Title: Energy and Nutrient Relations
1Energy and Nutrient Relations
2Energy Sources
- Organisms can be classified by trophic levels.
- Autotrophs use inorganic sources of carbon and
energy. - Photosynthetic Use CO2 as carbon source, and
sunlight as energy. - Chemosynthetic Use inorganic molecules as source
of carbon and energy. - Heterotrophs use organic molecules as sources of
carbon and energy.
3Solar - Powered Biosphere
- Light propagates through space as a wave.
- Photon Particle of light bears energy.
- Infrared (IR) Long-wavelength, low energy.
- Interacts with matter, increasing motion.
- Ultraviolet (UV) Short wavelength, high energy.
- Can destroy biological machinery.
- Photosynthetically Active Radiation (PAR)
- Between two extremes.
4Photosynthetically Active Radiation
5Solar - Powered Biosphere
- PAR
- Quantified as photon flux density.
- Number of photons striking square meter surface
each second. - Chlorophyll absorbs light as photons.
- Landscapes, water, and organisms can all change
the amount and quality of light reaching an area.
6Light Spectrum and absorption
- plant pigments, chlorophyll a, b, carotenes,.
xanthophyll, leutin, anthocyanin
7What are the 3 types of photosynthesis, how do
they vary, give examples of each.
- C3 most plants ie. sunflowers
- C4 grasses most prairie grasses, big blue
stem - CAM desert succulents
8Photosynthetic Pathways
- C3 Photosynthesis
- Used by most plants and algae.
- CO2 ribulose bisphosphate (5 carbon sugar)
phosphoglyceric acid (3 carbon acid) - To fix carbon, plants must open stomata to let in
CO2 . - Water gradient may allow water to escape.
9C3 Photosynthesis
10Photosynthetic Pathways
- C4 Photosynthesis
- Reduce internal CO2 concentrations.
- Increases rate of CO2 diffusion inward.
- Need fewer stomata open.
- Conserving water
- Acids produced during carbon fixation diffuse to
specialized cells surrounding bundle sheath.
11C4 Photosynthesis
12Photosynthetic Pathways
- CAM Photosynthesis
- (Crassulacean Acid Metabolism)
- Limited to succulent plants in arid and semi-arid
environments. - Carbon fixation takes place at night.
- Reduced water loss.
- Low rates of photosynthesis.
- Extremely high rates of water use efficiency.
13CAM Photosynthesis
14Heterotrophic energy paths Using Organic
Molecules
- Three Feeding Methods of Heterotrophs
- Herbivores Feed on plants.
- Carnivores Feed on animal flesh.
- Detritivores Feed on non-living organic matter.
15Chemical Composition and Nutrient Requirements
- Five elements make up 93-97 of biomass of
plants, animals, fungi and bacteria - Carbon (COOH, ECT) all organic molecules
- Oxygen C0 almost all organics
- Hydrogen CH4 almost all organics
- Nitrogen NH3 protein
- Phosphorus P- BONES, TEETH
- All must either ingest or manufacture these
organic molecules.
16What function does each macronutrient serve for
living things?
- Carbon structural for fats, carbs and protein
- Oxygen oxidation energy production
- structural
- Hydrogen structural, energy
- Nitrogen DNA, proteins
- Phosphorus energy, APT
17Essential Plant Nutrients and needed as
supplements for non-plants (worksheet)
- Potassium
- Calcium
- Magnesium
- Sulfur
- Chlorine
- Iron
- Carbon
- Nitrogen
- Phosphorus
18Problems with Herbivores
- Substantial nutritional chemistry problems.
- Low nitrogen concentrations.
- Must overcome plant physical and chemical
defenses. - Physical - Cellulose lignin silica
- Chemical Toxins, Digestion Reducing Compounds
(seeds)
19Carnivores
- Must consume nutritionally-rich prey. Energy in
must be greater than energy out. Problems - Major energy input to catch, kill and eat prey
- Cannot choose prey at will.
- Prey Defenses
- Aposomatic Coloring - Warning colors.
- mimicry
20Carnivores
- Predators are usually selection agents for
refined prey defense. - Usually eliminate more conspicuous members of a
population (less adaptive). - Must catch and subdue prey - size selection.
- Predator and prey species are engaged in a
co-evolutionary race.
21Detritivores
- Consume food rich in carbon and energy, but poor
in nitrogen. - Dead leaves may have half nitrogen content of
living leaves. - Fresh detritus may still have considerable
chemical defenses present.
22Using Inorganic Molecules - chemotrophs
- 1977 - Organisms found living on sea floor.
- Near nutrients discharged from volcanic activity
through oceanic rift. - Autotrophs depend on chemosynthetic sulfur
bacteria.
23- 2 types Free-living forms living within
tissue of invertebrates.
24Food Density and Animal Functional Response
- Holling described (3) basic functional responses
- 1. Feeding rate increases linearly as food
density increases - levels off at maximum. - Consumers require little or no search and
handling time. - 2. Feeding rate rises in proportion to food
density. - Feeding rate partially limited by search/handling
time.
25Food Density and Animal Functional Response
- 3. Feeding rate increases most rapidly at
intermediate densities - (S-shaped).
26Optimal Foraging Theory
- Assures if energy supplies are limited, organisms
cannot simultaneously maximize all life
functions. - Must compromise between competing demands for
resources. - Principle of Allocation
27Optimal Foraging Theory
- All other things being equal,more abundant prey
yields larger energy return. Must consider energy
expended during - Search for prey
- Handling time
- Tend to maximize rate of energy intake.
28Optimal Foraging in Bluegill Sunfish
29Optimal Foraging By Plants
- Limited supplies of energy for allocation to
leaves, stems and roots. - Bloom suggested plants adjust allocation in such
a manner that all resources are equally limited. - Appear to allocate growth in a manner that
increases rate of acquisition of resources in
shortest supply.
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