Molecular Genetics and Protein Functions

The video discusses the one gene-one enzyme hypothesis proposed by Beadle and Tatum, which suggests that each gene codes for a specific enzyme affecting a step in a metabolic pathway. While this hypothesis was foundational, it is now considered an oversimplification. The video explains that genes can code for non-enzyme proteins, such as insulin and hemoglobin, and that proteins can be composed of multiple polypeptides coded by different genes. It also covers non-coding RNAs and their regulatory roles, as well as alternative splicing, which allows a single gene to produce multiple proteins, increasing protein diversity.

Who proposed the one gene one enzyme hypothesis?

• Watson and Crick

• Beadle and Tatum

• Franklin and Wilkins

• Mendel and Darwin

What does the one gene one enzyme hypothesis suggest?

• Enzymes are not coded by genes

• Genes do not code for enzymes

• Each gene codes for a specific enzyme

• Each gene codes for multiple enzymes

Which of the following is NOT an example of a non-enzyme protein?

• Keratin

• Hemoglobin

• Insulin

• Amylase

What is a major exception to the one gene one enzyme hypothesis?

• All proteins are enzymes

• Proteins are composed of multiple polypeptides

• Genes only code for enzymes

• Genes do not code for proteins

Which of the following proteins is composed of multiple polypeptides?

• Insulin

• Hemoglobin

• All of the above

• Keratin

What is a non-coding RNA?

• RNA that is not transcribed

• RNA that does not code for proteins

• RNA that is not involved in cellular functions

• RNA that codes for proteins

Which of the following is a type of non-coding RNA?

• Both tRNA and rRNA

• rRNA

• tRNA

• mRNA

What is alternative splicing?

• A process where one gene produces one protein

• A process where one gene can produce multiple proteins

• A process where genes are not expressed

• A process where proteins are degraded

How does alternative splicing affect protein diversity?

• It decreases protein diversity

• It has no effect on protein diversity

• It increases protein diversity

• It eliminates protein diversity

What is the significance of the one gene one enzyme hypothesis in molecular genetics?

• It has no significance

• It was a major contribution to early molecular genetics

• It is the only model used today

• It is only applicable to bacteria