Biochem Exam 4 Nucleic Acids

consume, anabolic

De novo pathways that synthesize nucleotides_____ ATP< so they would be labeled

initiation

Flavanols are plant-derived compounds that bind and disable helicase DnaB. Exposing prokaryotes to flavanols would interfere with which stage of DNA synthesis / replication?

We have the gene in our genome, but it isn't expressed.

Humans lack a functional uricase gene. What does that mean?

carbon skeletons

On exam 3, multiple students wrote: "The keto acids could use glycerol as a fuel source." This sentence is factually incorrect because keto acids are:

it is able to make the primer on its own, you do not need another helicase for transcription; RNA polymerase is able to separate two strands on its own

Prokaryotic RNA polymerase has "intrinsic helicase activity". What does that mean?

False

Prokaryotes do not have DNA

termination

Quinolones are antibiotics that bind and disable type II topoisomerases. Administering this drug would interfere with which stage of prokaryotic DNA synthesis / replication?

DNA; positively-charged

Chromatin involves wrapping <blank1> around <blank2> histones

proteome

complete set of proteins that is constantly changing

Genome

complete set of proteins that is static and unchanging

gene

physical and functional units of inheritance that DNA contains that is stored in nuclei or nucleoid

DNA polymerase

enzyme that catalyzes phosphodiester formation in DNA; connecting one deoxyribose to another, has to have a primer and metal cation charge

topoisomerase

enzyme that cleaves DNA to adjust negative supercoils, Type I cuts one strand and Type II cuts both strands

DERA

enzyme that cleaves deoxyribose sugar in deoxyribose metabolism which generates acetaldehyde and glyceraldehyde 3-phosphate. mainly expressed in liver, lungs, and colon (large intestine)

ligase

enzyme that joins two DNA fragments together via ATP hydrolysis

helicase

enzyme that separates double helix via ATP hydrolysis; allows DNA polymerase to get access to deoxyribonucleic acid

primase

enzyme that synthesizes short segments of RNA (primers), makes initial starting point for DNA replication

exonuclease

enzymes that cleave at the end of the nucleic acid chain

endonuclease

enzymes that cleave within nucleic acid chain

nucleoside

it is a 5-carbon sugar, a nitrogenous base, and no phosphate groups

gene copy number

it is when long or short sections of the genome is repeated, varies by individual, the more gene copies, the more receptors, then increased detection

enhancer

regulatory DNA sequence that is a transcription factor binding site, that causes DNA to bend to bring enhancer closer to promoter, helps recruit RNA polymerase to the gene, may be upstream or downstream of gene, must be on same chromosome,

silencer

regulatory DNA sequence where a transcription factor can bind, interferes with transcription and gene expression, may bend DNA

DNA replication would occur multiple times per cell cycle; transcription would be suppressed.

Ubiquitination is a form of post-translational modification used to regulate both DNA replication and transcription. What would happen when both licensing factor proteins and histones are ubiquitinated?

an intermediate for the citric acid cycle

You work in a lab that created a new pyrimidine. Based on your knowledge of biochemistry, metabolizing this nitrogenous base would generate:

No, she is not correct. The brain continues to perform glycolysis because her body is obtaining glucose via gluconeogenesis. The brain and body still need glucose, and the glucose demand for the brain is so high. The liver uses the glucogenic AAs from the protein in her diet as non-carbohydrate precursors. The glucose synthesize in the liver is sent to the brain, which then brings it across the blood-brain-barrier using abundant and diverse glucose transporters. Once the glucose is in the brin cell, it is metabolized via cellular respiration which includes glycolysis.

Your friend is on the keto diet, in which she eats high-protein, low-carb meals. She tells you that she chose this diet so her body doesn't have to metabolize sugars via glycolysis anymore. Is she correct? Explain your logic in 2-3 sentences, focusing on the brain, its energy demands, and the transporters present in the blood-brain-barrier. How is her body obtaining glucose?

No, you shouldn't take DNA supplements because the body doesn't store excess nitrogenous bases

Your friend, who eats a vegetarian diet, tells you that she is concerned her body is deficient in dietary nucleic acids. She is thinking of taking DNA supplements to increase her body's cache (stored supply) of nitrogenous bases. What would you tell her?

shorter, wider A form

Adding ethanol to a test tube containing DNA will alter the nucleic acid's conformational state. Since ethanol (C2H6O) competes with DNA to form hydrogen bonds with water, you would expect the DNA in the test tube to be in the:

granulated sugar

All the following foods contain DNA except:

cytoplasmic plasmids

Antibiotic resistance genes are generally found on ____ in prokaryotes.

