Final Pt 1 Flashcards
Life as we know it on earth relies on two fundamental polymers: _____ aka RNA and DNA, and _____ aka proteins. These two compounds are interwoven in ____
polynucleotides, polypeptides, metabolism
A chain of nucleotides linked together by dehydration reactions between the phosphate group of one and the sugar residue of the next
polynucleotides (ex. RNA)
Two polynucleotide strands held together by H bonds between adjacent bases that store the genetic code
DNA
The difference between DNA and RNA are that DNA contains _____ vs _____, ___ vs ___ and is ___ instead of _____ stranded
deoxyribose, ribose, thymine, uracil, double-stranded, single stranded
DNA can be thought of as strings of _____. Units are 3 letter ____ representing a particular __ ___, Ordered succession of codons results in ____
letters, codons, amino acid, proteins
mutations cause ___ within species. Some have __ __, most are ____ and in very rare occasions are ___.
diversity, no effect, detrimental, beneficial
During transcription, only a ___ of one DNA strand is duplicated. ______ carries the information on how to build proteins. ____ have 3 base pairs on one end and at its other end displays a specific sequence of 3 nucleotides (____). In other words, RNA acts as a _____.
section, mRNA, tRNA, anticodon, catalyst
Proteins have the diversity to allow them to perform the various functions necessary to maintain the living organism such as ___, __ ___ and signalling, ____ (enzymes), ______ _____, and _____ actions
structures, molecular recognition, catalysis, molecular transport, mechanical actions
We know that life requires C-based macromolecules such as ___, ___, ___ and ___ ___. The smallest living units of life are __
lipids, carbohydrates, proteins, nucleic acids, cells
Looking at present day biology and extrapolating backwards towards the simplest living entities
top down approach
making the complex building blocks of life (organic macromolecules) and putting them together
bottom up approach
Mycoplasma genitalium has the smallest known genome of free living organisms, with about ___ protein-coding genes and over ____ nucleotide pairs
480, 582,000
Carsonella rudii has the smallest known genone of any living organism with ____ genes and about ___ nucleotide pairs. It is probably missing genes essential for life
182, 160,000
There are corresponding segments of the gene for ____ rRNA (_____ nucleotides, coding for ribosome) for different organisms such as __, ___ and ____. Sites where the nucleotides are identical between species are indicated by a ___ ___. Genetic information has been _____ since the beginnings of life. By looking at the differences in the 165 rRNA we can identify the __ domains of life.
165, 1500, archaea, eukarya, eubacteria, vertical line, conserved, 3
DNA has information to ___ itself but needs proteins to ____ the reaction. Oppositely, proteins can catalyze the reaction but need DNA to ____. It is unlikely that all compounds would from exactly _____ at the same time, so how did they come about
replicate, catalyze, replicate, spontaneously
The RNA world hypothesis is that RNA is an ____ ___ like DNA, and can act as ____ unlike DNA. Thus the DNA/protein world may have evolved from an RNA world
information carrier, catalysts
The problems with the RNA world are in terms of _____, whereby we don’t know how RNA type strings of nucleotides get produced without _____, as well as the ____ problem, where we don’t know how RNA type nucleotides find each other so as to combine into the first RNA type molecules that can _____
energy, life, dilution, replicate
It could be that RNA could form, simple molecules started to form from simpler ______ ____ ___ via ____ cycles. Once these cycles were established, it began to produce ever more ___ compounds. These entities could be subject to a primitive form of ___ eventually giving rise to ___.
metabolically active entities, autocatalytic, complex, selection, RNA
The primordial soup theory is that life began in a warm ____ or ___ from a combination of basic building blocks of life (______ ______), which grew into ever more complex molecules such as ____ and some early versions of ____.
pond, ocean, organic molecules, proteins, RNA
Almost all organic C that we observe today is produced _____ via _____. A ____ gas mixture does not produce organic molecules on its own, so where did these organics come from before there was life?
biologically, photosynthesis, CO2
In the Milley-Urey experiment, it was found that a ___ __ breaks the chemical bonds in ___, ___ and ____. The C, N, H, and O atoms can then recombine into various molecules such as ___, and ____, ___ ___, and other simple ____ molecules that eventually end up in the ___.
spark discharge, CH4, NH3, H2O, HCN, H2CO, amino acids, organic, ocean
There is debate over the presence of large amounts of __ and ___ in the early atmosphere as used in the Miller-urey experiment. Additionally, in a ____ rich atmosphere, organic production by spark discharge is not very ____. If the ___/____ ratio is less than ___, there is essentially no organic production. If an atmosphere is dominated by CO2, the most abundant radical after spark discharge or ____ is ___. The products would be __, __, __ and ___.
NH3, CH4, CO2, efficient, CH4/CO2, 0.1, photolysis, O, NO, CO, NO2, H2O
Organic molecules could have also been produced in hydrothermal vents, as they were likely to be present in the ____ _____. Organic synthesis requires only ___, ___, __ ___ and heat, and occurs through ______ or ___ _____.
prebiotic environment, CO2, H2O, silicate rocks, serpentinization, spinel polymerization
Its also possible that organics were ___ and brought from ____. About _____% of chondrites are ____ which contain ___ ____, ____ and ____. However, these were not a good source of organic compounds. The native chondrite supported ___ ___, while the ___ chondrite was inhibitory and resulted in a decline of microbial cell concentration. ____ ____ particles provided a constant, ____ ___ of organic compounds to the surface of the earth.
synthesized, space, 5, carbonaceous, amino acids, hydrocarbons, fullerenes, microbial growth, pyrolyzed, interplanetary dust, steady flux
The problem with extraterrestrial organic delivery is that they could only provide ____ organics, no large ____. Similarly, it is hard to accumulate necessary ___ of carbon for the concentrated ___ ____. Additionally, most organic matter is physically ____ ___ to be taken up directly by heterotrophic microorganisms. Consequently, many heterotrophs secrete _____ that break down large molecules outside the cell into smaller molecules.
simple, macromolecules, mass, prebiotic soup, too big, exoenzymes
Phosphorous is a very ____ element in the universe. On earth it is found as ___ ___ ____, which are not readily taken up and usually are not found in ____. The ratio of C:N:P in modern marine biomass typically showed limited variation around the canonical redfield ratio, which is ____C:___N: ___P
rare, insoluble phosphate minerals, water, 106, 16, 1
Phosphorous plays essential roles in phosphate groups in ___ and ____, ____, and ____.
DNA, RNA, ATP, phospholipids
Meteorites contain two forms of phosphorous, ____ and _____. The latter rusts in the presence of water to form a __ and ___ P.
apatite, schreibersite, soluble, reactive
Phoshorylation, which is the addition of a ___ group, it vital for the cellular storage and ___ of ____ ___ using energy carrier molecules.
PO3, transfer, free energy
ATP, the most abundant energy carrier molecule, has two high energy ____ bonds that can be broken to release free energy or vice versa added to ___ to store it as ___ energy for later use. We find that in general, ____, ___ and ___ are N poor and P rich compared with nearby stars. However, the dearth of P abundance data, which exists for only ___% of all stars and ___% of exoplanet hosts, makes it difficult to deduce clear trends in the stellar data let alone the role of P in the evolution of an exoplanet
phosphate-phosphate, ADP, chemical, plankton, earth, mars, 1, 1
