Question

Nitrogen would be found in which categories of molecules unique to organisms? (page 28 )

Short answer

Nitrogen is found in two categories of molecules unique to organisms: proteins and nucleic acids. Proteins contain nitrogen due to the presence of amino acids, while nucleic acids, like DNA and RNA, contain nitrogen in their nucleotide's nitrogenous bases.

Step-by-step solution

Recall the major types of biological macromolecules

There are four main categories of biological macromolecules found in living organisms: carbohydrates, lipids, proteins, and nucleic acids.

Identify the categories containing nitrogen

Now, we examine each category to determine which ones have nitrogen in their structure: 1. Carbohydrates: These are composed of carbon, hydrogen, and oxygen atoms. They don't contain nitrogen. 2. Lipids: These are composed mainly of carbon and hydrogen atoms, with some lipids possessing oxygen and phosphorus. Generally, lipids do not contain nitrogen. 3. Proteins: Proteins are composed of amino acids, which contain carbon, hydrogen, oxygen, and nitrogen. Therefore, proteins contain nitrogen. 4. Nucleic acids: These are composed of nucleotides, which contain nitrogenous bases. Nucleic acids, such as DNA and RNA, contain nitrogen in their structure.

Summarize the answer

Based on the analysis, nitrogen can be found in two categories of molecules unique to organisms: proteins and nucleic acids.

Key concepts

Proteins

Proteins are complex molecules that play many critical roles in biological systems. They are involved in virtually every cellular process. Made up of long chains of amino acids, proteins are essential components of all living organisms. The building blocks of proteins, amino acids, include an amino group that contains nitrogen, which is vital for forming the peptide bonds between amino acids.

• Proteins act as enzymes, speeding up chemical reactions.
• They serve as antibodies, defending the body against foreign invaders.
• Proteins help in the transport and storage of molecules. For instance, hemoglobin transports oxygen in the blood.
• They play an important role in cellular structure and support.

The presence of nitrogen is fundamental to protein structure, making it one of the primary nitrogen-containing macromolecules in organisms.

Nucleic Acids

Nucleic acids are macromolecules that store and transfer genetic information in cells. Two primary types of nucleic acids are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). They are composed of nucleotides, which include nitrogenous bases such as adenine, thymine (in DNA), cytosine, and guanine, and RNA incorporates uracil instead of thymine.

These nitrogenous bases are crucial for the encoding, transmission, and expression of genetic information. DNA holds the instructions for building proteins, while RNA translates and carries these instructions to the cellular machinery.

• DNA is double-stranded and contains the genetic blueprint for inheritance.
• RNA is usually single-stranded and plays a role in protein synthesis.

The nitrogen present in these bases is essential for the unique structure and function of nucleic acids.

Biological Macromolecules

Biological macromolecules are large, complex molecules that are essential for life. They include four main categories: proteins, nucleic acids, carbohydrates, and lipids. These molecules form the foundation of living organisms’ structures and are involved in all life processes.

Nitrogen is a key component of proteins and nucleic acids, impacting their structural and functional properties significantly. While carbohydrates and most lipids do not typically contain nitrogen, proteins and nucleic acids are rich in this element, highlighting their pivotal roles in biological functions.

• Macromolecules are formed by processes of polymerization where monomers join to create larger structures.
• They play roles ranging from structural components to energy storage and information transfer.
• Understanding these components helps in grasping how biological systems operate and maintain life.

Recognizing the nitrogen-containing macromolecules allows us to appreciate their importance in biological systems.

Amino Acids

Amino acids are the basic building blocks of proteins. There are 20 different amino acids that combine in various sequences to form a vast array of proteins, each with unique functions. Amino acids contain an amino group ( -NH2 ) that includes nitrogen, which is crucial to their structure.

Each amino acid has a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable "R" group or side chain.

• The "R" group determines the properties and function of the amino acid.
• Amino acids are linked by peptide bonds in proteins, which form between the amino group of one and the carboxyl group of another.
• The sequence and number of amino acids in a protein are what give it its specific functions.

Nitrogen's presence in amino acids is indispensable for the synthesis and function of proteins, supporting life at molecular levels.

Nucleotides

Nucleotides are the individual building blocks of nucleic acids like DNA and RNA. They consist of three components: a nitrogenous base, a five-carbon sugar, and one or more phosphate groups. The nitrogenous bases in nucleotides can be adenine, thymine (only in DNA), cytosine, guanine, and uracil (only in RNA).

These bases are key to the function of nucleic acids as they form specific pairing patterns that enable the storage and transmission of genetic information.

• Each nucleotide is made up of one of five nitrogenous bases.
• The sequence of nitrogenous bases encodes genetic information.
• In DNA, nucleotides form a double helix structure, while RNA is typically single-stranded.

The nitrogen in nucleotides is essential for the stability and functionality of genetic materials, underscoring its role in heredity and cellular regulation.