BOTH

Are humans ingesting eukaryotic nucleic acid, prokaryotic nucleic acid, or both?

Yes, they are considered true polymers. It is a large biomolecule, it passes our average protein in size. It has multiple monomers and it is interlinked, a nucleotide is directly connected to another nucleotide.

Are nucleic acids considered "true polymers"? Explain why or why not.

ribose: second carbon has an hydroxyl (OH) group deoxyribose: second carbon is a hydrogen atom purines: two fused aromatic rings pyrimidines: single aromatic ring

Be able to identify ribose and deoxyribose sugars. Be able to identify purine and pyrimidine nitrogenous bases.

ribose: glycolysis or gluconeogenesis deoxyribose: glycolysis nitrogenous bases: citric acid cycle for pyrimidines; glucose: glycolysis keto acids from glucogenic AAs: pyruvate oxidation or citric acid cycle keto acids from ketogenic AAs: citric acid cycle glycerol: glycolysis fatty acids: CAC ketone body: CAC

Be able to identify the metabolic entry point(s) (i.e., glycolysis, pyruvate oxidation, and/or the citric acid cycle) for the following carbon fuels: ribose, deoxyribose, nitrogenous bases, glucose, keto acids from glucogenic AAs, keto acids from ketogenic AAs, glycerol, fatty acids, and a ketone body. [Hint: Review relevant Lipid, Protein, & Carb PPTs]

False

DNA replication and transcription are interdependent processes, meaning one doesn't occur without the other.

Telomeres: repetitive regions of non-coding nucleotides at the ends of chromosomes so if they get cleaved it is okay. They protect DNA against exonucleases and from shortening during replication. No there are no telomeres on prokaryotic chromosomes because they are circular (no end or beginning)

Define telomere. Are telomeres present on prokaryotic chromosomes?

True

Deoxyribonucleotides are synthesized from ribonucleotides

NAD+

Deoxyribose metabolism generates acetaldehyde, which gut microbes can further process via alcoholic fermentation. Based on what you know about fermentation, alcoholic fermentation would likely regenerate <blank> for glycolysis.

False

Dietary nitrogenous bases are stored for later use.

No it does not happen all the time, it happens during cell division

Do cells perform DNA synthesis constantly? If not, when does DNA replication occur?

No

Do nucleotides enter cellular respiration intact?

It recycles more purines: 70%

Does the human body salvage / recycle a greater percentage of pyrimidines or purines?

NO, they are independent pathways

Does transcription require DNA replication?

pepsin cleaves phosphodiester bridges in the nucleic acid

During digestion in the stomach, what happens to dietary sources of nucleic acids?

nucleic acids and proteins

During digestion, pepsin cleaves covalent bonds within which biomolecules?

it is able to make the primer itself, it can synthesize RNA based primer

Eukaryotic DNA polymerase α has "intrinsic primase activity". What does that mean?

It is a mechanism to generate diverse proteins. There is an initial mRNA template , and you do not have to translate all exons in alternative splicing, it will take certain ones to form certain proteins. It can retain and remove others through splicing; depending on which exons we keep and translate we get different proteins

Explain how the process of alternative splicing works.

It is metabolized in the citric acid cycle

Fumarate is generated during the course of purine de novo synthesis. Based on your knowledge of biochemistry, what happens to this major metabolic intermediate?

glycolysis

G3P can enter cellular respiration as an intermediate of

DNA

Genes are made of

are not, glycolysis

Glucose (C6H12O6) and ribose (C5H10O5) ______ isomers. Ribose will generate intermediates for _________ in cellular respiration.

Proteins and nucleic acids are both denatured by the acidic environment and pepsin cleaves both of these biomolecules into fragments. The noncovalent interactions in both biomolecules are disrupted. Pepsin randomly cleaves both protein and nucleoprotein particles.

How are digestive activities in the stomach similar for proteins and nucleic acids? [Hint: Review Protein 5 PPT]

They are both nucleic acid. They both are made up of a phosphate group, carbon sugar and nitrogenous bases. They have the same purines: adenine and guanine. They both have strand directionality. They are both pentose sugars. Their pyrimidines differ as DNA as cytosine and thymine and RNA has cytosine and uracil. RNA is usually a single strand and DNA is usually a double helix structure. RNA is hydroxyl group attached to 2-carbon and DNA has hydrogen atom attached to 2-carbon.

