Which of the following demonstrates the central dogma of molecular biologists?
Proteins replicate DNA which gives the expression of traits to an organism.
Gene expression relies on environmental factors that determine which traits are dominant.
DNA and RNA hold the code to create proteins that are the key to gene expression.
DNA and RNA mutate into either harmful or helpful effects on the human body.
DNA and RNA hold the code to create proteins that are the key to gene expression.
The option that demonstrates the central dogma of molecular biologists is:
"DNA and RNA hold the code to create proteins that are the key to gene expression."
According to the central dogma, genetic information flows from DNA to RNA to proteins. DNA serves as the template for the synthesis of RNA, which in turn serves as the template for protein synthesis. Proteins are the molecules that carry out the majority of functions in cells and ultimately determine an organism's traits and characteristics.
The statement that demonstrates the central dogma of molecular biologists is: "DNA and RNA hold the code to create proteins that are the key to gene expression."
To understand why this statement represents the central dogma of molecular biology, we need to break it down and explain some key concepts.
1. DNA (deoxyribonucleic acid): DNA is the genetic material found in the nucleus of cells. It consists of a double helix structure made up of nucleotides. Each nucleotide is composed of a sugar molecule (deoxyribose), a phosphate group, and one of four nitrogenous bases (adenine, thymine, cytosine, and guanine). DNA serves as the blueprint for creating all the proteins that make up an organism.
2. RNA (ribonucleic acid): RNA is a single-stranded molecule that is derived from DNA. It is involved in carrying out the instructions encoded in DNA and plays a crucial role in protein synthesis.
3. Proteins: Proteins are large, complex molecules essential for the structure and function of cells and organisms. They serve various roles, including enzymes, structural components, transporters, and signaling molecules.
Now, let's explain the central dogma of molecular biology:
The central dogma of molecular biology describes the flow of genetic information within a biological system. It outlines how DNA is transcribed into RNA, which is then translated into proteins. This process is as follows:
1. DNA replication: Before a cell divides, its DNA must be accurately replicated. During replication, the DNA double helix unwinds, and each strand serves as a template for the synthesis of a new complementary strand. This results in two identical DNA molecules.
2. Transcription: The first step in gene expression is transcription. In this process, RNA is synthesized from a DNA template. The enzyme RNA polymerase binds to a specific region of DNA called the promoter, and it reads the DNA sequence and synthesizes a complementary RNA molecule. This RNA molecule is called messenger RNA (mRNA) because it carries the genetic information from DNA to the site of protein synthesis.
3. Translation: In translation, the mRNA molecule produced during transcription is used as a template to synthesize a protein. Ribosomes, the cellular machinery responsible for protein synthesis, read the mRNA sequence in groups of three nucleotides called codons. Each codon codes for a specific amino acid. Transfer RNA (tRNA) molecules bring the correct amino acids to the ribosome according to the codons on the mRNA. The ribosome links the amino acids together to form a protein.
Therefore, the statement "DNA and RNA hold the code to create proteins that are the key to gene expression" accurately represents the central dogma of molecular biology, which describes the process of gene expression through DNA transcription into RNA and subsequent translation into proteins.