Quiz Questions: Cell Biology: Protein Translation & Transport Lecture

The process in which proteins are transported to the appropriate locations for their functions is called what?? A.) Protein allocation B.) Protein targeting C.) Protein deficiency

B.) Protein targeting

Vanishing white matter (VWM) is a neurological disease that destroys the brains white matter & affects transmission of brain signals to the rest of the body. It is caused by defect in the __________ stage of protein synthesis. A.) Initiation B.) Elongation C.) Termination

A. ) Initiation. Defect in translation initiation factor EIF2B genes is the cause.

True or false. The western blot method is used to measure proteins, and the enzyme-linked immunosorbent assay (ELISA) is used to quantitate proteins by comparing color reaction A.) True B.) False

A.) True

Put the steps of the co-translational translocation protein targeting process in the correct order and choose the corresponding answer choice below. 1.) SRP delivers the ribosome to SRP receptor in the ER 2.) The polypeptide penetrates the ER membrane. The SRP is released and recycled. 3.) Free ribosome synthesize a piece of signal peptide (sequence). 4.) Signal peptidase removes the signal sequence within the ER lumen. 5.) Signal recognition particle (SRP) binds to the signal sequence of the new peptide on the ribosome. 6.) Translation continues until the stop codon. A.) 1,2,3,4,5,6 B.) 3,5,1,2, 4, 6 C.) 5,1,4,3,6,2 D.) 3,5,2,1,4,6

B.) 3,5,1,2, 4, 6 Free ribosome synthesize a piece of signal peptide (sequence). Signal recognition particle (SRP) binds to the signal sequence of the new peptide on the ribosome. SRP delivers the ribosome to SRP receptor in the ER, The polypeptide penetrates the ER membrane. The SRP is released and recycled. Signal peptidase removes the signal sequence within the ER lumen. Translation continues until the stop codon.

Which of the following are not protein chemical modifications in which the addition of a functional group to the protein took place A.) Acylation B.) Deamination C.) Methylation D.) Phosphorylation E.) Glycosylation F.) Lipidation G.) Hydroxylation H.) Disulfide bond formation

B.) Deamination Thats an example of an amino acid modification

Which of the statements regarding Transfer RNA (tRNA) are false? A.) Each tRNA contains about 80 nucleotides B.) Each tRNA has a codon that is complementary to the codon in mRNA C.)tRNA is a molecular adaptor that has an amino acid attachment site and an anticodon that can bind to the codon of mRNA. The anticodon determines what amino acid can be attached to the tRNA.

B.) Each tRNA has a codon that is complementary to the codon in mRNA Because each tRNA has an ANTIcodon, not a codon

True or false. Membrane bound ribosomes make membrane proteins (such as trans-membrane proteins), secretion proteins, and cytosolic proteins. A.) True B.) False.

B.) False. Membrane bound ribosomes do make membrane proteins (such as trans-membrane proteins), secretion proteins, but free ribosomes make proteins that function within the cytosol and used within the cell (cytosolic proteins)

Amino acids, mRNA, ribosomes, the endoplasmic reticulum, and transfer RNA (tRNA) are all used for protein translation. Which of the following statements is false? A.) Amino acids are the material for protein translation. Theyre the building blocks of proteins. B.) mRNA is the vehicle for carrying amino acids (material) for translation C.) Ribosomes are the machinery, the translator D.) Endoplasmic reticulum is the location E.) Transfer RNA (tRNA) is the vehicle for carrying amino acids (material) for translation

B.) mRNA is the vehicle for carrying amino acids (material) for translation mRNA is the coding information (the genetic codons) they provide the blue print.

Protein detection is largely dependent on specific binding of ___________ to proteins A.) Amino acids B.) Antigens C.) Antibodies

C.) Antibodies The anybody is labeled with easy detection molecules (color reaction enzyme, fluorescent molecules)

Where are membrane bound ribosomes located? Free ribosomes? A.) Cytosol, endoplasmic reticulum B.) Nucleus, cytosol C.) Endoplasmic reticulum, cytosol D.) Endoplasmic reticulum, golgi apparatus

C.) Endoplasmic reticulum, cytosol

What is the process of converting the nucleotide sequence of messenger RNA (mRNA) to the amino acid sequence of polypeptide? A.) Protein transcription B.) Protein synthesis C.) Protein translation