How do DNA and RNA differ? How are they similar?

DNA polymerase: requires a primer, corrects errors during proofreading, in eukaryotes, DNA polymerase has primase activity RNA polymerase: in prokaryotes, this polymerase has helicase activity, there is little proofreading, does not correct errors, can generate different transcribed products, uses a promoter similar: both added nucleotides to the 3' end of the newly synthesized strand, both catalyzed phosphodiester bridge formation, both has intrinsic helicase activity at some point

How do DNA polymerase and RNA polymerase differ? How are they similar?

In eukaryotic, DNA polymerase has primase activity, we terminate by replication fork collisions, and there is mitochondria-specific DNA-binding proteins How do nuclear DNA replication and mitochondrial DNA replication differ? Mitochondria needs its own set of DNA replication machinery. It has DNA polymerase a, helicase TWINKLE and primase POLRMT, it is unidirectional process. There are no Okazaki fragments generated, it is only a leading strand. and it needs SSB proteins to stabilize parental H strand until second ori reached.

How does eukaryotic replication differ from prokaryotic replication?

In eukaryotes, 1. termination strategy differs by polymerase a. there are three different polymerase 2. abundance of enhancer sequences a. more than prokaryotes 3. formation of transcription initiation complex a. eukaryotes RNA polymerase require multiple transcription factors to bind to promoter 4. RNA product further processed/edited a. all primary RNA transcripts are further processed that involves intron removal

How does eukaryotic transcription differ from prokaryotic transcription?

DNA replication and transcription both occur in the nucleus and translation happens at the endoplasmic reticulum. It separates the central dogma in physical location and in time. There will be a delay because you are having to transport mRNA from nucleus to endoplasmic reticulum to translate it into a protein.

How does the nucleus impact the central dogma in eukaryotes?

No, they are not guaranteed to develop the condition/disease because the gene may not be expressed. However, if there are changes in default gene expression level, that could develop the disease.

If someone has a gene associated with a genetic disorder, is he/she guaranteed to develop the condition / disease? Why or why not?

An irreversible inhibitor forms a stable bond with the enzyme and permanently inactivates it. Telomerase synthesizes and maintains telomeres. Telomeres protect the ends of DNA from exonucleases. If telomerase was not working, there would be no maintenance of the telomeres. With cell aging, telomeres shorten and limit proliferation. The telomere would quickly shorten which would speed up cell aging. Cancer cells have a limitless replicative potential. Imetelstat would reverse this have the cancer cells have telomere shortening very quickly hoping to approach cell death and stop replicating sooner.

Imetelstat is a broad-spectrum anti-cancer drug and an irreversible inhibitor of telomerase. In 2-3 sentences, discuss the impact (if any) Imetelstat would have on eukaryotic: DNA replication, transcription, and cell aging. Be sure to define the term "irreversible inhibitor" in your response.

False

In an aqueous environment, DNA is more susceptible to hydrolysis than RNA is.

False

In eukaryotes, messenger RNA is synthesized (via transcription) at the same time it is translated into protein.

bidirectional , unidirectional

In eukaryotes, nuclear DNA replication is _____, while transcription is

Yes, this condition would impact both pyrimidine and purine ribonucleotide synthesis

Individuals with congenital glutamine deficiency do not synthesize sufficient quantities of the enzyme glutamine synthetase. Consequently, concentrations of glutamine remain low in the liver and plasma. Would this condition impact ribonucleotide de novo synthesis?

nucleotide

It is a 5-carbon sugar, a nitrogenous base, and 1-3 phosphate groups

DNA is found within foods that contain cells like fruits, vegetables, meats, etc. Inorganic food additives like salt or baking soda lack DNA

Know some examples of edible items that contain nucleic acids and some that don't.

pyrimidine: yields B-alanine and B-aminnoisobutyrate ammonia and CO2 B-alanine converted into malonyl CoA or excreted in urine Malonyl CoA is an intermediate of fatty acid synthesis Can also be converted into acetyl CoA and enter citric acid cycle B-aminnoisobutyrate converted into succinyl CoA or excreted in the urine Succinyl CoA is an intermediate of citric acid cycle purine: yields uric acid uric acid sent to the kidneys via bloodstream then excreted in urine if plasma level are higher, it can precipitate about and deposits into joints Final products from either pathway can be excreted from body in urine

