Biomolecules Notes

Elements in Living Things

  • Elements that make up 95% of living organisms (by weight):
    • C = Carbon
    • H = Hydrogen
    • N = Nitrogen
    • O = Oxygen
    • P = Phosphorus
    • S = Sulfur

Carbon

  • Carbon is the building block of life and is found in all living things.
  • Carbon can form up to 4 bonds with carbon or other atoms.
  • Carbon-based molecules can form straight chains, branched chains, or rings.
  • Carbon-carbon bonds are extremely strong and stable.

Carbon-Based Molecules

  • Most of the matter in your body that is not water is made of organic compounds.
  • Organic compounds: Compounds whose molecules contain carbon and hydrogen (hydrocarbons).
  • Inorganic compounds: Compounds that do not contain carbon (e.g., CO<em>2CO<em>2, H</em>2OH</em>2O, Na+Cl−Na^+Cl^-).

Macromolecules

  • Biological molecules are typically large molecules constructed from smaller subunits.
  • Many carbon-based molecules are made of small subunits bonded together called macromolecules.

Monomers vs. Polymers

  • Biological macromolecules are large molecules made of small subunits essential for living organisms.
  • Macromolecules can also be called polymers.
  • Monomer: A small molecule that is a single subunit in a larger molecule.
    • "Mono" = One
    • "Mer" = Molecule
  • Polymers: Large molecules made of monomers (smaller molecules) bonded together.
    • "Poly" = Many
    • "Mer" = Molecule

Macromolecules of Life

  • Carbohydrates
  • Lipids (Fats)
  • Proteins
  • Nucleic Acids (DNA)

Carbohydrates (Saccharides)

  • Elements: Carbon, Hydrogen, and Oxygen atoms (1:2:1 ratio).
  • Biological functions:
    • Provide fast energy.
    • Short-term energy storage.
    • Structural support in the cell walls of plants.

Carbohydrates Structure, Function, and Examples

  • Monomer: Monosaccharide (single sugar)
  • Polymer: Polysaccharide (chain of sugars)
  • Elements: C, H, O
  • Main source of immediate energy
  • Simple sugars - fast energy
  • Complex sugars - slow energy
    • Simple Sugars - Monosaccharide: glucose
    • Disaccharide: sucrose, lactose
    • Complex sugars - Polysaccharide: starch, cellulose, glycogen

Types of Carbohydrates

  • Monosaccharide: Simple sugar (e.g., Glucose).
    • Mono- = one
  • Disaccharide: Double sugar, two monosaccharides (e.g., Sucrose).
    • Di- = two
  • Polysaccharide: Complex sugars made of 3 or more sugars.
    • Poly- = many
    • Examples:
      • Starch (plants store food as starch).
      • Glycogen (stored in the liver and muscles for quick energy).
      • Cellulose (structural support for plant).

Nutrition Facts - Carbohydrates

  • Total Carbohydrates include sugars, starches and dietary fiber.
  • Sugars are easily digested carbohydrates that provide energy but can add calories.
  • Dietary fiber is a carbohydrate that the body does not absorb. It affects how other nutrients are absorbed and digested. Cellulose is an example, found in plant cell walls.

Lipids

  • Elements: Carbon, Hydrogen, and Oxygen atoms.
  • Biological functions:
    • Nonpolar molecules (not soluble in water).
    • Insulation.
    • Waterproofing.
    • Long-term energy storage.
    • Make up the cell membrane.
  • Examples: Fats, Phospholipids, Waxes, Oils, Steroids.
  • Fats that are liquid at room temperature are called oils.

Lipids Structure, Function, and Examples

  • Monomer: Fatty acid + glycerol
  • Polymer: Lipid molecule
  • Elements: C, H, O
    1. Energy storage
    2. Insulation
    3. Cell structure (membrane/waterproof)
    4. Some Hormones
  • Phospholipids
  • Wax
  • Steroids

Saturated or Unsaturated

  • Usually solid
  • Unhealthy
  • Ex. butter
  • Usually liquid
  • Healthier
  • Ex. olive oil

Fatty Acids

  • Fatty Acids: chains of carbon atoms bonded to hydrogen atoms
  • Saturated: contain the maximum number of hydrogen atoms (all bonds between carbon are single bonds).
  • Unsaturated: contain fewer hydrogen atoms due to the presence of double bonds between carbon atoms.

