Main sources of heavy metals in the environment 

Match the microbial methods of dealing with heavy metals to the right description

Match the three classes of metals to their descriptions

Match these metals accordingly

Pick all non-­‐toxic, non-essential metals; no known biological effects 

Toxic metalloids Ge, As, and Sb are predominantly anionic. Toxicity is caused by displacing essential metals from normal binding sites (AsO4^3-­ & Cd vs PO4^3-­ & Zn), inhibiting enzyme function and disrupting nucleic acid structure.

Sometimes microorganisms better tolerate toxic metals at high concentrations

Happenings after photosynthetic organisms could produce O₂

Group the heat-trappers correctly

Major greenhouse gases are the subject to the Kyoto Protocol. Pick them

 Activities releasing greenhouse gasses. Group accordingly

CO₂ in the atmosphere is the largest carbon sink/reservoir over carbonate rock in earth's crust

The end products of respiration are CO₂ and new cell mass 

More complex carbon cycle activities include anaerobic activity like

Pick the 3 most common organic polymers

Group the plant polymers

peroxidase. Free-­radicals generated help break-­down. Subunits taken up by microbes (white rot fungi) and degraded.

Methane is ___times more effective than CO₂ at trapping heat

Methylococcaceae and Methylocystaceae are

 We are working on a strategy to use methanotrophs in bioremediation of contaminated groundwater. What enzyme was the first identified to cometabolize methane and Trichloroethylene (TCE)?

The best-studied and most complex of the mineral cycles. It has the mineral nutrient in most demand by microbes and plants and 4^th most common element in cells.

Cells need organic N or reduced inorganic N 

Group the Nitrogen reservoirs

Link the types of Nitrogen fixation to their output

Atmospheric N₂ and H₂ (often from natural gas/petroleum) combined to form NH₃ under high P, high T and catalyst. This describes

Cyanobacteria like Anabena and Nostoc have specialized heterocysts with thick walls impermeable to O to aid N fixation

What is the end product of N fixation?

pyrimidines (nucleic acids) and N-­acetylmuramic acid (cell wall) is

inorganic forms 

Link the correct process depending on Carbon to Nitrogen ratios

Nitrification is therefore ‘nitrogen immobilization'

Primary denitrifying genera in soil

Denitrification is an aerobic process

Problems of Dentrification

Anaerobic Ammonium Oxidation (Anammox) is a process where ammonium oxidation occurs under anaerobic conditions using nitrite as a ____ . Responsible for 50% of the N₂ gas produced in the oceans.

 Anammox is used in the removal of ammonium from wastewater treatment (full-­scale plants in the Netherlands)

Nitrosamines are not highly cancerous in adults

N₂O is a by-product of denitification and an intermediate of nitrification.