You have two E. coli cultures. One culture is a wild-type culture, and the other contains the lacOc mutation. But, you forgot to write labels on the tubes and have mixed them up! To help you determine which culture is which, you grow each of the cultures in growth media containing either no sugar, or just lactose. Then, you perform a beta-galactosidase assay with ONPG as your enzyme substrate. You obtain the following specific activities: Culture 1, with no sugar: 147 units Culture 1, with lactose: 158 units Culture 2, with no sugar: 3.5 units Culture 2, with lactose: 164 units Which culture contains which E. coli strain? Explain how you determined this.
Molecular Techniques
Molecular techniques are methods employed in molecular biology, genetics, biochemistry, and biophysics to manipulate and analyze nucleic acids (deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)), protein, and lipids. Techniques in molecular biology are employed to investigate the molecular basis for biological activity. These techniques are used to analyze cellular properties, structures, and chemical reactions, with a focus on how certain molecules regulate cellular reactions and growth.
DNA Fingerprinting and Gel Electrophoresis
The genetic makeup of living organisms is shown by a technique known as DNA fingerprinting. The difference is the satellite region of DNA is shown by this process. Alex Jeffreys has invented the process of DNA fingerprinting in 1985. Any biological samples such as blood, hair, saliva, semen can be used for DNA fingerprinting. DNA fingerprinting is also known as DNA profiling or molecular fingerprinting.
Molecular Markers
A known DNA sequence or gene sequence is present on a chromosome, and it is associated with a specific trait or character. It is mainly used as a genetic marker of the molecular marker. The first genetic map was done in a fruit fly, using genes as the first marker. In two categories, molecular markers are classified, classical marker and a DNA marker. A molecular marker is also known as a genetic marker.
DNA Sequencing
The most important feature of DNA (deoxyribonucleic acid) molecules are nucleotide sequences and the identification of genes and their activities. This the reason why scientists have been working to determine the sequences of pieces of DNA covered under the genomic field. The primary objective of the Human Genome Project was to determine the nucleotide sequence of the entire human nuclear genome. DNA sequencing selectively eliminates the introns leading to only exome sequencing that allows proteins coding.
You have two E. coli cultures. One culture is a wild-type culture, and the other contains the lacOc mutation. But, you forgot to write labels on the tubes and have mixed them up! To help you determine which culture is which, you grow each of the cultures in growth media containing either no sugar, or just lactose. Then, you perform a beta-galactosidase assay with ONPG as your enzyme substrate. You obtain the following specific activities:
Culture 1, with no sugar: 147 units
Culture 1, with lactose: 158 units
Culture 2, with no sugar: 3.5 units
Culture 2, with lactose: 164 units
Which culture contains which E. coli strain? Explain how you determined this.
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