Question

Part of a certain DNA sequence is G–G–T–C–T–A–T–A–C. What is the complementary sequence?

Short answer

The complementary DNA sequence of G–G–T–C–T–A–T–A–C is C–C–A–G–A–T–A–T–G.

Step-by-step solution

Identify the given DNA sequence

The given DNA sequence is G–G–T–C–T–A–T–A–C.

Determine the complementary bases

We know that the complementary bases are A-T and G-C pairs. So, we need to find the complementary base for each base in the given sequence: - Complementary of G (Guanine) is C (Cytosine) - Complementary of T (Thymine) is A (Adenine) - Complementary of C (Cytosine) is G (Guanine) - Complementary of A (Adenine) is T (Thymine)

Replace each base with its complementary base

Now we replace each base in the given sequence with its complementary base: - G –> C - G –> C - T –> A - C –> G - T –> A - A –> T - T –> A - A –> T - C –> G

Write the complementary sequence

After replacing each base with its complementary base, we get the complementary DNA sequence: C–C–A–G–A–T–A–T–G.

Key concepts

DNA Base Pairing

DNA base pairing is fundamental to the structure and function of DNA. Each DNA molecule consists of two strands twisted into a double helix. These strands are connected by pairs of nucleotides, the building blocks of DNA. Understanding base pairing is crucial for grasping how genetic information is stored and replicated.

In DNA, the bases pair specifically:

• Adenine (A) always pairs with Thymine (T).
• Guanine (G) always pairs with Cytosine (C).

This specificity is due to hydrogen bonding and the particular structure of the bases. The A-T pair forms two hydrogen bonds, while the G-C pair forms three, making G-C interactions slightly stronger.

Base pairing ensures that the sequence of one strand determines the sequence of its complementary strand, which is essential during DNA replication. This mechanism allows cells to duplicate their genetic material precisely, ensuring accurate transmission of genetic information.

Nucleotide Sequences

A nucleotide sequence in DNA refers to the specific order of the nucleotides, represented by the letters A, T, C, and G. Each sequence holds the information necessary for building and maintaining an organism.

DNA sequences are unique to every organism, acting like biological fingerprints. They instruct cells on how to build proteins, which are crucial for various functions and traits. The sequence you are given in the exercise, G–G–T–C–T–A–T–A–C, is one such example.

Understanding these sequences is vital because they tell us about the various genes present and their functions. Through methods like DNA sequencing, scientists can interpret these codes, allowing for insights into everything from evolutionary biology to medical research.

Genetic Code

The genetic code is a set of instructions used to translate information from a gene into proteins, which are the workhorses of the cell. Each three-nucleotide sequence, or "codon," in the DNA or RNA specifies a particular amino acid, the building blocks of proteins.

DNA sequences like the one in the exercise, G–G–T–C–T–A–T–A–C, contain this code. Each codon corresponds to an amino acid or signals a start or stop for protein synthesis.

The genetic code is universal, meaning that nearly all organisms use the same codons to specify the same amino acids. This universality underscores the shared ancestry of all life. Additionally, it allows scientists to deduce the function of genes across different organisms, facilitating advances in biotechnology, medicine, and genetic engineering. Understanding the genetic code helps us grasp how genetic instructions are translated into functional proteins that make life possible.