AP Bio - Protein Synthesis (Unit 9)

What is the sugar and bases involved in DNA? What is the longetivity and is it double/single stranded?

Deoxyribose sugar, ATGC bases, stable and "immortal", double stranded

What is the sugar and bases involved in RNA? What is the longetivity and is it double/single stranded?

Ribose sugar, AUGC bases, unstable and temporary, single stranded

mRNA (messenger RNA) struc/func

flat, single chain (no secondary structure) directs protein production

tRNA (transfer RNA) struc/func

shaped like a cloverleaf, matches nucleotides in the mRNA with the correct amino acids

rRNA (ribosomal) struc/func

makes up the ribosome, actually catalyzes peptide bond formation

snRNA (small nuclear) struc/func

makes up the spliceosome

DNA codes for ____ through ____ (specific) (even some of this DNA doesn't code for ____, ____ are spliced out)

proteins, mRNA, proteins, introns

Some of the DNA is _____ ____ (promoters, termination sequences, response elements). Some of the DNA codes for tRNA rRNA and snRNA, etc.

regulatory sequences

Genes must be ____ enough and attached to the ______ ____. _______ contain some conserved sequences like the ____ box so that general _____ _____ and ____ polymerase can bind. They also contain unique sequences to each gene so that specific transcription factors can be used to turn on and off genes.

loose, nuclear matrix, promoters, TATA, transcription factors, RNA

An enzyme (_______ ____ _) binds to ______ on DNA at the start of a gene called the __________ (____ box) It copies the ________ strand - It actually starts transcribing after the _____ ___ and moves along the template strand from _' to _'.

RNA polymerase II, transcription factors, promoter, TATA, non-TATA, TATA box, 3, 5

As the ___ _____ _ binds, it opens the ___ and begins to move forward, adding ______ ______. It can only go _ (quantity) direction. It's adding onto the _' end of the growing strand of _____.

RNA polymerase II, DNA, complementary ribonucleotides, 1, 3, mRNA

As the ___ _____ _ moves forward, the ___ re-coils behind it, pushing the single strand of ___ off. This continues until the _____ _____ and even past it for a bit.

RNA polymerase II, DNA, mRNA, termination sequence

In RNA ______, a ___ is added to the front end (_' end) also called methyl guanosine (____ ____ of a guanine), helps ____ leave the _____ and bind to the ____, makes sure it goes in front first and helps it be protected from ____ _____.

processing, cap, 5, modified version, mRNA, nucleus, ribosome, destructive enzymes

_____ tail is added to the ___ of the sequence, keeps important region of ____ from getting ____ up too ___.

Poly-A, end, mRNA, chewed, fast

In _____, _____ are spliced out, while the exons ___ and actually ___ for the ____. This is done by the ______ made of _____.

splicing, introns, stay, code, protein, spliceosome, snRNPs.

How does the ribosome know where to begin translation? What sets the reading frame and what is a reading frame? What is the first thing ALWAYS being translated?

The cap leads the transcript into the ribosome in the right direction, and the start codon (AUG) sets the reading frame (the correct sets of 3 nucleotides). The start codon is always the first thing translated - matches amino acid methionine.

In translation, processed _____ enters the _____ at the ___ and binds to the ____ at the start _____ (AUG) on ___, _______ UAC, amino acid ______, and sets the _____ ____.

mRNA, ribosome, cap, ribosome, codon, mRNA, anti-codon, methionine, reading frame

In the second step of translation, after the reading frame has been set, _____ attaches to ____ codon in the _ site. Then the _____ subunit or ____ binds to ____ subunit and ____. Next tRNA binds to the _____ codon in the _ site.

tRNA, start, P, large, ribosome, small, mRNA, second, A

Once the ____ ___ is ______ bonded to the new _____ ___ in the _ site, the _____ ____ lose their attachment to the _____ in the _ site so both are only attached to the ____ in the _ site. The _____ moves forward, dragging the ____ with it. Finally, the first ___ falls off from the _ site and goes to get a new ___ __ in the cytoplasm.

amino acid, covalently, amino acid, A, amino acid, tRNA, P, tRNA, A, tRNA, mRNA, tRNA, E, amino acid

Once the ____ with the ___ ____ chain has moved from the _ site to the _ site, a new ____ and ____ ___ enters the _ site and a ____ bond forms between the new __ __ and the existing ___ ___ chain. The _____ moves forward again and continues this process until it reaches a ____ codon (___, ___, ___) and the protein itself enters the ___ (usually).

tRNA, amino acid, A, P, tRNA, amino acid, A, peptide, amino acid, amino acid, mRNA, stop, UAA/UAG/UGA, RER

How does the right amino acid get put on the right tRNA that has the correct anticodon?

A group of enzymes called aminoacyl transferase or aminoacyl tRNA synthetase

In post translational modification, _____ enters the ____ ribosome, and as ____ begins, _____ proteins/membrane proteins have a signal peptide at the _____ end. The _____ _____ ____ (___/____) which binds to _____ _____ - takes ____ to ___ and attaches to the growing _____ ___ chain to the __. Then the chain of ____ ___ feeds through a ____ pore into the ___ and a ___ ___ is ____ off.

mRNA, free, translation, secretory, leading, signal recognition particle, RNA/protein, signal peptide, ribosome, RER, amino acid, ER, amino acids, protein, RER, signal peptide, cleaved

Some post translational modifications in the ER include...

aa's can be removed

Lipids, carbs may be added

The chain may be hooked up with another protein to form subunits of a protein with quaternary structure

The chain may be cut into smaller pieces that may hook together

And, of course, folding into its 3D shape

Is the promoter transcribed?

Are the introns transcribed and are they translated? (introns are cut out before the _____ leaves the _____)

Are the 5' and 3' UTR transcribed and are they translated? Where are these regions in relation to the codons?

Is the start codon transcribed and is it translated? Is it cut off in post-translational modifications?

Is the stop codon transcribed and is it translated?

Is the signal peptide transcribed and is it translated? Is it cut out?

Are the poly-A tail and cap transcribed and are they translated? (trick question)

Promoter does not get transcribed

The introns are transcribed but not translated because they are cut out before the mRNA leaves the nucleus

5' and 3' UTR get transcribed but not translated (before and after start and stop codons)

The start codon is transcribed and translated but usually cut off during post translational modifcations

The stop codon is transcribed but not translated

The signal peptide gets transcribed, translated, then cut out

Poly A tail + cap are added - not encoded by DNA