Ecology Systems

• Matter, energy, and life are interconnected topics
• Students will learn about systems, conservation of matter, organic compounds, thermodynamics, photosynthesis, and respiration

System Definition

• A system is an interconnected network of components and processes
• Materials and energy flow from one component to another within a system
• An ecosystem is a complex system with animals, plants, and the environment through which energy and materials move

Simple Systems

• Simple systems have compartments storing energy or matter, also known as state variables
• Flows, or pathways, are how resources move between compartments
• Understanding ecological systems helps in diagnosing disturbances or changes

Types of Systems

• Open systems receive inputs from and produce outputs to their surroundings
• Closed systems exchange no energy or matter with surroundings, but they're rare
• Throughput is the flow of energy and matter into, through, and out of a system
• Stable systems have equal inputs and outputs; 100 kg of nitrogen entering a system results in 100 kg being exported

Feedback Loops

• Positive feedback increases a process component
• Negative feedback diminishes a process

Emergent Properties

• Characteristics of a whole system are greater than the sum of its parts

Elements of Life

• Matter takes up space and has mass
• Matter follows the principle of conservation of matter: matter is neither created nor destroyed, but recycled

Matter Composition

• Matter is made of elements, substances that can't be broken down by chemical reactions
• Key elements include C, H, O, and N
• Atoms, the smallest particles of an element, exhibit its characteristics

Molecules and Compounds

• Atoms form compounds, substances with different kinds of atoms
• Molecules are pairs or groups of atoms that can exist as a single unit

Organic Compounds

• Carbon is a key element, forming chains/rings for organic compounds in biomolecules and living organisms
• Four major categories of organic ("bio-organic") compounds in living things: lipids, carbohydrates, proteins, and nucleic acids

Lipids

• Lipids, like fats and oil, store cellular energy
• They form the core of cell membranes and other structures

Carbohydrates

• Carbohydrates, like sugar, starches, and cellulose, store energy and provide cell structure

Proteins

• Proteins provide cell structure for countless cell functions
• They identify microbes, move muscles, transport oxygen, and regulate cell activity

Nucleotides

• Nucleotides signal between cells, tissues, and organs and provide energy within cells
• DNA stores and expresses genetic information

Cells

• All living organisms are composed of cells
• Cells are minute compartments where processes of life occur

Energy

• Energy is defined as the ability to do work
• It's measured in heat (calories) or work (joules) units
• Kinetic energy is the energy contained in moving objects
• Potential energy is stored and available for use

Chemical Energy

• Chemical energy in food and gasoline are potential energy examples that can be used to do some work
• Heat is transferable energy between objects of different temperatures

Thermodynamics

• Thermodynamics explains the transfer of energy in natural processes
• Deals with the rates of flow and transformation of energy from one form or quality to another

Thermodynamics Laws

• The first law of thermodynamics states that energy is conserved
• Energy is neither created nor destroyed under normal conditions
• According to the second law of thermodynamics, energy is available to do work with each successive energy transformation

Obtaining Energy

• Solar energy is essential for life for both warmth and life-sustaining energy:
  • Photosynthesis converts radiant energy into chemical energy in organic molecules
  • Cellular respiration releases chemical energy

Photosynthesis vs. Cellular Respiration

• Photosynthesis: 6CO₂ + 6H₂O + Energy → C₆H₁₂O₆ + 6O₂
• Cellular Respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy

Biogeochemical Cycles

• Elements and compounds that sustain living things are endlessly cycled through living things and the environment
• These cycles include the hydrologic, carbon, nitrogen, phosphorus, and sulfur cycles

Hydrologic Cycle

• Most of Earth’s water is stored in the oceans
• Solar energy evaporates this water, and winds distribute water vapor around the globe
• Precipitation over land is 111,000 km³, and over the ocean, it's 385,000 km³
• Evaporation from the ocean totals 425,000 km³

Water's Role

• Water moves through living things and the atmosphere
• It helps with metabolic processes within cells
• It maintains nutrient flows through ecosystems, and for global scale distribution of heat and energy

Carbon Cycle

• Carbon is a structural component of organic molecules and chemical bonds in carbon compounds which provide metabolic energy

Nitrogen Cycle

• Organisms cannot exist without amino acids, peptides, and proteins that contain nitrogen
• This component makes up 78% of the air and is a primary component of household and agricultural fertilizers

Phosphorus Cycle

• At the cellular level, energy-rich, phosphorus-containing compounds are essential for energy-transfer reactions
• Phosphorus is transported in water
• Producer organisms take in inorganic phosphorus, incorporate it into organic molecules, and passes it on to consumers

Sulfur Cycle

• Sulfur plays a vital role in organisms as an essential component of proteins
• Sulfur compounds determine the water, acidity of rainfall, and soil acidity
• Most of Earth's sulfur is stored underground in rocks and minerals

The quiz covers the concept of systems in ecology, energy throughput, feedback loops, conservation of matter, emergent properties and bio-organic compounds. It also touches on the laws of thermodynamics.