Characteristics of Organisms and Metabolism

Characteristics of Organisms

• Organisms grow and develop
• Organisms change over time
• Organisms respond to their environment
• Organisms maintain homeostasis
• Organisms have a genetic code
• Maintaining a stable internal environment is a key characteristic of life.

Specialized Plant Cells

• Plants exchange gases (CO2, O2, H2O) through tiny openings called stomata.

Chemical Energy and ATP

• ATP (adenosine triphosphate) is the base energy source for all cells.
• ATP is composed of adenine, ribose, and three phosphate groups.

Cellular Respiration and Photosynthesis

• Cellular Respiration

  • Occurs in stages - Glycolysis, Krebs Cycle, Electron Transport Chain
  • Location:
    • Glycolysis - Cytoplasm
    • Krebs Cycle - Matrix of Mitochondria
    • Electron Transport Chain - Membrane of Mitochondria
  • Raw Materials: Oxygen, Glucose, Carbon Dioxide, Water
  • Waste Products: Carbon Dioxide, Water, Oxygen
  • Major Products: ATP, Sugars, Energy (Electrons)
  • Energy source: Electrons
  • Note Energy source = the sun

• Photosynthesis

  • Occurs in stages - Light Dependent, Light Independent
  • Location:
    • Light Dependent - Thylakoids
    • Light Independent - Stroma
  • Raw Materials: Carbon Dioxide, Water, Light
  • Waste Products: Oxygen
  • Major Products: Sugars, Energy (ATP)
  • Energy source: Sun

Photosynthesis Experiments

• Van Helmont: Plant mass gain is primarily from water.
• Priestley: Plants release oxygen.
• Jan Ingenhousz: Light is essential for photosynthesis.

Definitions

• Homeostasis: Maintaining a stable internal environment (e.g., temperature, glucose levels).
• Autotroph: Organism that makes its own food (e.g. Plants).
• Heterotroph: Organism that eats other organisms (e.g., Humans).
• Cell Specialization: Cells develop differently to perform specific tasks.
• Cell Culture: Growing cells outside their natural environment in controlled conditions.
• Cell Fractionation: Separating different cell parts using techniques such as centrifuges
• Centrifuge: Device to separate cells.
• Intraspecific Competition: Competition within the same species
• Interspecific Competition: Competition between different species
• Predation: When one organism captures and consumes another.
• Symbiosis: Two species living closely together.
• Mutualism: Both species benefit from the relationship.
• Commensalism: One species benefits, the other is neither helped nor harmed.
• Parasitism: One organism benefits, the other is harmed.
• Cell Wall: Rigid outer layer of plant cells, outside the cell membrane.
• Cell Membrane (Plasma Membrane): Double layer of lipids and proteins surrounding the cell.
• Prokaryote: Cell without a nucleus (e.g., bacteria).
• Eukaryote: Cell with a nucleus (e.g., plants, animals).
• Diffusion: Movement of particles from high concentration to low concentration.
• Osmosis: Movement of water across a selectively permeable membrane.
• Hypertonic: Higher solute concentration than another solution.
• Hypotonic: Lower solute concentration than another solution.
• Isotonic: Equal solute concentration as another solution.
• Lactic Fermentation: A metabolic process in which glucose is converted into energy in the absence of oxygen.

Explore the key characteristics that define living organisms, including their growth, development, and ability to maintain homeostasis. Additionally, delve into the processes of cellular respiration and photosynthesis, and understand the role of ATP as the energy currency in cells.