Chapter 7 Protein synthesis NEW

What is 1st key difference between DNA and RNA?

RNA is generally single stranded where DNA is double stranded

What is the 2nd key difference between DNA and RNA?

RNA has an –OH group on the 2’ carbon and DNA has an –H

What is the 3rd key difference between DNA and RNA?

RNA contains the base uracil (U) instead of thymine (T)

What are the 3 different major types of RNA?

• mRNA (messenger RNA)

• rRNA (ribosomal RNA)

• tRNA (transfer RNA)

What is the monomer of proteins?

Amino acids

What is a gene?

segment of DNA, codes for particular proteins

What is transcription?

The process of making mRNA from DNA

What is translation?

The process of making protein from RNA

What is the 1st step in making proteins?

mRNA is created in the nucleus through the process of transcription

What is the 2nd step in making proteins?

mRNA is transported out of the nucleus to a ribosomes which uses the mRNA as a template to make a particular protein through the process of translation

Where does transcription occur?

In the nucleus of the cell where DNA is stored

What indicates where a gene starts?

Small section of DNA called a promoter

What is DNA polymerase used for?

used to make new DNA strands

What is RNA polymerase used for?

used to make mRNA

What’s step one in transcription initiation?

RNA polymerase binds to a sequence of DNA called a promoter found near beginning of the gene

What’s step two in transcription initiation?

RNA polymerase unwinds DNA strand once it finds the promoter

What’s step one in transcription elongation?

One strand of DNA acts as a template for RNA polymerase (template strand)

What’s step two in transcription elongation?

RNA polymerase creates new mRNA in the 5’ to 3’ direction using the complemetary bases to the template strand

What is transcription termination?

Sequences signal in the DNA that the RNA strand is complete

What are the bases of amino acids if doing DNA replication

A = T, C = G

What are the bases of amino acids if doing transcription

A = U, C = G

What are the 3 post-transcriptional modifications?

• Splicing

• 5’ cap

• 3’ Poly-Adenine tail

What are exons?

segments of the pre-mRNA that are used to create or code for the protein (the vital parts of the recipe)

What are introns?

a segment of the pre-mRNA that does not code for proteins and interrupts the sequence of genes

What is splicing?

process of removing all the unneeded introns from a pre-mRNA strand and then splicing together all the needed exons into mature (finalized) mRNA strand

What is the process of splicing a pre-mRNA strand called?

spliceosomes

What is protein 5’ cap do?

Will prevent the destruction of the mRNA by proteins exonucleases in the cell cytoplasm

What is a poly-adenine tail added by?

poly(A) polymerase

What does a poly-adenine tail do?

serves to protect the mRNA from exonucleases in the cytoplasm which would destroy it otherwise

What is a ribosome?

made of rRNA and is composed of a large and small subunit

What is the role of a ribosome?

link chains of amino acids together to form a specific protein by reading the mRNA

What is the 1st step in translation?

once the mRNA is ready, it leaves the nucleus and finds a ribosome which will “read” the mRNA strand from the nucleus

What is the 2nd step in translation?

creates a specific protein from that recipe by putting together the correct amino acids

What is a 3 unit code referred to as?

A codon

What amino acid appears at the beginning of every protein?

Met

What are 3 codons that do not code for amino acids?

UAA, UAG, UGA

What is translation initiation?

Ribosomal subunit binds to the start codon

What is step 1 in translation elongation?

mRNA feeds through the ribosome (rRNA) in between the large subunit and the small subunit

tRNA in protein synthesis part 1

ENTERS in the A site there the ribosome checks to see if the anticodon on the tRNA is a compliment

tRNA in protein synthesis part 2

If the tRNA is the correct one, it shifts over to the P site where it is given the growing chain of amino acids by the previous tRNA and shifts to the E site

tRNA in protein synthesis part 3

The tRNA hands over the growing amino acid chain to the next tRNA before it EXITS out of the E site

Translation - termination

Stop codons code for a special tRNA holding a Release Factor instead of an amino acid

Finished proteins part 1

Once the proteins are made, they then get sent to the Endoplasmic Reticulum

Finished proteins part 2

The Endoplasmic Reticulum folds the proteins into their final shape and places them in temporary vesicles to be sent to the Golgi Body

Finished proteins part 3

The Golgi Body repackages the finished protein and sends it where it needs to go

Where do you find the anticodon?

On tRNA

Where do you find the codon?

mRNA

Viruses are not able to what?

Reproduce on their own

What do viruses need to help reproduce?

A host cell

Immune system is made up of what cells?

White blood cells and antibodies

What do white blood cells do?

Destroy invaders that threaten the body (ex. bacteria and viruses)

What is adaptive immunity?

The faster you recognize the virus/bacteria as a threat, the less time it has to replicate and potentially harm you

What is live attenuated vaccines?

Takes an infectious agent and alter its DNA, although still alive, it becomes harmless or less deadly

What is Inactivated vaccines

When Individuals are given only fragments of virus encouraging immune system to create antibodies without individual actually getting sick

1st method on how vaccines saves lives

Keeping healthy individuals from contracting serious disease that could hurt or kill individual

2nd method on how vaccines saves lives

Keeping individuals who cannot take vaccine healthy by not exposing them to serious diseases in others

The most modern vaccines are?

Inactivated vaccines

Inactivated vaccines are?

highly efficient with a very low risk

What does a traditional vaccine do?

Try to replicate spike-proteins and introduce them to human immune system

Step 1 on how mRNA vaccines work

Vaccine contains mRNA blueprints rather than viral proteins themselves

Step 2 on how mRNA vaccines work

Cells take viral mRNA and produce viral spike proteins in large amount through translation

Step 3 on how mRNA vaccines work

Our immune system now has a large amount of viral proteins it is being exposed to

Step 4 on how mRNA vaccines work

If the immune system sees the viral proteins again (the person is exposed to the virus), it can quickly destroy the virus without the person getting sick

How are traditional vaccines produced?

Take many years to create as they mass produce a small amount of the virus protein needed