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What are the differentphospholipases that act to hydrolyze the ester linkages of thegroups attached to the various carbon atoms of glycerol? At whichcarbon atom of glycerol are you most likely to have arachidonatebound? Which of the phospholipases releases arachidonicacid? Which phospholipid is likely to have arachidonate as one ofthe acyl chains attached to glycerol? Whichphospholipase releases diacylglycerol and the phosphoryl headgroup?

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Elin Hessel
Elin HesselLv2
28 Sep 2019

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Related questions

Question 1


Which of the following provides the best description of adifference between prokaryotic and eukaryotic cells?.l.14.3>

The cell membrane of prokaryotic cells contains proteins, whilethe cell membrane of eukaryotic cells contains only lipids andcarbohydrates.

The DNA in eukaryotic cells is enclosed in the nucleus, whilethe DNA in prokaryotic cells is not separated from the rest of thecell’s contents.

Eukaryotic cells have cell walls that consist mainly of sugars,while prokaryotic cells do not.

Prokaryotic cells contain chloroplasts and mitochondria, whileeukaryotic cells do not contain specialized organelles.

Question 2

Cellular respiration is a process involving the breakdown ofglucose molecules in order to generate energy for cellularactivities. Given the general reaction below, which of thefollowing best describes the products labeled x andy?

C6H12O6 + O2 → _x___+ __y___ + energy.l.18.8>

The products are CO (carbon monoxide) andH2O2 (hydrogen peroxide), which thendecompose into carbon dioxide (CO2) and water(H2O).

The products are H2O (water) and CO2 (carbondioxide), which then undergo anaerobic respiration.

The products are CO2 (carbon dioxide) andH2O (water), which then become the reactants forphotosynthesis.

The products are O2 (oxygen) and H2O(water), which are then used for growth and to keep the organismhydrated.

Question 3

If a researcher added a quantity of phospholipid molecules to abeaker of water, what would be most likely to happen to theorientation of the phospholipid molecules?.l.14.2>

They would break apart, and the remaining lipid tails wouldfloat up and form a layer on the surface of the water.

Their lipid tails would align within a spherical double layerwith their phosphate heads in the water inside and outside thesphere.

They would form a single-layered sphere with the phosphate headspointing outward and the lipid tails pointing inward.

Their lipid tails would adhere to the glass of the beaker andtheir phosphate heads would float in the water.

Question 4

While looking at a cell under a microscope, a scientist is ableto see a biological molecule. This molecule is a nucleic acid witha ladder structure and contains the nitrogenous bases adenine,thymine, cytosine, and guanine. Based on this information, whatconclusion can the scientist draw regarding this nucleicacid?.l.18.1>

The nucleic acid is RNA and would be found in the cell’snucleus.

The nucleic acid is RNA and would be found in the cytoplasm.

The nucleic acid is DNA and would be found in the cytoplasm.

The nucleic acid is DNA and would be found in the cell’snucleus.

Question 5


Which of the following is needed for cellular respiration tooccur?.l.18.8>

Sodium

Oxygen

Water

Nitrogen

Question 6


What would be the most likely effect if the side chain of an aminoacid group was unable to vary its structure?.l.18.4>

The organism would not be able to make and store starches.

The organism would not be able to process glucose moleculeseffectively.

The organism would not be able to regulate the creation ofspecialized cells.

The organism would not be able to make more than one type ofprotein.

Question 7


During photosynthesis, unused oxygen atoms form oxygen gas(O2) which is released as a waste product. How did theseoxygen atoms originally enter the plant?.l.18.7>

They were part of the ATP molecules gathered by thechloroplasts.

They were part of the sugar molecules(C6H12O6) the plant brought in forfood.

They were part of the carbon dioxide (CO2) moleculesthat entered through the leaves.

They were part of the water molecules (H2O) pulled inthrough the roots.

