Lab 4. Overview Instructor collects lab. 3 write ups and

checks pre-labs. in lab notebook Discussion of graded plant density write up.

Overview of Community Energy Flow, Soil, & Microorganism Colonies.

Soil composition determination

Plant pigment chromatography - Complete and turn in in-class exercise

Microbial species richness data

Soil animals

Exercise due in Lab 5 discuss. & questions

Communities Community = A group of SPECIES living in

the same area that have the potential for interaction.

Species Richness = number of SPECIES in a given area (community).

Photosynthesis captures light energy in the molecule glucose.carbon dioxide (6 CO2) + water (6 H2O) + light →

glucose (C6H12O6 ) + oxygen (6 O2).

Photosynthesis = primary production

Most organisms (including plants) break down glucose to get usable energy.Glycolysis & Cellular Respirationglucose (C6H12O6 ) + oxygen (6 O2) →

carbon dioxide (6 CO2) + water (6 H2O) + 36 ATP biotic energy

Energy in Communities

Plant Photosynthesis & Respiration

6 CO2

6 H2O

6 O2

C6H12O6

(energy)

light(energy)

photo-synthesis

32 ATP(energy used

by plant)

extraglucose (energy)used for structure

ascellulose

extraglucose (energy)stored

as starch

glycolysis &respiration

otherorganisms

can get glucose (energy)

from eatingstarch &/orcellulose

Chlorophyll & Chromatography Chlorophyll = large molecule that traps violet/blue

& orange/red light as part of photosynthesis (reflects green/yellow)

Chromatography = method to separate molecules using a solvent and paper.We will use usechromatography to separate chlorophyll and other plant pigments.

Soil Abiotic Soil Components = small pieces

of “rock” (smaller) clay—silt—sand—gravel (larger)

Biotic Soil Components = small decomposing plants = organic material

Particle size and organic material affect soil nutrients, water retention, and permeability.

Water & nutrient availability often limit primary production by plants. sand

silt

clay

Soil Composition Determination

Microorganism Colonies Microbial Colony = a cluster of bacteria or fungi on

solid nutrient medium; the descendants of a single bacterium or fungal spore.

Microorganisms often differentiated based on colony characteristics.

Microbial Colonies

Today’s Activity Reminders READ the instructions () in the manual.

Mix the hell out of the soil. We’re testing in test tubes which requires a greater amount of agitation to mix.

Don’t disturb once mixed and your first line is drawn on the outside of the test tube.

Work quickly with the acetone when putting plant pigment on the paper. It evaporates fast. Don’t inhale the chromatog. solvent.

Do not open the microbial plates. Leave the Parafilm around the edges.