4a. Missense mutation occurs in DNA segment of E. coli and causes changes of lacZ gene in lac operon. Explain the mechanism of lac operon in the presence of lactose for this mutated E. coli

1. environmental factors, such as ph and temperature, can affect the function of an enzyme. a. true b. false 2. which of the following is an organic molecules (ex. vitamins) that an enzyme? a. coenzyme b. product c. active site d. substrate 3. how do enzymes effect the speed of a chemical reaction? a. they speed it up b. they slow it down c. they have no effect on the speed of a reaction 4. during a chemical reaction, an enzyme is used up so that it can only be used one time. a. true b. false 5. which of the following results from a chemical reaction that is catalyzed by an enzymes? a. active site b. product c. substrate d. coenzyme

If the coding part of an mrna molecule is 1800 nucleotides (bases) in length, this molecule will contain codons and code for a polypeptide that is amino acids long.

The green colored pigment in chloroplasts is? a. nitrogen b. chlorophyll c. chlorophorm d. chlorofloromethane