Question 8


Which of the following organelles houses DNA in eukaryoticcells?.l.14.3>

Endoplasmic reticulum

Golgi apparatus

Nucleus

Mitochondrium

Question 9


M. J. Schleiden shifted the scientific community's attention tocellular processes with his.l.14.1>

attention to disproving spontaneous generation

publication of ideas on cell generation

theories on the division of cells

claim that cells were the basic unit of all plant matter

Question 10


While the average human is able to hold his or her breath forapproximately one minute, a whale can dive for over 30 minuteswithout returning to the surface. Which of the following correctlydescribes this difference?.l.18.10>

Whales need less energy than humans.

Whales gather energy from their environment better thanhumans.

Whales are able to tolerate the products of cellular respirationbetter than humans.

Whales have a slower cellular respiration metabolism rate thanhumans.

Question 11


What can you conclude about the advantage of the cell membranehaving hydrophobic ends in the phospholipid bilayer?.l.18.3>

The cell requires the ability to digest and eliminateenzymes.

The cell requires a barrier between itself and itsenvironment.

The cell requires a means to store starches and glucose.

The cell requires a structure for eliminating waste.

Question 12


What would be the most likely outcome if the ribosomes of a cellwere damaged and stopped functioning?.l.14.3>

The cell would lose structure and shape.

Cell growth and repair would slow or stop.

Cell waste would no longer be processed.

The cell would produce more mitochondria.


This problem is about the relationship between the structure and function of the enzyme isocitrate dehydrogenase (IDH), which catalyzes the oxidation of isocitrate and subsequent decarboxylation (see Chapter 16 for more details):

isocitrate + NAD(P)+ ® a-ketoglutarate + CO2 + NAD(P)H + H+
This is one of the reactions in the TCA cycle, and is tightly regulated. One of the ways in which

IDH is regulated in E. coli is by phosphorylation of serine 113, which inhibits it. You will examine the crystal structures in the following PDB files:

PDB ID#

Description

1IDH

Enzyme complexed with NADP+, isocitrate, and Ca2+

2IDH

Enzyme complexed with isocitrate, Mg2+

3IDH

Enzyme phosphorylated at Ser113

4IDH

Mutant enzyme with Ser113 converted to Glu

1) Briefly describe the overall tertiary and quaternary structure of IDH.
(You can use any of the PDB files for this. Approach this as you did in Problem 1.) What kind of domains does it have (e.g. what class)?
What sort of symmetry does the quaternary structure possess?
Briefly describe the dimerization interface – how are the 2 subunits held together? (e.g. Describe how the secondary structural elements come together.)

2) Examine the active site in 1IDH. Which amino acids are part of the sites binding the substrates? Fill out the tables on the next pages for the most important residues you identify for IDH’s function. For the column in which you report distances, indicate which atoms you used to measure the distance (of the amino acid and the substrate or effector).

a)Residues most important for binding isocitrate (“ICT1418”)

Residue (name & #)

Atom comes from which part of the residue? Interacts with which atom of isocitrate? Type(s) of interaction (e.g. H-bond, charge-charge)

distance

between atoms (Å) & 2° structural context

B) Residues most important for binding NADP+ (Note: “d1417” is the NADP+ associated with Chain A, while “NAP1417” is the NADP+ associated with Chain B.)

C) Residues important for binding Ca2+ (which likely is where Mg2+ binds)

3) Write below a proposed mechanism for the IDH-catalyzed reaction. Include at least 3 residues that would be involved in such a mechanism, and briefly explain what each is doing (e.g. acting as acid/base at a specific step, stabilizing a specific intermediate state, etc.)

Could you please proof read my work (Scientifically and correctgrammar) on mangroves issues regardingSocial, Economical, Environmental and Political areas. I wouldhighly appreciate your help.

Here itis:

Issues:

The mangrove forests provide at least US $1.6 billion each yearin ecosystem services as it acts as bases for successful fishingand prawning industry since it provides breeding, feeding andnursery areas for marine species worldwide. Studies in EasternAustralia have estimated that around 67% of the entire commercialcatch is composed of species dependent upon mangrove estuarineareas. The northern Prawn fishery, one of the most valuablefisheries in Australia which is lined by mangrove communities,injects millions of dollars each year into the NT economy. Forexample, In 1996/97 around 3266 tonnes of prawns were produced fromNT waters, valued at around $51 million. In addition, approximately$7.5 million of mud crab and $3.3 million of barramundi were caughtin the NT.