Nutrition Facts - Lipids

  • Fats can be classified as saturated or unsaturated. Limiting dietary fat intake is generally recommended.
  • Saturated fats consist of carbon atom chains with single bonds and the maximum number of hydrogen atoms. Experts recommend limiting them due to potential links to heart disease and diabetes.
  • Unsaturated fats do not have the maximum number of hydrogens. Cis fats are more common in natural sources, while trans fats are more common in highly processed foods. Diets heavy in trans fats can increase the risk of heart disease.
  • Cholesterol is necessary for health, but a diet high in cholesterol can lead to heart disease, and limiting intake is recommended.

Proteins

  • Elements: Carbon, Hydrogen, Oxygen, Nitrogen (some have Sulfur).
  • Biological functions:
    • Catalyze chemical reactions (enzymes).
    • Structural support.
    • Transport molecules in cells.
    • Protective molecules of cells.
  • Examples: Enzymes, Collagen, Keratin, Hemoglobin (blood), Antibodies.

Protein Diversity

  • Proteins are the most diverse group with many structures.
  • The structure of a protein greatly influences its function.
  • The building blocks of proteins are called amino acids. There are 20 amino acids.

Protein - Amino Acids

  • Different sequences of amino acids result in different proteins being made.
  • Proteins' main function is to build structure and carry out all metabolism.
  • Some functions of proteins:
    • Structural (hair and nails).
    • Function in transport (hemoglobin).
    • Function in movement (muscle fibers and cytoskeletal elements).
    • Defense (antibodies).
    • Regulation of cell functions (hormones and enzymes).

Proteins Structure, Function, and Examples

  • Monomer: Amino acids (20 total, 12 made by the body).
  • Polymer: Protein/polypeptide chain (formed by peptide/covalent bonds).
  • Elements: C, O, H, N
    1. Controlling the rate of reactions (enzymes).
    2. Regulating cell processes.
    3. Forming bones and muscles.
    4. Transporting substances into cells.
    5. Helping to fight diseases (antibodies).
  • Insulin- breaks down sugar in blood
  • Keratin- hair and nails
  • Melanin- skin/hair color
  • Enzymes- speed up chemical reactions
    • Amylase- in saliva
    • Lactase- break down lactose in milk
    • Pepsin- stomach
  • Hemoglobin- allows RBC to carry oxygen

Nutrition Facts - Protein

  • Percent daily value is often not listed, unless the food claims to be high in protein or is made for young children.
  • The percent is based on a 2,000 Calorie diet.
  • Protein you eat is used as fuel and to build hormones, enzymes, and body tissues. Proteins are not broken out into subgroups on the nutrition label.

Nucleic Acids

  • Elements: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus.
  • Biological function:
    • Store genetic information.
    • Direct the synthesis of proteins.
  • Examples:
    • DNA (2 Strands)
    • RNA (1 Strand)

Nucleic Acids and Nucleotides

  • Nucleic acids are large, complex macromolecules that store information in the form of a code.
  • Nucleic acids are made up of nucleotides (sugar, base, phosphate group).

Nucleic Acids - Examples

  • Deoxyribonucleic Acid (DNA) - genetic code that passes instructions from parents to offspring.
  • Ribonucleic Acid (RNA) - copy and transfer genetic information in a cell to make proteins.

Nucleic Acids Structure, Function, and Example

  • Monomer: Nucleotide
  • Polymer: Nucleic acid (DNA or RNA)
  • Elements: C, O, H, N, and P
  • Stores and transmits genetic information
  • DNA: stores genetic information
  • RNA: helps in making proteins.

Summary of Macromolecules

  • Carbohydrates
    • Monomer: Sugar
    • Functions: Store energy, structural material
    • Examples: Potato
  • Lipids
    • Monomer: Fatty acid
    • Functions: Store energy, form membranes
    • Examples: Steroids, fat cells
  • Proteins
    • Monomer: Amino Acid
    • Functions: Enzymes, structural material
    • Examples: Peptides, hair
  • Nucleic Acids
    • Monomer: Nucleotide
    • Functions: Store genetic information
    • Examples: DNA