C.) Protein translation

There are three major types of protein chemical modifications: Addition of functional groups to the protein, addition of other proteins or peptides, and amino acid modification. Which of the following is an example of an addition of functional groups to the protein? A.) SUMOylation B.) Deamination C.) Ubiquitination D.) Phosphorylation

D.) Phosphorylation

What organelle is responsible for decoding mRNA into polypeptides (translation/protein synthesis) ---the translation machinery? A.) Nucleus B.) Endoplasmic reticulum C.) Golgi apparatus D.) Ribosome

D.) RIbosome

Which of the following statements are true regarding co-translational translocation? A.) Translocation occurs during translation B.) The emerging peptides determine the destinations of the ribosomes C.) If the emerging peptide contains a signal sequence, the ribosome goes to ER for protein synthesis, and the protein will be membrane protein. D.) If the nascent peptide has no signal sequence, the ribosome stays in the cytosol to make cytosolic protein E.) None of the above F.) ALl of the above

F.) All of the above

Which of the following are true regarding facts about genetic codons? A.) Tri-nucleotide bases (Triplet) should be read from 3' to 5' on mRNA without overlapping. B.) 61 codons specify 20 amino acids: the same amino acid may share several codons (no ambiguity), but one codon specifies only one amino acid (redundancy)----Degeneracy of Genetic Code. C.) AGU is the start codon to indicate the site for initiation of the translation, which also encodes the amino acid methionine (Met)*. D.) GUA, UGG, AUG are the stop codons E.) All of the above. F.) None of the above.

F.) None of the above are true. Tri-nucleotide bases (Triplet) should be read from 5' to 3' on mRNA without overlapping. 61 codons specify 20 amino acids: the same amino acid may share several codons (redundancy), but one codon specifies only one amino acid (no ambiguity)----Degeneracy of Genetic Code. AUG is the start codon to indicate the site for initiation of the translation, which also encodes the amino acid methionine (Met)*. UGA, UAA, UAG are the stop codons. (mnemonic: UGA: U Go Away; UAA: U Are Away; UAG: U Are Gone). Stop codons do not code any amino acid.

Which of the following statements are true regarding ribosome structure? A.) A ribosome is made up of two subunits (small subunit: 40S; large subunit: 60S). B.) Each subunit consists of proteins and messenger RNA (35% proteins and 65% mRNA). C.) The two subunits do not bind together when they are not active in protein synthesis (translation). D.) Each ribosome has one mRNA binding site and three tRNA binding sites (A= Aminoacyl-tRNA site, P=Peptidyl-tRNA site, E=Exit site ) E.) All of the above F.) None of the above G.) A, C, D H.) A, B, D

G.) A, C, D B.) is not true because the subunits consist of proteins and RIBOSOMAL RNA not messenger RNA

Translation is divided into three stages: initiation, chain elongation, and chain termination. Which of the following statements occurs in the initiation stage? A.) Binding of the initiator tRNA to the start codon triggers the signals to recruit the large subunit to bind. B.) As the ribosome moves along mRNA (5' to 3'), tRNAs carry amino acids to the ribosome, and amino acids are added to the growing peptide chain. (about 15-50 amino acids /second) C.) when ribosome reaches a stop codon (UAA,UAG or UGA). The releasing factor releases the polypeptide from the ribosome. D.) mRNA 5' Cap recruit the small subunit binding to the mRNA 5' and scanning mRNA for start codon with Kozak sequence. The initiator tRNA carrying Met binds to the start condon. E.)The two subunits of the ribosome dissociate. F.) All of the above G.) None of the above H.) A & D I.) A & B

H.) A & D. B goes with chain elongation and C & E go with termination

Which of the following statements is true regarding the protein targeting process of post-translational translocation A.) These proteins usual contain translocation signal sequences to direct their final transporting locations (nucleus, mitochondria or other cell organelles). B.) The translocation signal sequence is usually at the N-terminal of the protein C.) The translocation signal sequence comes in various sizes; up to 60 amino acids D.) The signal sequence to the nucleus is Ser-Lys-Leu E.) All of the above F.) A & B G.) A & C H.) A, B, C

H.) A, B & C The signal sequence is for peroxisome, not nucleus