Know the final products from purine and pyrimidine nitrogenous base metabolism. What happens to each of them?

carbon, hydrogen, nitrogen, oxygen, phosphorus

Know the major elements required for life present in nucleotides

There is based-catalyzed deprotonation which leads to nucleophilic attack on adjacent phosphorus. We ionize part of H2O, deprotonate hydroxyl that is attached to 2' carbon on ribose which breaks ester bond and further break apart unstable intermediate/ Deoxyribose is less susceptible to hydrolysis because it is hard to deprotonate hydrogen atom the same way we deprotonate OH in the RNA ribose group

Know why susceptibility to hydrolysis differs between DNA and RNA.

in glycolysis

Metabolizing a deoxyribose sugar via the pentose phosphate pathway generates glyceraldehyde 3-phosphate. What would glyceraldehyde 3-phosphate enter cellular respiration?

False

Nucleotides enter cellular respiration intact

TTF-1

RNA products of stop signal is a TTF-1 binding site, with polymerase I, nascent RNA contains TTF-1 protein binding site, it cause polymerase to stall and dissociate

Pyrimidine metabolism generates two products which are converted into intermediates of the citric acid cycle which generates 2 ATP. Purine metabolism generates one product which is oxidized to form uric acid which is then excreted into the urine, this generates no ATP. Therefore, eggs generate more ATP than sardines.

Sardines are considered a high-purine food, while eggs are considered a high-pyrimidine food. Based on what you know about biochemistry, which food (sardines or eggs) would you expect to generate more ATP? Explain your logic in 2-3 sentences, discussing the products generated from nitrogenous base metabolism and cellular respiration.

Severely damaged cells have broken membranes, which allows the histones to leak out and enter the circulatory system.

Severe trauma can result in sepsis (or blood poisoning), a life-threatening medical emergency. One way doctors can diagnose sepsis is with blood tests. For example, increased levels of circulating histones are associated with multiple organ failure. What do you think is the most logical explanation for this correlation?

Both cytoplasmic proteins and plasma membrane

The hydrophobic effect stabilizes DNA's structure. What other cellular component relied on the hydrophobic effect for structure?

lipid: glycolysis protein: amino acid metabolism carb: gluconeogenesis

The liver is an essential organ, responsible for many complex processes, like the pentose phosphate pathway. For each of the prior biomolecule sections (i.e., lipids, proteins, and carbohydrates), know 1 relevant metabolic pathway we discussed that occurs in the liver. [Hint: Review relevant Lipid, Protein & Carb PPTs].

True

The majority of DNA is non-coding

does not require or involve ATP

The pentose phosphate pathway is unusual because it

the oxidative phase of the pentose phosphate pathway

The protein complex mTOR (Links to an external site.) promotes cell proliferation by funneling glucose 6-phosphate from glycolysis into the pentose phosphate pathway. Individuals with advanced pancreatic cancer are often prescribed Everolimus because this drug attaches to a protein required by mTOR, thereby inhibiting mTOR enzyme activity. Consequently, Everolimus suppresses:

True

Tus is an example of a DNA-binding protein.

It begins with minimal degradation in the mouth because saliva does not contain nucleic acid specific digestive enzymes. In the stomach, nucleic acids are denatured by the acidic environment and pepsin cleaves nucleic acid into fragments. Pancreatic enzymes continuing cleaving fragments in the small intestine. Nucleosidases and phosphatases cleave monomers into components. Enzymes attached to external surface of intestinal cells; components transported into intestinal cells then released into the blood No, nitrogenous bases are not stored in the body. They are either used as building blocks for new nucleic acids or if not needed, metabolized.

Understand how dietary nucleic acids are digested. Are dietary nitrogenous bases stored in the body?

a. It is regulated via molecules involved in DNA synthesis (replication). i. You can phosphorylation primase in prokaryotes or DNA polymerase a in eukaryotes. You can also ubiquitination or acetylate licensing factor proteins. b. It is regulated via molecules involved in RNA synthesis (transcription). i. Phosphorylation of RNA polymerase ii. Binding of transcription factors iii. Presence of lipid-derived hormones iv. Histone or DNA modification

Understand how nucleic acid synthesis regulated.

