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champagnebat265Lv1

28 Sep 2019

Can anybody help me with this, please?

"The average human can distinguish between shades of green that differ by only 1 nm in wavelength. But on average we can only distinguish between 3 nm of difference at the blue end of the spectrum and 5 nm of difference at the red end. Why? Your answer should explain ALL of these differences, including why we differentiate blues better than reds."

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Lelia LubowitzLv2

28 Sep 2019

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Study Guide for my Fermentation class. Please help me be sureand study the correct things for my midterm.

Define what fermentation is, discuss the history of theprocesses, and explain why we should care to studyfermentation?

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What is/are the difference(s) between traditional culturestarters and starters used for mass production? What are theadvantages and disadvantages of both?

What is the difference between homolactic and heterolacticfermentation? How are these processes similar? Give examples ofdifferent ferments which utilize each pathway.

Humans and microbes have evolved symbiotically over time througha process known as symbiogenesis. Bacterial fermentation to producefoods is included in this symbiotic evolution, but only recently.More than the majority of this symbiogenesis is a result ofinteractions between microbes and the human body. Give specificexamples of symbiotic relationships between microbes and our bodiesand the benefits of these relationships. Why are bacteria sucheffective coevolutionary partners?

Explain/examine the cultural significance of 3 of the fermentedproducts we have studied thus far.

In which ways is fermentation similar and different in othercultures when compared to fermentation practices utilized in theUnited States today? Explain and discuss 3 examples.

Your task is to write a complete set of instructions for abeginner with no equipment or knowledge of fermentation, describe abasic recipe and explan the tools you would need and theinformation you must know in order to complete the simple ferment.Tell why each tool or ingredient is used, provide a step by stepguide to your ferment, and reasoning behind why you decided to dowhat you did.

In American health today, we have a rise of the use ofmedications that cause the death of natural gut bacteria; this hasled to many health problems. Rises in leaky gut syndrome all theway to mental illnesses that could be linked to the insufficientpresence of healthy gut bacteria. Discuss this issue in more depthand explain how fermentation may be a solution.

fuchsiaox475

Please answer the question after reading the paragraph.

We have a global health challenge in our hands today, and that is that the way we currently discover and develop new drugs is too costly, takes far too long, and it fails more often than it succeeds. It really just isn't working, and that means that patients that badly need new therapies are not getting them, and diseases are going untreated. We seem to be spending more and more money. So for every billion dollars we spend in R&D, we're getting less drugs approved into the market. More money, less drugs. Now we have a whole pipeline of different organ chips that we are currently working on in our labs. Now, the true power of this technology, however, really comes from the fact that we can fluidically link them. There's fluid flowing across these cells, so we can begin to interconnect multiple different chips together to form what we call a virtual human on a chip. Now we're really getting excited.We're not going to ever recreate a whole human in these chips, but what our goal is is to be able to recreate sufficient functionality so that we can make better predictions of what's going to happen in humans. For example, now we can begin to explore what happens when we put a drug like an aerosol drug. Those of you like me who have asthma, when you take your inhaler, we can explore how that drug comes into your lungs, how it enters the body, how it might affect, say, your heart. Does it change the beating of your heart? Does it have a toxicity? Does it get cleared by the liver? Is it metabolized in the liver? Is it excreted in your kidneys? We can begin to study the dynamic response of the body to a drug. Organs on chips could also change the way we do clinical trials in the future. Right now, the average participant in a clinical trial is that: average. Tends to be middle aged, tends to be female. You won't find many clinical trials in which children are involved, yet every day, we give children medications, and the only safety data we have on that drug is one that we obtained from adults. Children are not adults. They may not respond in the same way adults do. There are other things like genetic differences in populations that may lead to at-risk populations that are at risk of having an adverse drug reaction. Now imagine if we could take cells from all those different populations, put them on chips, and create populations on a chip. This could really change the way we do clinical trials. And this is the team and the people that are doing this. We have engineers, we have cell biologists, we have clinicians, all working together. We're really seeing something quite incredible at the Wyss Institute. It's really a convergence of disciplines, where biology is influencing the way we design, the way we engineer, the way we build. It's pretty exciting.

Question: For years, technology and medicine have joined together to pave the way or even solve some of the worldâs greatest issues in healthcare. These issues include but are not limited to incurable diseases and disorders like AIDS and cancer. According to Geraldine Hamilton however, we as a population are spending too much money to develop drugs and solutions to these issues, only to be at a deficit with the drugs actually produced. She believes that one of the keys is how we test these drugs and finding more efficient ways to do so. As a result, she suggests the use of organs on chips, an innovation created and pioneered by her lab. The use of organs on chips could change the way new drugs are released and tested, thus possibly furthering the process of creating solutions to healthcareâs problems. Where is the fine line between technology and human innovation? Is human innovation gradually becoming depending on technology? (At least two paragraphs, a paragraph is at least 5 sentences long.)

I'm having trouble simplifying this 6 question paper. Pleaserewrite this then post in comments. thanks! just 1-5 senstences perquestion please. please!

1.Among systems for study of macro evolutionary change (e.g.,major change in anatomy, moving from water to land or vice versa,acquisition of flight, etc.), the cetaceans have become the 'posterchild'. Explain why cetaceans are a better system in which to studyevolutionary transitions than each of the following vertebrategroups:

Cetaceans have primitive taxa thatrecords sequences of change at three critical phases:

-Initial aquatic specialization

-Evolution of filter feeding withbaleen

-Derivation of echolaction.

