10/15 Session

Which of the following statements accurately describes a key difference between the lac operon and the T7 system for gene expression in Escherichia coli?

• 1. The lac operon relies on the T7 RNA polymerase for gene transcription, while the T7 system uses lactose as an inducer.

• 1. The T7 system utilizes a native E. coli promoter, whereas the lac operon employs the T7 promoter.

• 1. Lactose is the primary inducer for the T7 system, whereas the lac operon depends on the T7 promoter for regulation.

• 1. The lac operon is a natural E. coli regulatory system for lactose metabolism, while the T7 system is an engineered system using the T7 RNA polymerase and promoter.

• 1. Both systems share a common regulatory mechanism involving the LacI repressor protein.

1. An expression vector is used to control expression of cloned genes. What must be true?

• 1. The promoter is very strong

• 1. There are multiple transcription terminators

• 1. It has efficient promoters 

• 1. The expression vector allows for high levels of protein expression

• 1. All of the above

Which of the following statements is true regarding expression vectors used in molecular biology and genetic engineering?

• 1. Expression vectors are typically used for gene sequencing and analysis.

• 1. Expression vectors contain a variety of selectable markers, but they do not carry promoter sequences.

• 1. Expression vectors are designed to facilitate the expression of foreign genes and their associated proteins.

• 1. Expression vectors are exclusively used for cloning purposes and are not involved in gene expression.

1. Place the following steps of molecular cloning in the correct order: 

1. A.Confirmation

2. B. Ligation

3. C. PCR/digestion

4. D. Transformation

• CBDA

• ABDC

• ABCD

• CDBA

1. Which of the following statements accurately describes the difference between coenzymes and prosthetic groups in enzyme function?

• 1. Coenzymes are tightly bound to the enzyme's active site, while prosthetic groups are non-covalently associated with the enzyme.

• 1. Coenzymes are small organic molecules that permanently become part of the enzyme's structure, whereas prosthetic groups are temporarily associated with the enzyme during catalysis.

• 1. Coenzymes are mostly derivatives of vitamins loosely bound to enzymes, often participating in multiple enzymatic reactions, whereas prosthetic groups are covalently bound to the enzyme and are essential for its catalytic activity.

• 1. Coenzymes and prosthetic groups are synonymous terms and can be used interchangeably.