TLS Online TPP Program

#Question id: 3826

#Unit 3. Fundamental Processes

Which scientists first gave experimental evidence that DNA is the genetic material?
TLS Online TPP Program

#Question id: 3827

#Unit 3. Fundamental Processes

It takes about the same amount of time for eukaryotic chromosomes to be replicated in vivo as it does for E. coli. Why is this true?
TLS Online TPP Program

#Question id: 3828

#Unit 3. Fundamental Processes

Why does E. coli need both DNA polymerase III and DNA polymerase I?
TLS Online TPP Program

#Question id: 3829

#Unit 3. Fundamental Processes

Why is only one copy of DNA made per cell division cycle in eukaryotes despite the presence of multiple origins of replication?
TLS Online TPP Program

#Question id: 3830

#Unit 3. Fundamental Processes

Why is DNA damage in skin cells from exposure to excessive UV light not completely reversed by photoreactivation?
TLS Online TPP Program

#Question id: 3831

#Unit 3. Fundamental Processes

State whether the following statements is true/false regarding DNA replication.

1. In E. coli replication begins at the origin of replication and proceeds in one direction until the entire circular DNA molecule has been copied.

2. The chromosome of the fruit fly (D. melanogaster) is about twice as large as the E. coli chromosome.

3. Prokaryotic DNA replication occurs in two steps. First, ATP provides a phosphate to the growing DNA chain. This is followed by addition of a nucleoside.

4. DNA polymerase III is the largest DNA polymerase in E. coli.

5. The β subunits of E. coli DNA polymerase form a sliding clamp that surrounds the DNA strands at the replication fork.