Divergence times in cetaceans areconducive to detection of positive selection and inactive loci.Evolutionary splits in cetacea are deep enough to provide adequatechange for statistically robust analyses of molecular evolution butare not so deep that substitution patterns are saturated andrecognition of pseudogenes is hindered.

They have an impressive fossilrecord.

Whole genomes for both cetaceans andterrestrial cetartiodactyles can illuminate transitions andcandidate loci associated with aquatic features and degenerativeevolution have been characterized by several research groups.

turtles: highly derived taxa but areancient clades and more difficult to study from a molecularperspective.

manatees: The extant diversity ofaquatic manatees is limited.

bats: have a poor fossil record.

pterosaurs (ancient winged reptiles):Lack genetic Data.

2. What is myoglobin?

A myoglobin is a small 153-amino acidprotein that is the primary carrier and storage center of oxygen inmuscle.

Explain why increased diving ability should be correlated withspecific types of replacement mutations of the gene encoding theprotein myoglobin.

Amino acid replacement that increasedcharge occurred overwhelmingly in lineages of extreme divers withsemiaquatic or aquatic lifestyles. The greatest increase in chargeoccurred independently in cetaceans, pinnipeds, and the bever, allof which share at least two convergent amino acid replacementswithin each lineage.

What specific kinds of amino acid replacements are favored bypositive selection when increased diving ability is favored?

High net surface charge enableselectrostatic repulsion that might reduce deleterious selfassociation of myoglobin molecules; protein folding stability couldhave a similar impact by limiting the percentage of misfoldedmolecules at high expression levels.

Explain how the maximum dive capability of an extinct whalespecies can be estimated.

By combining body mass with inferredconcentration of myoglobin based on net surface charge they wereable to estimate the maximum dive times of extinct cetaceans.

3. What is the general function of the protein prestin?

Is involved in conferringelectromotility to the outer hair cells of the cochlea, enablingsensitive to sound by driving the cochlear amplifier.

Explain why a phylogenetic treereconstructed using the characters of prestin amino acid sequencesshowed at first that the whales form a subgroup within thebats!

A phylogenetic analysis of prestinamino acid sequences supported a tree in which some odontocetecetaceans were nested within bats with high support, despitephylogenetic analsysts of nucleotides sequences favoring a moredistant relations.

This pattern was driven by convergentamino acid changes in that were shared between toothed whales andecholocating bats.

4. Relative to terrestrial mammals, what changes occurred togive deep diving cetaceans 'rod monochromacy'?

Rod monochromancy is unique amongmammals due to extreme adaptation to low light levels.

What is the advantage of rod monochromacy?

Allows you to see in low lightlevels.

Why does it make sense that rhodopsins of cetaceans are shiftedfrom red (low energy) to blue (high energy) sensitivity?

The mechanisms underlying the spectraltuning of two of these blue-shifted pigments have recently beenelucidated and depend on three amino acid substitutions(⁸³Asn, ²⁹²Ser, and ²⁹⁹Ser) indolphin rhodopsin, but only one amino acid substitution(³⁰⁸Ser) in the dolphin long-wavelength-sensitivepigment. The objective of this study was to investigate themolecular basis for changes in the spectral sensitivity of rodvisual pigments from seven distantly related marine mammals. Theresults show a relationship between blue-shifted rhodopsins([lambda]_max [less-than-or-equal] 490 nm), deep-divingforaging behavior, and the substitutions ⁸³Asn and²⁹²Ser. Species that forage primarily near the surfacein coastal habitats have a rhodopsin with a [lambda]_maxsimilar to that of terrestrial mammals (500 nm) and possess thesubstitutions ⁸³Asp and ²⁹²Ala, identical torhodopsins from terrestrial mammals.

5. What is the function of the protein ameloblastin?

Is an enamel matrix protein. Theprotein that encodes AMBN gene. Allows growth activity andstructure of the tooth enamel.

Characterize the specific nucleotide sequence and functionaldifferences in ameloblastin genes between baleen whales versusother mammals.

Baleen whale a toothed whale and moredistantly related mammals with single base pair frameshiftinsertion in the baleen whale AMBN pseudogene. Clear cut molecularsignature of a shared signature of shared aquatic ancestry forhippos and whales is currently lacking. Loci related to underwatercision, deep diving and lung surfactant do not show evidence ofmolecular adapation in the common ancestor of these taxa.

6. What are the two main general categories of convergentevolution described in cetaceans and other vertebrates?

Auditory genes. Bats and odontecetshave many similar capabilities with regards to high frequency soundperception.

Selection has driven the independentloss of both OPNI1SQ and OPN1LW in deep diving cetaceans tooptimize visual acuity at depth and at night.

Loss of functional TAS1R genes alsooccurred independently in Otariidae (sea lions) and many carnivorsmammals convergently lack the fuctional sugar taste perception geneTAS1R2

Based on these studies why is it important to use neutral ornearly neutral characters in phylogenetic analyses wheneverpossible?

Comparison amobg a broader taxonomicsample of geneoms can reveal learge suits of genes that haveundergone convergent recruitment and subsittuions among multipleclades of aquatic tetrapods.

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