4_DNA Structure, Analysis, and Sequence

What are the four characteristics that a genetic material must exhibit?

Replication, Storage of Information, Expression of Information, Variation by mutation

Some cells do not allow mutations; some cells allow mutation.

Variation by mutation

In 1868, he isolated cell nuclei and derived an acid substance containing DNA that the called nuclein.

Friedrich Miescher

In 1910, he observed that DNA contains approximately equal amounts of four similar molecules called nucleotides – the tetranucleotide hypothesis.

Phoebus A. Levene

What is the hypothesis wherein DNA contains approximately equal amounts of four similar molecules called nucleotides

tetranucleotide hypothesis

In the 1940s, he showed that Levene’s proposal was incorrect when he demonstrated that most organisms do not contain precisely equal proportions of the four nucleotides.

Erwin Chargaff

What did Erwin Chargaff argue?

more guanine and cytosine

In 1944, these people published the chemical nature of a “transforming principle” in bacteria was the initial event that led to the acceptance of DNA as the genetic material.

Oswald Avery, Colin MacLeod, Maclyn MacCarty’s

When DNA is removed, this get lost

virulence

In 1953, who discovered the double helix structure of DNA?

James Watson and Francis Crick

It is a long, ladder-like macromolecule that twists to form a double helix.

DNA

Each linear strand of the helix is made up of subunits called what?

nucleotides

What are the four different nucleotides?

Adenine, Guanine, Thymine, Cytosine

The four different nucleotide each contains what?

nitrogenous base

What is the complementary pair of thymine?

adenine

What is the complementary pair of guanine?

cytosine

This is considered the backbone of molecular biology

central dogma

What part of the central dogma where the DNA replicates its information in a process that involves many enzymes?

replication

The DNA codes for the production of messenger RNA (mRNA) during what phase of the central dogma?

transcription

In eukaryotes, how is the mRNA processed?

splicing

These carries coded information to ribosomes.

messenger RNA

This is a part of the central dogma where ribosomes “read” this information and use it for protein synthesis.

translation

These involved in almost all biological activities, structural or enzymatic.

proteins

Type of Protein that functions as a catalyst

enzymatic

Type of Protein that functions as a support

structural

Type of Protein wherein examples are casein and proteins in seeds

storage

Type of Protein wherein examples are hemoglobin and carrier proteins

transport

Type of Protein that functions for coordination

hormonal

Type of Protein that functions as a response

receptor

Type of Protein that functions for movement

contractile and motor proteins

Type of Protein that functions for protection against diseases

defensive

What are the three essential components of a DNA?

nitrogenous base, pentose sugar, phosphate group

A type of nucleic acid that has one ring. Cytosine, uracil and thymine falls under this type.

pyrimidines

A type of nucleic acid that has two ring. Adenine and guanine falls under this type.

purines

This tells us that the nitrogenous base and sugar

nucleoside

This is a nucleoside with phosphate group

nucleotide

In sugars, the attachment of the nucleoside base will always be at what carbon?

Carbon 1

The attachment of the phosphate group can be found at what carbon?

Carbon 5

Nucleotide linkage follow what direction?

5’ to 3’`

We add nucleotides at the 3’ with the free hydroxyl group using what type of bond?

phosphodiester bond

One complete turn of DNA

34A

Major groove can be found where in DNA?

22A

It is defined as doubling the DNA content.

DNA replication

DNA is reproduced by what type of replication?

Semisconservative Replication

What type genetic material can be found in prokaryotes?

circular and smaller

What type genetic material can be found in eukaryotes?

straight

Where can genetic material be found in prokaryotes?

cytoplasm

Where can genetic material be found in eukaryotes?

nucleus

He tracked replication in E.coli, using radioactive precursors of DNA synthesis and autoradiography.

