Trade-offs in Homeostasis and Metabolism of Organisms

Trade-offs

Competing investments affecting organism performance.

Fecundity

Number of offspring and investment level.

Growth

Size and strength versus defense capabilities.

Longevity

Duration of individual survival.

Metabolizable Energy Intake (MEI)

Energy absorbed by organisms at varying temperatures.

Eastern Fence Lizards

Species studied for temperature and energy intake.

Optimum Temperature

Ideal temperature range for maximum performance.

Acclimation

Short-term physiological changes to environmental shifts.

Adaptation

Long-term physiological changes in response to environment.

Evolution

Change in allelic frequencies over time.

Photosynthesis

Conversion of light to energy in plants.

Photosynthetic Rate

Rate at which plants convert light energy.

Homeostasis

Regulation of internal conditions for optimal performance.

Ectotherm

Organism relying on external heat sources.

Endotherm

Organism generating internal heat for temperature control.

Poikilotherm

Organism with variable body temperature matching environment.

Homeotherm

Organism maintaining constant body temperature despite changes.

Stenotherm

Organism surviving only within narrow temperature ranges.

Regulation

Mechanisms maintaining internal temperature and chemistry.

Temperature Variability

Fluctuations in temperature affecting organism performance.

Optimal Performance Zone

Range where organisms perform best.

Environmental Conditions

Factors influencing organism performance and survival.

HS

Total heat stored in an organism.

Hm

Heat gained via metabolic processes.

Hcd

Heat gained/lost through conduction.

Hcv

Heat gained/lost through convection.

Hr

Heat gained/lost via electromagnetic radiation.

He

Heat lost through evaporation.

Convection

Heat diffusion through gas.

Conduction

Heat diffusion through liquid or solid.

Radiation

Electromagnetic movement of heat.

Poikilotherm

Organism with variable body temperature.

Endotherm

Organism generating heat metabolically.

Stenotherm

Organism with narrow temperature tolerance.

Insulation

Anatomical features reducing heat loss.

Counter Current Heat Exchange

Mechanism for conserving heat in organisms.

Rete mirabile

Network of blood vessels for heat exchange.

Surface to volume ratio

Influences heat retention in organisms.

Thermal inertia

Ability to resist temperature changes.

Bradycardia

Reduced heart rate during dives.

Vasoconstriction

Blood shunted to maintain core temperature.

Sweating

Physiological response to cool the body.

Behavioral adaptation

Actions taken to maintain temperature homeostasis.

Thermal Neutral Zone

Temperature range with stable metabolic rate.

Aquatic endotherms

Endotherms facing unique challenges in water.

Hs

Heat storage equation: Hs = Hcd ± Hcv ± Hr

Hcd

Heat gained through conduction from surroundings

Hcv

Heat lost or gained through convection

Hr

Heat gained or lost through radiation

Desert plant adaptations

Decrease conduction, increase convection, reduce radiation

Arctic plant adaptations

Increase radiation, decrease convection for warmth

Araceae lilies

Use stored starch for heat in spring

Water regulation in animals

Maintain water concentration through loss and gain

Water balance equation

Wd + Wf + Wa - We - Ws

Wd

Water gained through ingestion

Wf

Water gained through metabolism of food

Wa

Water absorbed from the environment

We

Water lost through evaporation

Ws

Water lost through secretion

Transpiration

Water evaporation from plant surfaces

Potential Evapotranspiration (PET)

Water loss potential for plants in environment

Metabolism

Transforming environmental energy into usable energy

Photosynthesis equation

CO2 + H2O → CH2O + O2 using light

Respiration equation

CH2O + O2 → CO2 + H2O releasing energy

Photosynthetic autotrophs

Organisms using light and CO2 for energy

Chemosynthetic autotrophs

Organisms using inorganic molecules for energy

Heterotrophs

Organisms obtaining energy from organic molecules

Metabolic diversity

Variety of energy acquisition methods in organisms

Prokaryotic diversity

Includes autotrophy and heterotrophy for carbon

Nitrosomas

Bacteria involved in nitrogen oxidation.

Beggiatoa

Bacteria that oxidize hydrogen sulfide.

Eukaryotes

Organisms with membrane-bound nucleus and organelles.

Autotrophy

Organisms that fix CO2 for carbon.

Heterotrophy

Organisms that consume organic molecules for carbon.

Photo-autotrophy

Using light to convert CO2 into organic compounds.

Chemo-autotrophy

Using inorganic compounds for energy and carbon.

Cyanobacteria

Photosynthetic bacteria that produce oxygen.

Sulfur bacteria

Bacteria that use hydrogen sulfide for energy.

Photosynthetically Active Radiation (PAR)

Light useful for photosynthesis, ~400 to 700 nm.

C3 Photosynthesis

Carbon fixation using RuBisCO, producing 3-carbon sugar.

C4 Photosynthesis

Uses 4-carbon acid, separates fixation and synthesis.

CAM Photosynthesis

Separates fixation and synthesis by time of day.

RuBisCO

Enzyme that catalyzes CO2 fixation in plants.

Photorespiration

Wasteful reaction using RuBisCO, reduces efficiency.

Light Reaction

Initial phase of photosynthesis, converts light to energy.

Calvin Cycle

Second phase of photosynthesis, fixes carbon.

Stomata

Pores on leaf surfaces for gas exchange.

Bundle Sheath Cells

Cells in C4 plants where Calvin cycle occurs.

Mesophyll Cells

Cells in C4 plants where light reaction occurs.

Vacuole

Storage organelle in plant cells for acids.

Prokaryotes

Unicellular organisms without a nucleus.

Heterotrophs

Organisms relying on organic matter for energy.

Chemosynthetic Autotrophs

Bacteria and Archaea using inorganic compounds for energy.

Inorganics

Non-organic compounds like ammonium and nitrate.

Sulfur oxidizers

Use CO2 and sulfur compounds for energy.

Nitrosomas

Bacteria involved in nitrogen cycling.

E. coli

Common bacterium found in intestines.

Cyanobacteria

Photosynthetic bacteria producing oxygen.

Halophiles

Archaea thriving in extremely salty environments.

Thermophiles

Archaea living in high-temperature environments.