Prokaryotes store DNA on a singular circular chromosome, which is attached to plasma membrane at midpoint for cell division. Bacteria also may have plasmids which rarely contain essential genes. Prokaryotes compact their DNA via supercoiling and are normally negatively supercoiled. Eukaryotes store DNA across multiple pairs of linear chromosomes and these different chromosomes contain different essential genes. In eukaryotes DNA is compacted be being wrapped around histones and then formed into a nucleosome bead which is then formed into chromatin.

Understand how prokaryotic and eukaryotic chromosomes differ.

For pyrimidines, aspartate transcarbamoylase (ATCase) and carbamoyl phosphate synthetase II (CPSII) are both key enzymes ATP is a stimulator of ATCase and CPSII CTP is an inhibitor by feedback inhibition of ATCase For CPS II PRPP and ATP are stimulators and UTP is an inhibitor using feedback inhibition For purines, the key enzyme is glutamine phosphoribosyl aminotransferase (GPAT) GPAT is inhibited by IMP, AMP, and GMP through feedback inhibition and stimulated by ATP also regulated at IMP branch point: IMP is inhibited by AMP through feedback inhibition and inhibited by GMP through feedback inhibition because if we already have enough, we do not need to be making more. For deoxyribonucleotides, regulation involves two allosteric sites: an activity on/off site and a substrate specificity site. ATP stimulates and dATP inhibits.

Understand how ribonucleotide synthesis (both purine and pyrimidine) and deoxyribonucleotide synthesis are regulated.

It may prevent nucleic acid synthesis (via stalling of polymerase and/or replication fork) or result in daughter strands with different sequences. It may induce cell transformation, spread/metastasis, and/or cell death. it can also lead to metabolic dysfunction

Understand why DNA damage is a concern.

Lipid-derived hormones can easily diffuse through the plasma membrane. Since they are lipophilic, they can access receptors in the nucleus and turn on nuclear hormone receptors. The receptor binds to DNA and the hormone and initiates positive or negative loop and hormone is required for receptors to alter gene expression.

Understand why nuclear hormone receptors (and their lipid primary messengers) can be used to alter gene expression. [Hint: Review Lipid 2 PPT]

Both have strand directionality

What do DNA and RNA have in common?

Both involve removing nitrogen via deamination or transamination

What do amino acid metabolism and nitrogenous base metabolism have in common?

Both can be bound by transcription factors

What do enhancers and silencers have in common?

both hydrolyze ATP to power their reactions

What do helicase and ligase have in common?

Both are unidirectional processes

What do mitochondrial DNA replication and prokaryotic transcription have in common?

Both require a prime and a DNA polymerase

What do prokaryotic DNA replication and mitochondrial DNA replication have in common?

Both pathways build ring structures using amino acids

What do pyrimidine de novo synthesis and purine de novo synthesis have in common?

Both involve deaminations that generates NH4+

What do pyrimidine metabolism and purine metabolism have in common?

It is the phenomenon by which nonpolar molecules aggregate to avoid contact with polar molecules, particularly water. It helps stabilize DNA. Nonpolar nitrogenous bases in the interior of the double helix stabilized by Van der Waals interactions with base pairs above and below, hydrogen bonds between complementary base pairs and Polar phosphate groups on the exterior stabilized by hydrogen bond with surrounding water.

What is the hydrophobic effect? How does it impact nucleic acids?

It is unusual because no ATP is produced or used Nitrogenous base metabolism occurs in the mitochondria in the liver in humans, highest activity of pentose phosphate pathway is in the liver, adipose tissue and red blood cells

What is unusual about the pentose phosphate pathway? Does this pathway occur in the same location as nitrogenous base metabolism?

acetylate histones

What modifications could be used to increase gene expression in eukaryotes?

pentose phosphate pathway; From ribonucleotides; ribose sugar reduced to deoxyribose sugar by ribonucleotide reductase

What pathway synthesizes ribose? How is deoxyribose made?

True

When we eat food, we are consuming non-human DNA

major groove

Which DNA groove is more accessible to DNA-binding proteins?

high concentrations of ATP

Which environmental signal stimulates both CPSII and ATCase in pyrimidine de novo synthesis?

a. Histones a. Increase: acetylation and phosphorylation b. Decrease: ubiquitination b. DNA modification a. increase: b. decrease: DNA methylation via DNA methyltransferases

Which histone modifications would increase versus decrease gene expression? What about DNA modifications?

