Protein Structure and Translation

Question 1

Transcription occurs in the

Answer 1

Nucleus

Question 2

Primary Structure (Protein)

Answer 2

Amino Acid chain and order

Question 3

Amino Acid

Answer 3

20 different kinds incorporated into proteins, and it has to be incorporated into a protein to be considered an amino acid.

Question 4

Secondary Structure (Protein)

Answer 4

Results from interactions in nearby amino acids.
A-helices and B pleated sheets

Question 5

Tertiary Structure (Protein)

Answer 5

3-dimensional shape of a polypeptide, hydrophobic and hydrophilic interactions, H-bonding, Disulfide bridges.

Question 6

Quaternary Structure (Protein)

Answer 6

Results from interactions of polypeptide subunits.

Question 7

Special Amino Acids

Answer 7

Glycine, Proline, Cysteine

Question 8

Glycine

Answer 8

Allows for rotation

Question 9

Proline

Answer 9

Allows for rigidity

Question 10

Cysteine

Answer 10

SH groups cause disulfide bonding, hold 3-dimensional shape

Question 11

Peptide bond

Answer 11

Formed by dehydration synthesis, links carboxyl end to the amine end

Question 12

Alpha Helix

Answer 12

Each carboyl group in the backbone forms an H-bond with an amine group four residues away.

Question 13

Beta Pleated Sheet

Answer 13

Adjacent strands can run in the same direction or in opposite. Hydrogen bonds form between carbonyl groups in one polypeptide and amide groups in a different part of the polypeptide.

Question 14

Aminoacyl tRNA synthetases

Answer 14

Charge tRNA with the correct amino acid

Question 15

Ribosome structure

Answer 15

Large subunit and small subunit. Large subunit has the exit site, the peptidyl site, and the aminoacyl site.

Question 16

Reading Frame

Answer 16

Determined by ribosomes, when mRNA is read in groups of three.

Question 17

tRNA structure

Answer 17

DHU loop, anticodon loop, T(psi)C loop, amino acid attachment site

Question 18

Components of Translation

Answer 18

Initiation, Elongation and Release factors. Aminoacyl tRNA synthetases, tRNA, Ribosome, mRNA

Question 19

Marshall Nirenberg

Answer 19

Credited with coming up with the genetic code and explaining how it works in protein synthesis.

Question 20

Wobble Effect

Answer 20

Third position of a codon can sometimes change out and the same amino acid will still exist and be placed in the correct spot

Question 21

Translation Process

Answer 21

Initiation is at the 5’ cap and AUG is the start codon. Initiation factors recruit the small ribosomal subunit and tRNA(met) and scan the mRNA far AUG. Initiation factors are released and a tRNA complimentary to the next codon binds to the A-site. A reaction transfers the Met to the amino acid on the tRNA in the A-site forming a peptide bond. The now uncharged tRNA is moved into the E site and the tRNA(val) moves into the PP site, and a new tRNA binds to the A site. Bond connecting polypeptide to the tRNA breaks after stop codon causes termination. Release factor binds to the A site.

Question 22

Initiation in Prokaryotes

Answer 22

Located at any Shine-Dalgarno sequence; therefore the mRNA produced is polycystronic- can code for multiple polypeptides. Prokaryotes can have multiple proteins being made at once.

Question 23

Shine-Dalgarno Sequence

Answer 23

Occurs before the start codon, and signals for the initiation of translation.

Question 24

Post-translational Modifications

Answer 24

Addition of glucose, phosphate lipids, carbs
Addition of an acetyl or methyl group
Cleave off a piece of the peptide.

Question 25

Initiation

Answer 25

initiation factors recruit the small subunit of the ribosome along with a charged tRNA that codes for Methionine. The start codon is AUG and the anticodon found on the tRNA is UAC. When the start codon is found the large subunit comes and the mRNA transcript is now ready to be read properly now that we know the reading frame

Question 26

Elongation

Answer 26

The tRNA for methionine moves from the A site to the P site, where the amino acid forms a peptide bond with the incoming amino acid. Methionine tRNA moves down one more to the E site known as the Exit site where it leaves

Question 27

Termination

Answer 27

When a stop codon is encountered, a protein release factor binds to the A site, breaking the bond between the polypeptide chain and the tRNA of the last amino acid, creating a C terminus of the polypeptide chain

Question 28

Proteins are listed from the ____ end to the ____ end

Answer 28

Amino, Carboxyl