Biomolecules and Energy Calculation

Biomolecules

• Carbohydrates: Provide energy and structural support

  • Monosaccharides: Simple sugars (e.g., glucose)
  • Polysaccharides: Complex sugars (e.g., starch, glycogen)
  • Examples: Glucose (C₆H₁₂O₆), starch (plant energy storage), glycogen (animal energy storage)

• Lipids: Store energy, insulate, and form cell membranes

  • Types: Fats, oils, phospholipids, steroids
  • Structure: Glycerol + fatty acids
  • Examples: Saturated fats (solid at room temperature), unsaturated fats (liquid at room temperature)

• Proteins: Perform diverse functions; enzymes, structural support, transport, and immunity

  • Structure: Chains of amino acids linked by peptide bonds, organized into primary, secondary, tertiary, and quaternary structures
  • Examples: Hemoglobin, collagen, enzymes like amylase

Atwater System

• Method to calculate food energy content
• Energy values (kcal/g):
  • Carbohydrates: 4
  • Proteins: 4
  • Lipids: 9
  • Alcohol: 7
• Used in nutrition to determine food energy.

Data Presentation

• Data Tables: Organize data for analysis.

  • Include column headings (variables), rows (data points), and units.
  • Key: Clarity, precision, and correct labeling.

• Data Graphs: Visualize data trends and comparisons

  • Types: Bar graphs (comparing quantities), line graphs (showing trends over time), pie charts (showing proportions)
  • Elements: Clear labels (axes, units), title, appropriate scales.

Cell Theory

• Core tenets:
  • All living things are made of cells.
  • Cells are the fundamental units of structure and function.
  • Cells arise from pre-existing cells.

Domains of Life

• Bacteria: Prokaryotic, unicellular organisms, no membrane-bound organelles.

• Archaea: Prokaryotic, unicellular, distinct from bacteria, often adapted to extreme environments.

• Eukarya: Eukaryotic, including unicellular and multicellular organisms (plants, animals, fungi, protists), cells with membrane-bound organelles.

Cell Types

• Prokaryotic Cells: Lack a nucleus, smaller, simpler structure, DNA in a nucleoid region (e.g., bacteria, archaea)

• Eukaryotic Cells: Contain a nucleus, larger, more complex, membrane-bound organelles (e.g., animals, plants, fungi, protists)

Cell Structures

• Nucleus: Contains DNA, controls cell activities.

• Mitochondria: "Powerhouse of the cell," generate energy via cellular respiration.

• Ribosomes: Synthesize proteins.

• Endoplasmic Reticulum (ER):

  • Rough ER: Studded with ribosomes, involved in protein synthesis.
  • Smooth ER: Involved in lipid synthesis and detoxification.

• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

• Lysosomes: Contain digestive enzymes that break down waste.

• Cytoskeleton: Provides structural support and facilitates cell movement.

• Cell Membrane: Regulates what enters and exits the cell, selectively permeable.

Animal vs. Plant Cells

• Animal Cells: Lack cell walls, have smaller vacuoles, and contain centrioles.

• Plant Cells: Have cell walls made of cellulose, a large central vacuole, and chloroplasts for photosynthesis.

Passive Transport

• Movement across the cell membrane without energy input.
  • Diffusion: High to low concentration.
  • Facilitated Diffusion: Uses transport proteins to move molecules.
  • Osmosis: Water movement across a membrane.
• Key concepts: Concentration gradients, equilibrium, hypertonic, hypotonic, isotonic solutions.