Nitrogen Containing Organic Compounds

SOME CARBON-NITROGEN COMPOUNDS OF BIOLOGICAL IMPORTANCE

• Nitrogen-containing organic compounds play crucial roles in biological processes
• These compounds are essential for the structure and function of living organisms
• Some important carbon-nitrogen compounds include:
• Amino acids
• Proteins
• Nucleic acids
• Enzymes
• Hormones
• Let’s explore each of these compounds in detail.

Amino Acids

• Amino acids are the building blocks of proteins
• They contain a carboxyl group (-COOH) and an amino group (-NH2) attached to the same carbon atom
• There are 20 naturally occurring amino acids
• Examples of amino acids include alanine, glycine, and valine
• Amino acids can act as acids or bases depending on the pH of the solution

Proteins

• Proteins are large, complex molecules made up of amino acids
• They have various functions in the body, including structural support, enzymatic activity, and transportation of molecules
• The primary structure of a protein is determined by the sequence of amino acids
• Examples of proteins include hemoglobin, insulin, and collagen
• Proteins fold into a specific three-dimensional structure to carry out their functions

Nucleic Acids

• Nucleic acids are macromolecules that store and transmit genetic information
• There are two types of nucleic acids: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)
• Nucleic acids are composed of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base
• Examples of nucleic acids include DNA, RNA, and ATP (adenosine triphosphate)
• Nucleic acids play a crucial role in protein synthesis and inheritance of traits

Enzymes

• Enzymes are biological catalysts that speed up chemical reactions in living organisms
• They are made up of proteins and often require cofactors or coenzymes to function properly
• Enzymes are highly specific and can catalyze a wide range of reactions
• Examples of enzymes include amylase, pepsin, and DNA polymerase
• Enzymes play a vital role in metabolism, digestion, and regulation of cellular processes

Hormones

• Hormones are chemical messengers that regulate various physiological processes in the body
• They are produced by endocrine glands and travel through the bloodstream to target cells
• Hormones can be proteins, peptides, or steroid derivatives
• Examples of hormones include insulin, thyroxine, and adrenaline
• Hormones control growth, metabolism, reproduction, and other important functions in the body

Summary

• Carbon-nitrogen compounds of biological importance are essential for living organisms
• Amino acids are the building blocks of proteins
• Proteins have various functions and fold into a specific structure
• Nucleic acids store and transmit genetic information
• Enzymes are biological catalysts that speed up chemical reactions
• Hormones are chemical messengers that regulate physiological processes
• Understanding these compounds is essential in studying the chemistry of life.

Amino Acids - Structure and Classification

• Amino acids contain an amino group (-NH2) and a carboxyl group (-COOH)
• The central carbon atom is called the alpha carbon
• The side chain (R group) determines the properties of the amino acid
• Amino acids can be classified as:
  • Nonpolar (hydrophobic)
  • Polar (hydrophilic)
  • Charged (acidic or basic)

Nonpolar Amino Acids

• Nonpolar amino acids have hydrophobic side chains
• Examples include alanine, glycine, and valine
• These amino acids tend to cluster together in the interior of proteins
• They do not readily interact with water

Polar Amino Acids

• Polar amino acids have hydrophilic side chains
• Examples include serine, cysteine, and glutamine
• These amino acids readily interact with water
• They can form hydrogen bonds with other polar molecules

Charged Amino Acids: Acidic

• Acidic amino acids have a negatively charged side chain at physiological pH
• Examples include aspartic acid and glutamic acid
• The side chain can dissociate to release a hydrogen ion (H+)
• These amino acids are negatively charged in solution

Charged Amino Acids: Basic

• Basic amino acids have a positively charged side chain at physiological pH
• Examples include lysine, arginine, and histidine
• The side chain can accept a hydrogen ion (H+)
• These amino acids are positively charged in solution

Proteins - Structure and Functions

• Proteins are polymers of amino acids linked by peptide bonds
• The primary structure is the sequence of amino acids
• The secondary structure is the local folding of the polypeptide chain
• The tertiary structure is the three-dimensional conformation of the protein
• The quaternary structure is the arrangement of multiple protein subunits

