Dna is made of repeating units called

General
1

dna is made of repeating units called

2

LectureNotes said DNA is made of repeating units called…

Answer: DNA (Deoxyribonucleic Acid) is composed of repeating units called nucleotides. Each nucleotide consists of three main components:

  1. A phosphate group
  2. A five-carbon sugar (deoxyribose in the case of DNA)
  3. A nitrogenous base (which can be adenine, thymine, cytosine, or guanine)

Structure of a Nucleotide

  1. Phosphate Group:

    • The phosphate group is a phosphorus atom bonded to four oxygen atoms. It forms part of the backbone of the DNA structure.

  2. Five-Carbon Sugar (Deoxyribose):

    • Deoxyribose is a five-carbon sugar molecule lacking one oxygen atom compared to ribose, which is the sugar found in RNA. The deoxyribose in each nucleotide connects to the phosphate group of the next nucleotide, forming a sugar-phosphate backbone.

  3. Nitrogenous Bases:

    • There are four types of nitrogenous bases in DNA:
      • Adenine (A)
      • Thymine (T)
      • Cytosine (C)
      • Guanine (G)

DNA Structure:

DNA forms a double helix structure, where the two strands run in opposite directions (antiparallel). The nitrogenous bases from each strand pair up with complementary bases from the other strand, forming hydrogen bonds:

  • Adenine pairs with Thymine (A-T) via two hydrogen bonds.
  • Cytosine pairs with Guanine (C-G) via three hydrogen bonds.

Importance of Nucleotides:

  • Genetic Information: Nucleotides serve as the building blocks for DNA, which stores and transmits genetic information in living organisms.
  • Replication: During cell division, DNA can replicate because each strand serves as a template for a new complementary strand, ensuring that genetic information is consistently passed on.
  • Protein Synthesis: DNA encodes the instructions for synthesizing proteins, which are crucial for virtually every function within a cell.

Understanding that DNA is made of repeating units called nucleotides is fundamental to the study of genetics and molecular biology.