UTP: cytosine or thymine IMP: adenine or guanine

Which nucleotides can be made from UTP? Which nucleotides can be made from IMP?

single-strand binding protein, Tus protein, ligase, RNA polymerase, transcription factor, telomerase

Which of the following are DNA-binding proteins?

single-strand break

Which type of DNA damage occurs most often (i.e., has the highest # per cell per day)?

DNA is circled in water molecules. Water helps stabilize the DNA structure by binding to each phosphate group. Every phosphate group has a water molecules. When dehydration happens. water has to share multiple phosphate groups causing it to become smaller and wider.

Why does dehydration cause DNA's conformational state to change?

Tus protein

acts as a counter helicase: holds two strands together, holds double helix, prevents separation into two complimentary strands; causes replication fork to stall in prokaryotic DNA synthesis termination

hydrogen bond

bond found between complementary base pairs in DNA

ester linkage

bond found between nucleotides in RNA

euchromatin

chromatin that is less compacted; more frequently transcribed; this is what majority of human genome is

heterochromatin

chromatin that is more compacted; less frequently transcribed

DNA polymerase y

copies mitochondrial DNA

DNA polymerase s

copies nuclear DNA

deoxyribonuclease

pancreatic enzyme that cleaves DNA in the small intestine

intron

do not encode for proteins, normally removed out

essential gene

genes that are required for survival; often involved in basic metabolic functions

genotype

genetic information for a trait

surface charge

help stabilize DNA; negative charged phosphodiester bridges helps repel nucleophiles and allows for tight binding with positively-charged histones

Epigenetics

heritable changes in gene expression due to environmental factors, it creates differences in phenotype not genotype

essential genes are primarily stored on bacterial chromosomes, not bacterial plasmids

how do bacterial chromosomes differ from bacterial plasmids?

activated nucleotide

in the triphosphate form

topoisomerase type 2

introduces double-strand breaks

topoisomerase type 1

introduces single strand breaks

Junk DNA

introns are historically labeled this

Rho factor

involved in prokaryotic RNA synthesis termination, it is an RNA-binding protein that causes RNA polymerase to dissociate, when Rho factor is involved the stop signal product is a binding site for Rho factor, it will bind to the RNA and climb up the RNA until it encounters RNA polymerase and knocks it off DNA template

RNA polymerase:

key DNA-binding protein; enzyme that catalyzes phosphodiester brides formation in RNA, in prokaryotes, this polymerase also has helicase activity sigma subunit: responsible for locating the promotor in prokaryotic RNA synthesis initiation

ribozyme

natural non-protein enzyme; RNA molecules that cleave or ligate nucleic acid, mimic catalytic mechanism of topoisomerase or ligase, DNA binding proteins

ribonuclease

pancreatic enzyme that cleaves RNA in the small intestine

phenotype

observable appearance of a trait

telomerase

polymerase that synthesizes and maintains telomeres

glucose 6-phosphate

primarily pulled from glycolysis for pentose phosphate pathway; starting material for oxidative phase of pentose phosphate pathway for ribose synthesis

transcription factor

regulatory DNA-binding protein; may also bind ligands, the larger the genome the more transcription factors, some activate transcription (bind to promoter's upstream region and recruit RNA polymerase) and some suppress transcription (bind to promote and interfere with RNA polymerase's access to start site

operon

regulatory system in which multiple functionally-related genes are controlled by a single promoter; all genes must be expressed together, present mainly in prokaryotes

depurination

removing purine nitrogenous bases, type of DNA damage that happens to about 10,000 cells a day

extron

section of DNA that encodes for proteins

plasmids

smaller DNA molecules that are not required to live; bacteria may have then, it rarely contains essential genes, readily gained or lost, antibiotic resistance genes are frequently found here

single-strand binding protein

stabilizes DNA and prevents annealing by binding to newly separate double helix

ribulose 5-phosphate

the end product of converting glucose 6-phosphate through oxidation, hydrolysis and oxidative decarboxylation, it is then isomerized and cyclized to form nucleotide sugar (ribose)

polymerase switching

trading one polymerase for another during transition from initiation to elongation; DNA polymerase a starts then dissociates and another either s or e completes replication

PRPP

what is needed for pyrimidine and purine de novo synthesis; activated sugar Semiconservative replication

ribose 5-phosphate

what ribose gets transformed into to be funneled into pentose phosphate pathway