Biomolecules: Carbohydrates and Proteins

Biomolecules

• Carbohydrates: Provide energy for cells, composed of carbon, hydrogen, and oxygen (CHO)
  • Monosaccharides (e.g. glucose, fructose)
  • Disaccharides (e.g. sucrose, lactose)
  • Polysaccharides (e.g. starch, cellulose)
• Proteins: Perform structural, enzymatic, and transport functions, composed of amino acids
  • 20 standard amino acids, classified into essential and non-essential
  • Primary structure (sequence of amino acids)
  • Secondary structure (alpha helix, beta sheet)
  • Tertiary structure (3D shape)
  • Quaternary structure (protein-protein interactions)
• Lipids: Energy storage, composed of carbon, hydrogen, and oxygen (CHO)
  • Triglycerides (fats and oils)
  • Phospholipids (cell membranes)
  • Steroids (hormones, cholesterol)
• Nucleic Acids: Store genetic information, composed of nucleotides
  • DNA (deoxyribonucleic acid)
  • RNA (ribonucleic acid)

Metabolic Pathways

• Glycolysis: Breakdown of glucose to pyruvate, producing ATP and NADH
• Citric Acid Cycle: Breakdown of acetyl-CoA to CO2, producing ATP, NADH, and FADH2
• Fatty Acid Oxidation: Breakdown of fatty acids to acetyl-CoA, producing ATP and NADH
• Electron Transport Chain: Generation of ATP from NADH and FADH2
• Protein Synthesis: Translation of mRNA into a polypeptide chain

Enzymes

• Catalysts: Increase reaction rates without being consumed
• Substrate: Molecule that binds to an enzyme
• Active Site: Region of the enzyme where substrate binds
• Enzyme Inhibition: Reduction of enzyme activity
  • Competitive inhibition (substrate binding site)
  • Non-competitive inhibition (allosteric site)

Cellular Signaling

• Hormones: Chemical messengers that transmit signals between cells
• Receptors: Proteins that bind to hormones or signaling molecules
• Signal Transduction: Pathway of molecular interactions that transmit signals
• Second Messengers: Molecules that amplify signals (e.g. cAMP, IP3)

Laboratory Techniques

• Chromatography: Separation of molecules based on properties (e.g. size, charge)
• Electrophoresis: Separation of charged molecules based on size and charge
• Spectroscopy: Analysis of molecular structure using electromagnetic radiation
  • UV-Vis spectroscopy
  • Infrared spectroscopy
  • NMR spectroscopy

Biomolecules

• Carbohydrates: Provide energy for cells, composed of carbon, hydrogen, and oxygen (CHO)
  • Monosaccharides are simple sugars, e.g. glucose, fructose
  • Disaccharides are formed by linking two monosaccharides, e.g. sucrose, lactose
  • Polysaccharides are complex carbohydrates, e.g. starch, cellulose
• Proteins: Perform structural, enzymatic, and transport functions, composed of amino acids
  • There are 20 standard amino acids, classified into essential and non-essential
  • Primary structure is the sequence of amino acids in a protein
  • Secondary structure includes alpha helix and beta sheet formations
  • Tertiary structure is the 3D shape of a protein
  • Quaternary structure involves protein-protein interactions
• Lipids: Energy storage, composed of carbon, hydrogen, and oxygen (CHO)
  • Triglycerides are fats and oils, composed of glycerol and fatty acids
  • Phospholipids are major components of cell membranes
  • Steroids are lipids that include hormones and cholesterol
• Nucleic Acids: Store genetic information, composed of nucleotides
  • DNA (deoxyribonucleic acid) is a double-stranded molecule
  • RNA (ribonucleic acid) is a single-stranded molecule

Metabolic Pathways

• Glycolysis: Breakdown of glucose to pyruvate, producing ATP and NADH
  • Occurs in the cytosol of cells
  • Produces 2 ATP and 2 NADH molecules
• Citric Acid Cycle: Breakdown of acetyl-CoA to CO2, producing ATP, NADH, and FADH2
  • Occurs in the mitochondria
  • Produces 2 ATP, 6 NADH, and 2 FADH2 molecules
• Fatty Acid Oxidation: Breakdown of fatty acids to acetyl-CoA, producing ATP and NADH
  • Occurs in the mitochondria
  • Produces ATP and NADH molecules
• Electron Transport Chain: Generation of ATP from NADH and FADH2
  • Occurs in the mitochondria
  • Produces ATP molecules
• Protein Synthesis: Translation of mRNA into a polypeptide chain
  • Occurs in the ribosomes
  • Requires amino acids, mRNA, and ribosomes

Enzymes

• Catalysts: Increase reaction rates without being consumed
  • Lower the activation energy of a reaction
  • Remain unchanged after the reaction
• Substrate: Molecule that binds to an enzyme
  • Fits into the active site of the enzyme
  • Is converted into a product
• Active Site: Region of the enzyme where substrate binds
  • Has a specific shape and charge
  • Determines the enzyme's specificity
• Enzyme Inhibition: Reduction of enzyme activity
  • Competitive inhibition: substrate binds to active site, blocking the enzyme
  • Non-competitive inhibition: inhibitor binds to allosteric site, altering the enzyme's shape

Cellular Signaling

• Hormones: Chemical messengers that transmit signals between cells
  • Produced by endocrine glands
  • Travel through the bloodstream to reach target cells
• Receptors: Proteins that bind to hormones or signaling molecules
  • Specific binding sites for hormones
  • Trigger a response in the target cell
• Signal Transduction: Pathway of molecular interactions that transmit signals
  • Involves a series of protein-protein interactions
  • Leads to a response in the target cell
• Second Messengers: Molecules that amplify signals
  • Examples include cAMP, IP3, and Ca2+
  • Produced in response to hormone binding

Laboratory Techniques

• Chromatography: Separation of molecules based on properties
  • Types include paper, gel, and high-performance liquid chromatography
  • Separate molecules based on size, charge, and polarity
• Electrophoresis: Separation of charged molecules based on size and charge
  • Types include agarose and polyacrylamide gel electrophoresis
  • Separate molecules based on size and charge
• Spectroscopy: Analysis of molecular structure using electromagnetic radiation
  • Types include UV-Vis, infrared, and NMR spectroscopy
  • Provide information on molecular structure and bonding