John Cairns

It is the single region of E. coli where replication is initiated.

oriC

This creates two replication forks that migrate farther and farther apart as replication proceeds

bidirectional replication

The forks in bidirectional replication eventually merge, as semiconservative replication of the entire chromosome is completed, at a termination region called?

ter

In 1957, he isolated an enzyme from E. coli that was able to direct DNA synthesis in a cell-free (in-vitro) system.

Arthur Kornberg

What is the enzyme that Arthur Kornberg isolated from E. coli?

DNA polymerase I

What are the two major requirements for in vitro DNA synthesis under the direction of DNA polymerase I?

four dNTPs, template DNA

This is considered a property of Bacterial DNA polymerase, also known as proofreading activity

Exonuclease activity

These enzyme are capable of performing replication.

DNA Pol III holoenzyme

It is where the lagging strand forms a loop, allowing the lagging strand to catch up with the leading strand.

concurrent DNA synthesis

This cuts DNA tor release tension

DNA gyrase

This process is synthesized on a DNA template, catalyzed by DNA-dependent RNA polymerase.

transcription

These are required for transcription

ATP, GTP, CTP, UTP, Mg2+

Yes or No? Is RNA primer required in transcription?

No

In transcription, the RNA chain is synthesized in what direction?

 5’ to 3’

This contains signals for initiation and termination of RNA synthesis.

DNA base sequence

The enzyme binds to and moves along the DNA template in what direction?

3’ to 5’

What signals the RNA polymerase to start?

AUG

Also called the noncoding strand

template DNA

Where does prokaryotic transcription occurs?

cytoplasm

Where does eukaryotic transcription occurs?

nucleus

In prokaryotes, does transcription and translation happens simultaneously?

Yes

Transcription and translation differ in space and time, prokaryotes or eukaryotes?

eukaryotes

Prokaryotes or Eukaryotes: mRNA is transcribed directly from template DNA molecule

prokaryotes

Prokaryotes or Eukaryotes: initially a pre-mRNA molecule is formed and then processed to yield a mature mRNA

eukaryotes

In prokaryotes, how many subunits does the RNA polymerase have?

5 subunits

In eukaryotes, how many subunits does the RNA polymerase have?

10-17 subunits

Prokaryotes or Eukaryotes: holoenzyme recognizes and binds directly to the promoter

prokaryotes

Prokaryotes or Eukaryotes: promoter recognition cannot be carried out by RNA polymerase alone

eukaryotes

What are the darker-colored and thicker lines here?

exons

What are the lines in here?

introns

Can the DNA be coded on both sides or strands?

yes

If there is no promoter, there is no what?

expression

If promoter is for transcription, primer is for what?

replication

What are the two chromatin states?

euchromatin and heterochromatin

In prokaryotes, what is the transcription product?

mRNA or transcripts

This looks for the promoter and forms a complex with the polymerase

Sigma factor

This is found at the downstream or end part of the gene

termination

What are the codons for termination in mRNA?

UAG, UGA, UAA

What are the codons for termination in template DNA?

ATC, ACT, ATT

What is the promoter sequence for eukaryotes?

TATA box

What is the promoter sequence for prokaryotes?

Pribnow box

This type of termination is when the rho factor catches with the RNA polymerase, it helps the RNA polymerase detach.

Rho-Dependent Termination

A type of termination where the DNA has a small bump and inverted repeats, and no rho factor is needed.

Rho-Independent Termination

This is a characteristic of only RNA molecules

hairpin loop

What is the 2nd repeat sequence in rho-independent termination?

polyA

What is the 2nd repeat sequence in rho-independent termination on mRNA?

polyU

You can isolate mRNA by using the tail of what primer?

polyT

This is also called the -10 element (TATAAT) or -35 element (TTGACA)

Pribnow Box

This is the basic core promoter of eukaryotes within 50bp upstream of the start site

TATA box

This protein emits fluorescent light that helps trace seeds carrying GOI.

GFP

This potentially causes cancer to plants.

Agrobacterium