Also in countries such as Belize in USA, theannual economic benefits from reef and mangrove dependent fisheriesis estimated at between US$14–16 million. Furthermore, mangrovesalso benefit the economy by providing recreational facilities forexample, in 2007 many coastal Belizeans Coral reef- andmangrove-associated tourism contributed an estimated US$150 millionto $196 million to the national economy (12 percent to 15 percentof GDP).

Additionally, mangrove forests provide thesociety across the globe with huge range of 'ecological services'such as providing a source of timber which can be used to builddwellings and boats, fuel-wood for cooking and heating sinceAvicennia woods have a high calorific (heating) value,food and traditional medicines for example, the bark ofAvicennia marina can be used to treat stingray stings. Allof these mangrove products can raise the economy of the country bybeing sold by the individuals that collect them. For example, incountries such as Sri Lanka, the collective mangrove productsrepresent a total gross value of US$ 1,171/household/year. Theycontribute to the income of poor, medium and rich income categoryby approximately 42%, 37% and 21% respectively.

Mangroves are also food sources for thesurrounding ecosystems. In New South Wales, it was reported thatone square kilometre of mangrove forest contributes to about 600tonnes of plant material each year to the estuary food chain. Also,mangroves also provide birds sanctuary for northern hemispherebirds. For example, it was reported that a wide variety of 128 birdspecies have been found inhabiting mangroves in Darwin Harbour.

They also provide students with valuable sourcefor understanding the complex scientific interrelationshipsinvolved in the mangrove ecosystem for example linking the changesin abiotic factors with the changes in the biotic factors along themangroves intertidal zone.

Mangroves can also act as barriers againsttsunamis, cyclones and hurricanes. Empirical and field basedevidence is limited, but analytical models show that 30 trees per100m2 in a 100m wide belt may reduce tsunami flow rateby as much as 90%. For example in 1960 a tsunami hit the coast ofBangladesh in an area where the mangroves were intact. No-one died.These mangroves were subsequently cut down by the shrimp (prawn)farming industry and in 1991 thousands of people were killed when atsunami of the same magnitude hit the same region.

Mangroves create a physical barrier, slowingwater movement from the land and trapping sediments. Accordinglythey make land and reduce the erosion along estuaries and creeksand by doing so, they reduce contaminants and sediment run up intothe water and act as natural bio-filters, maintaining the health ofcoral reefs and coastal habitats.

Furthermore, the mangrove forests play animportant role in sequestering coastal carbon from the atmosphereand dissolving it into the ocean. Although the intertidal mangroveforests cover only 0.1% of the earth's surface, they contribute upto 10 % worldwide of the ocean's dissolved organic carbon. This isapproximately equal to the amount reaching the ocean from theAmazon river, the largest single source of dissolved organiccarbon.

Unlike CO2 absorbed directly from theatmosphere, much of the carbon produced by mangrove trees is boundup in large molecules which are highly resistant to decomposition,and is therefore likely to be held in the ocean for decades insteadof being returned to the atmosphere as carbon dioxide.

Due to the extractive activities in mangrove forests inAustralia such as the illegal collection of crabs and mangroves'fruits for medicinal purposes as well as timber harvesting, thegovernment and several agencies have introduced laws to protect themangorve forests. For example on the 1st of March 2009,in Queensland, the Government introduced green zones which protects16 % of the Moreton bay marine park. The Government has placed, a$21 million investment in the park which includes a $15 millionStructural Adjustment Program to reduce the environmental andeconomic effects of commercial fishing effort displaced by the newzoning arrangements by purchasing commercial fishing licences

Another example is that in 2003, 465 km2 ofmangroves and associated habitats around Darwin Harbourwere zoned conservation areas by several agencies, including EPA (Environmental protection Agency), DPI ( Department of planning andinfrastructure) and several others, under an amendment to theNorthern Territory Planning Scheme. This includes 95.6% ofmangroves in the harbour. Also, in South Australia, 28% of themangroves are lying within protected areas that are covered by anumber of acts set by the government

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