DNA

Definition

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms, carrying the genetic instructions for the development, functioning, growth, and reproduction of living things. Its structure, a double helix formed by nucleotide chains, allows it to store vast amounts of information necessary for cellular processes, linking it to various biological functions.

5 Must Know Facts For Your Next Test

1. DNA is composed of two strands that coil around each other to form a double helix, with each strand made up of nucleotides linked together by chemical bonds.
2. The sequence of the nitrogenous bases in DNA determines the genetic information carried by the molecule, essentially acting as a code for building proteins.
3. DNA replication is essential for cell division, ensuring that each new cell receives an exact copy of the genetic material.
4. Mutations in DNA can lead to changes in protein synthesis and may result in various diseases or disorders.
5. In addition to its role in heredity, DNA is involved in regulating cellular processes through mechanisms like gene expression.

Review Questions

• How does the structure of DNA facilitate its function in storing and transmitting genetic information?
  • The structure of DNA as a double helix allows it to pack a large amount of genetic information into a compact space while maintaining stability. The specific pairing of nitrogenous bases (adenine with thymine and cytosine with guanine) enables accurate replication during cell division, ensuring that genetic information is passed on correctly. Additionally, the sequence of these bases codes for proteins, making it essential for the functioning and development of organisms.
• Discuss the process of DNA replication and its importance in cell division.
  • DNA replication is a semi-conservative process where each strand of the original DNA molecule serves as a template for the creation of a new complementary strand. This ensures that when cells divide, each daughter cell receives an identical set of genetic instructions. Enzymes like DNA polymerase play crucial roles in adding nucleotides to form new strands. Accurate replication is vital because errors can lead to mutations that may disrupt normal cellular function.
• Evaluate the implications of DNA mutations on protein synthesis and overall human health.
  • DNA mutations can have significant implications for protein synthesis, potentially leading to dysfunctional proteins that can disrupt normal physiological processes. For instance, a mutation in a gene can result in a change in the amino acid sequence of a protein, which may impair its function or render it inactive. This can contribute to various health issues, including genetic disorders like cystic fibrosis or cancer. Understanding these mutations is crucial for developing targeted therapies and improving health outcomes.

Related terms

Nucleotide: The basic building block of DNA, consisting of a sugar, phosphate group, and nitrogenous base.

Gene:

A segment of DNA that contains the instructions for making a specific protein or set of proteins.

Chromosome:

A structure made of DNA and proteins that contains many genes and is found in the nucleus of eukaryotic cells.