Biomolecules: Proteins and Nucleic Acids

Definition: Large, complex molecules made up of amino acids.
Functions:
- Catalysis (enzymes)
- Structural support (collagen, keratin)
- Transport (hemoglobin)
- Defense (antibodies)
- Signaling (hormones)
Structure:
- Primary: Sequence of amino acids
- Secondary: Alpha helices and beta sheets
- Tertiary: 3D folding of a polypeptide
- Quaternary: Multiple polypeptide chains interacting
Types:
- Enzymes
- Structural proteins
- Transport proteins
- Antibodies
- Signaling proteins

Definition: Polymers made of nucleotide monomers; essential for storing and transmitting genetic information.
Types:
- DNA (Deoxyribonucleic Acid)
  - Double helix structure
  - Stores genetic information
  - Bases: Adenine (A), Thymine (T), Cytosine (C), Guanine (G)
- RNA (Ribonucleic Acid)
  - Single-stranded
  - Involved in protein synthesis
  - Bases: Adenine (A), Uracil (U), Cytosine (C), Guanine (G)
Functions:
- Genetic coding (DNA)
- Protein synthesis (mRNA, tRNA, rRNA)
- Regulation of gene expression

Definition: Hydrophobic or amphipathic molecules, primarily composed of hydrocarbons.
Types:
- Fats (triglycerides)
  - Glycerol + 3 fatty acids
  - Energy storage, insulation
- Phospholipids
  - Glycerol + 2 fatty acids + phosphate group
  - Major component of cell membranes
- Steroids
  - Four fused carbon rings (cholesterol)
  - Hormonal functions and membrane fluidity
Functions:
- Energy storage
- Cellular structure (membranes)
- Signaling molecules (hormones)

Definition: Organic compounds made of carbon, hydrogen, and oxygen; serve as energy sources and structural components.
Types:
- Monosaccharides
  - Simple sugars (e.g., glucose, fructose)
- Disaccharides
  - Two monosaccharides linked (e.g., sucrose, lactose)
- Oligosaccharides
  - Short chains of monosaccharides
- Polysaccharides
  - Long chains (e.g., starch, glycogen, cellulose)
Functions:
- Energy storage (starch in plants, glycogen in animals)
- Structural role (cellulose in plants)
- Cell recognition (glycoproteins, glycolipids)

Large, complex molecules composed of amino acids with diverse functions.
Functions include catalysis (enzymes), structural support (collagen, keratin), transport (hemoglobin), defense (antibodies), and signaling (hormones).
Protein structure is organized in four levels:
- Primary: linear sequence of amino acids.
- Secondary: formation of alpha helices and beta sheets.
- Tertiary: 3D conformation of a single polypeptide chain.
- Quaternary: interaction of multiple polypeptide chains.
Five main types include enzymes, structural proteins, transport proteins, antibodies, and signaling proteins.

Polymers of nucleotides crucial for genetic information storage and transfer.
Two primary types are DNA and RNA:
- DNA: double helix structure that holds genetic information; bases include adenine (A), thymine (T), cytosine (C), and guanine (G).
- RNA: single-stranded, involved in protein synthesis; bases include adenine (A), uracil (U), cytosine (C), and guanine (G).
Functions include genetic coding (DNA) and various roles in protein synthesis (mRNA, tRNA, rRNA) and gene expression regulation.

Hydrophobic or amphipathic molecules largely constructed from hydrocarbons.
Types of lipids include:
- Fats (triglycerides): composed of glycerol and three fatty acids, serving as energy storage and insulation.
- Phospholipids: consist of glycerol, two fatty acids, and a phosphate group, forming the fundamental structure of cell membranes.
- Steroids: defined by four fused carbon rings (e.g., cholesterol), essential for hormonal regulation and membrane fluidity.
Key functions encompass energy storage, cellular structural roles (membranes), and signaling (hormonal).

Organic compounds featuring carbon, hydrogen, and oxygen, primarily serving as energy sources and structural elements.
Types include:
- Monosaccharides: simple sugars, such as glucose and fructose.
- Disaccharides: composed of two monosaccharides linked, e.g., sucrose and lactose.
- Oligosaccharides: short chains of monosaccharides.
- Polysaccharides: lengthy chains like starch, glycogen, and cellulose.
Functions are diverse, covering energy storage (starch in plants, glycogen in animals), structural roles (cellulose in plants), and facilitating cell recognition (glycoproteins, glycolipids).

Polarity: Water exhibits polarity, with a partial negative charge on oxygen and partial positives on hydrogens, creating strong hydrogen bonds between molecules.
Cohesion: The strong attraction between water molecules results in surface tension, allowing small objects, like insects, to float on water.
Adhesion: Water's ability to adhere to other substances contributes to capillary action, enabling plants to draw water from soil through their roots.
High Specific Heat: Water can absorb significant heat without a large temperature increase, playing a vital role in climate regulation and maintaining stable body temperatures in organisms.
High Heat of Vaporization: Converting water from liquid to gas requires substantial energy, making processes like sweating effective for cooling organisms.
Density: Ice has a lower density than liquid water, allowing it to float; this property insulates water bodies, helping aquatic life survive in cold conditions.
Universal Solvent: Water's polarity allows it to dissolve various substances, facilitating important chemical reactions in biological systems.

Dissolution of Ionic Compounds: Water's polar molecules interact with ionic compounds, such as table salt, separating and surrounding the individual ions and leading to their dissolution.
Dissolution of Polar Molecules: Water can also dissolve polar substances, like sugars, through hydrogen bonding, enhancing their mobility in solutions.
Biological Importance: Aqueous solutions are essential for biochemical reactions; water serves as a medium for nutrient transport and waste removal in cells.
Role in Metabolism: Water is crucial in metabolic reactions, participating in hydrolysis (breaking down molecules) and dehydration synthesis (building larger molecules) processes.
Concentration and Dilution: Water is frequently used to dilute chemical solutions, which influences reaction rates and the equilibrium state of reactions.