DNA MIDTERMS - TRANSCRIPTION

central dogma of life

DNA Replication - Transcription - Translation

what is transcription

DNA to mRNA

where does transcription happens?

nucleus

what is translation

mRNA to proteins

where does translation happens?

cytoplasm (ribosomes)

expression of genes: why are some genes transcribe in large quantities?

need large amount of this protein

expression of genes: why are some genes transcribe in small quantities?

need less amount of this protein

DNA’s code must be copied and taken to the?

cytoplasm

The process of copying the sequence of one strand of DNA, from the template strand

Transcription

what are the 2 strands of DNA?

template and coding strand

this strand is being copied by the RNA to make mRNA

template strand

Polymerase needed for transcription?

RNA Polymerase

this strand contains the code that is needed to make protein

coding strand

this strand is non-informational strand and is useless for protein making

template strand

Why do we make the RNA out of the template strand?

complements the template strand and is identical to the coding strand

3 kinds of Polymerases

Polymerase 1: catalyze rRNA

Polymerase 2: catalyze mRNA

Polymerase 3: catalyze tRNA

carries information for a specific protein?

Messenger RNA (mRNA)

RNA Polymerase must be able to recognize both the _____ and ______ of genes in order to _____ and ______

beginnings and ends to initiate and terminate transcription

what does RNA polymerase 2 do?

create mRNA

why is it important to recognize the correct DNA strand?

to avoid transcribing the DNA strand that is not informational

Toward the 5’ end of the coding strand

Negative (-) Upstream

Toward the 3’ end of the coding strand

Positive (+) Downstream

The DNA region that RNA polymerase associates with immediately before beginning transcription

Promoter Region (where the RNA Polymerase attaches itself)

Regions of DNA at the beginning of genes with signals that allow RNA polymerase to attach and begin transcription

Promoters

a seven base sequence, located at about -25 on the promoter DNA 

TATA Box (Hogness Box)

if the RNA Polymerase sees this from our DNA, mag attach ang RNA Polymerase and mag start na ang mRNA 

TATA Box (Hogness Box)

OTHER PROMOTERS THAT DOES NOT HAVE TATA BOX HAVE THESE:

Initiator Element and Downstream Promoter Element (TATA less promoter regions)

2 types of Promoter Regions?

1. TATA Box (Hogness Box)

2. Initiator Element with Downstream Promoter Element (TATA Less)

Factors that influence which codes we want to transcribe more and transcribe less

Transcription Factors

for basal rate of transcription

General TFs

for high level of transcription (activated transcription)

Specific TFs (Activators)

To attach at the beginnings of genes, RNA Polymerase 2 must interact with several proteins called?

General Transcription Factors (Protein)

TFIID: is composed of:

• TATA-binding protein (TBP)

• TBP- associated factors (TAFs)

help RNA Polymerase to locate the Promoter Regions 

Transcription Factors

process of starting the transcription

Preinitiation Complex (PIC)

activates RNA Polymerase 2 and acts as the Helicase and separates the DNA Base code (separates the coding and template strand)  

TFIIH

Needed for activated transcription

activators

allows to transcribe more

activator

Opposite with Activator

Repressors

Opposite ng Enhancers 

Silencers

2 MAJOR PARTS OF EUKARYOTIC GENE

1. Structural Gene (transcribed into RNA)

2. Regulatory Gene (controls the transcription)

made of exons and introns

Structural Gene

To start transcription, what should attach to the promoter region?

RNA Polymerase

what helps the RNA Polymerase locate the Promoter Region?

Transcription Factors

We need RNA Polymerase to attach to the Promoter Region

Initiation

what happens during initiation phase

1. split DNA

2. RNA Polymerase to located Promoter Region

3. Once located, RNA polymerase will be activated

Creating of the mRNA out of the template strand 

Elongation

this happens during elongation

Allow the RNA Polymerase to do its work and make more mRNA 

If walang ____process, RNA Polymerase will make the mRNA out of the entire DNA

Termination

When the polymerase enzyme recognizes this DNA region, termination of transcription comes about 

Termination

initial and unprocessed mRNA

Primary Transcript

2 methods used to process primary transcripts

1. RNA Capping (5’ end)

2. Polyadenylation (poly-A tail)

RNA Processing Main Function

help increase the stability of the mRNA

what to add at the end of the 5’ prime in RNA capping?

methyl guanosine triphosphate

used as a recognitional signal for ribosomes

5’ prime cap

purpose of the RNA Capping (5’ end)

protect the DNA for our ribosomes to recognize the mRNA

what helps our mRNA attach to the Ribosomes

RNA Caps (methyl guanosine triphosphate)

this can be seen in 3’ prime (Polyadenylation)

Adenosine Nucleotides

adenosine nucleotide is added by what enzyme?

poly-A polymerase

introns removed, exons reconnected

splicing

2 types of splicing

1. self splicing

2. protein mediated splicing

exons, segments of DNA that code for proteins, are then rejoined by the

enzyme ligase

What carries the code in order for specific amino acids to be synthesized and grow into protein?

mRNA

If the newly made RNA is a messenger RNA, what type or RNA Polymerase is present?

RNA Polymerase 2

The DNA strand that is not informational also known as?

Template Strand

The TATA box is located 25 base pairs. Upstream or Downstream?

Upstream (-25)

Where does RNA Polymerase 2 attach to start the transcription process?

Promoter Region: TATA Box or if TATA Less: Initiator Element with Downstream Promoter Element

What recognizes the promoter region and guides the RNA Polymerase there?

General Transcription Factors

What allows the bending of our DNA during transcription?

TFIID: if it bends it promotes transcription

What causes significant bending and opening of the DNA during transcription?

TFIID or TBP (TATA Binding Protein)

For activated transcription to take place, activators must bind with what?

Enhancers

When the RNA polymerase reaches the DNA’s termination sequence, what do you call the product that is released from the process?

Primary Transcript

What is the purpose of the RNA cap?

To increase the stability of mRNA and for the ribosomes to recognize our mRNA

The poly-A tail is made up of what type of nucleotides?

Adenosine Phosphate Nucleotides

Splicome and ribozymes remove which part of the primary transcript?

Introns

. What are the major processes that happen to the primary transcript in RNA processing?

RNA Capping

Polyadenylation

Splicing