Primary Structure of Proteins

• The primary structure is determined by the sequence of amino acids
• Each amino acid is linked to the next by a peptide bond
• The sequence of amino acids is encoded in the DNA

Secondary Structure of Proteins

• The secondary structure refers to the local folding patterns of the polypeptide chain
• Two common secondary structures are:
  • Alpha helix: The polypeptide chain forms a helical structure
  • Beta sheet: The polypeptide chain forms an extended zigzag structure

Tertiary Structure of Proteins

• The tertiary structure is the overall three-dimensional conformation of the protein
• It is determined by interactions between amino acid side chains
• Interactions include hydrogen bonding, hydrophobic interactions, and disulfide bonds

Quaternary Structure of Proteins

• Some proteins consist of multiple subunits
• The quaternary structure refers to the arrangement of these subunits
• Interactions between subunits stabilize the overall protein structure

Nucleic Acids - DNA (Deoxyribonucleic Acid)

• DNA is a double-stranded nucleic acid that stores genetic information
• It consists of nucleotides, which are composed of a sugar (deoxyribose), a phosphate group, and a nitrogenous base
• There are four nitrogenous bases in DNA:
  • Adenine (A) pairs with thymine (T)
  • Guanine (G) pairs with cytosine (C)
• The pairing of bases forms the double helix structure of DNA

Nucleic Acids - RNA (Ribonucleic Acid)

• RNA is a single-stranded nucleic acid that is involved in protein synthesis
• It also consists of nucleotides with a sugar (ribose), a phosphate group, and a nitrogenous base
• There are four nitrogenous bases in RNA:
  • Adenine (A) pairs with uracil (U)
  • Guanine (G) pairs with cytosine (C)
• RNA plays a crucial role in the translation of genetic information from DNA to protein

Nucleic Acids - ATP (Adenosine Triphosphate)

• ATP is a nucleotide that functions as an energy carrier in cells
• It consists of adenosine (adenine + ribose) and three phosphate groups
• The high-energy bonds between the phosphate groups store and release energy
• ATP is involved in various cellular processes such as muscle contraction and active transport

Enzymes - Properties and Mechanism

• Enzymes are highly specific catalysts that increase the rate of chemical reactions
• They lower the activation energy required for a reaction to occur
• Enzymes are not consumed in the reaction and can be reused
• Enzymes are specific to a particular substrate, and the active site binds to the substrate
• Enzymes can undergo conformational changes to promote the reaction

Enzyme Substrate Complex

• The enzyme binds to the substrate, forming an enzyme-substrate complex
• The active site of the enzyme is complementary to the substrate
• The binding of the substrate to the active site allows for specific interactions
• These interactions facilitate the conversion of the substrate to the product

Factors Affecting Enzyme Activity

• Enzyme activity can be influenced by several factors, including:
  • Temperature: Enzymes have an optimum temperature for activity
  • pH: Enzymes have an optimum pH for activity
  • Substrate concentration: Increasing substrate concentration can increase enzyme activity, up to a point of saturation
  • Enzyme concentration: Increasing enzyme concentration can increase the rate of reaction

Enzyme Inhibition

• Enzyme activity can be inhibited by certain molecules or factors
• Competitive inhibition occurs when a molecule competes with the substrate for the active site
• Non-competitive inhibition occurs when a molecule binds to a site other than the active site, altering the enzyme’s conformation

Hormones - Types and Functions

• Hormones are chemical messengers that regulate various physiological processes
• There are different types of hormones:
  • Peptide hormones: Made up of amino acids, examples include insulin and glucagon
  • Steroid hormones: Derived from cholesterol, examples include estrogen and testosterone
  • Amine hormones: Derived from amino acids, examples include adrenaline and melatonin

Hormonal Regulation

• Hormones regulate processes such as growth, metabolism, reproduction, and stress response
• They are secreted by endocrine glands and travel through the bloodstream to target cells or organs
• Hormones can have both short-term and long-term effects on the body
• Hormonal imbalances can lead to various disorders and diseases

Feedback Mechanism in Hormonal Regulation

• Hormonal regulation often involves a feedback mechanism
• Negative feedback: The response to a stimulus inhibits further hormone release
• Positive feedback: The response to a stimulus enhances further hormone release
• Feedback mechanisms help maintain homeostasis and regulate hormone levels