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level: Eukaryotes

Questions and Answers List

level questions: Eukaryotes

QuestionAnswer
What are pieces of information content found in biomarkers and are species specific?carbon skeleton, type and positions of functional groups, stereochemistry and isotope content (13C, 14C, 2H, 15N, 34S, etc.)
Species-specific biosynthesis relys on the principle that:same amount of C’s and H’s but different structure, functional groups or d13C  can tell us about the species specific biosynthesis/pathway of synthesizing the lipid/environment
diagenesis and catagenesis ...increase loss of information during the increasing burial and time
Over time the carbon skeleton may survive,, but the functional groups may get lost, this causes ...it to become more difficult to recognize the original biomarker and thus the source organism
Over time dinosterol may turn into... (dia/catagenesis)dinosterene (loss of OH, substituted by double bond) and dinosterane (loss of double bonds, replaced by H's?)
What kind of organisms make dinosterol?Eukaryotes (sterol! 3 cyclohexane, 1 cyclopentane) - specifically dinoflagellates
Prokaryotesare organisms whose cells lack a nucleus and other organelles. Prokaryotes are divided into two distinct groups: the bacteria and the archaea. Most prokaryotes are small, single-celled organisms that have a relatively simple structure.
Eukaryotesare organisms whose cells contain a nucleus and other membrane-bound organelles. There is a wide range of eukaryotic organisms, including all animals, plants, fungi, and protists, as well as most algae. Eukaryotes may be either single-celled or multicellular.
RibosomesThe cell’s protein-synthesising factories, are composed of structural RNA and various proteins. Ribosomes are present in ALL cells and the sequence of the gene encoding for 16S or 18S ribosomal RNA is used for molecular phylogeny of all organisms.
Chlorophyll a = present in almost all phytoplankton species, a good biomarker for this is ?phytol (acyclic diterpene alcohol) is a good biomarker for algae! Due to diagenesis this may turn into phytane (no OH group) -> diterpene alcohol
A good biomarker for algae is polyunsaturated fatty acids, what is their disadvantage ?due to unsaturation they are quite unstable
IPL are the basic building blocks of cell membranes. They contain at least one .... headgroup. They are very good biomarkers because ?hydrophilic - Large structural variety in the fatty acid tails, types of bonds and also in the headgroups
Sterols occur generally in eukaryotes but are only directly biosynthesized by photosynthetic eukaryotes (algae and higher plants) and are used as membrane modifiers. What are these sterols?Look at the methyls and double bonds!dinosterol (dinoflagellates), "diatom"sterol, d7 sterol (double bond at 7), occur abundantly in green algae
the biosynthesis of steroids by algae need ...oxygen!
Why are sterols not the best biomarkers?They are not really exclusive to certain groups
Who make theseOccurs specifically in Chrysophyte algae (‘brown algae’)
who make theseOccurs in Porifera (“sponges”) (but also a bit in Chrysophytes, brown algae)
who makes this 27-nor?Kareniadinoflagellate algae (but also occur in other dinoflagellates as minor compounds)
Long chain alkyl diols (LCDs) are lipids consisting of linear even-numbered (28,30,32) alkyl chains with an alcohol group at the primary carbon atom and one at a midchain carbon position (13, 14,15). Who mainly make C28 & C39 1,14-diols (saturated and monounsaturated) and who mainly makes saturated C28-32 1,13- & 1,15-diols?Proboscia (diatoms) and Eustigmatophytes
Proboscia (diatom) lipids ar long chain diols - C28 & C30 1,14-diols (saturated or mono-unsaturated at C6), what are they related to/which environement are they most abundantupwelling an dnutreint-rich wates - upwelling zones
Occurrence of highly branched isoprenoid (HBI) alkenes are produced by...?a small number of marine diatoms (C25 and C30, with some double bonds)(specific genera: Rhizosolenia, Haslea, Pleurosigma, Navicula)
HBIs are found in two seperate diatom clusters, how could this be?convergent evolution
IP25 is a .... biomarker for ....highly branched isoprenoid (HBI) specific to arctic sea ice diatoms (seasonal! not permanent cover, need light!)
IPSO25 is a ... biomarker for ... . And what does its name stand for?highly branched isoprenoid (HBI) is specific for melting antarctic ice & Ice Proxy for the Southern Ocean with 25 carbon atoms
Long-chain alkenones (O double bond at second C-atom) are biomarkers for ....abundant haptophytes
There are 3 subgroups of haptophytes (for example: coccolithophores) that synthesise long chain alkenones, freshwater, alternating salinity and marine. Each sub group makes a different sort of alkenone. What are the differencesClusters differ in chain length (C37/C38/C39/C40) and double bond position and isomer
Botryococcus braunii is a sometimes abundant freshwater algae that contains extraordinary high amounts of hydrocarbons, what is the unique biomarker (hint in figure), if you find this, what can you say about the deposition?When you find botryococcene you know it is not marine but lacustrine (easier to get oil!)
The composition of membrane lipids of ciliates is determined by their diet and represent the oxic/anoxic state of the watercolumn. If they switch from making making sterols to tetrahymanol (triperpenoid), what happened?watercolumn switched from oxic to anoxic and the ciliated switched from eating algae (eukaryotes) to bacteria (bactiverous ciliates)
odd-carbon long chain n-alkanes are a biomarker for? what baout odd and short?higher plants vs marine plants
Who makes these abietic acids/simonelliteGymnosperms (nakedseeds)
Who makes these b-amyrins/tetra-aromatic triterpanesangiosperms (enclosed seed/flowering plants)
Who is making the oleanane biomarker (triterpenoid) and what do they originate fromdiagnostic biomarker of angiosperms- tetra-aromatic triterpanes /b-amyrin but lost double bonds
what is this and who made it?hopane - bacteria
what is this and who made it?sterane (see sterol structure) - eukaryotes
what is this and who made it?tetrahymanol (cyclic triterpenoid + alcohol group) - bactivirous ciliates
what is this and who made it?oleanane (cyclic triterpenoid) - angiosperms
what is this and who made it ?taraxerol - mangroves (cyclic triterpenoid, alcohol group (-ol), 1 double bond)
Lignin phenols trace ....vegetation input
levoglucose traces ..terrestrial biomass burning
who make sterols in their membrane lipids?eukaryotes (sterol = 3-cyclohexane, 1-cyclopentane & OH-group)
3-Methyl hopanoids are found in .... and also in ancient methane seep sediments with 13C-depleted values(mostly) aerobic methanotrophic bacteria