Protein Synthesis Nas 2 quiz 16

What happens to tRNA molecules after they add their amino acid to the growing protein chain? a) They are released from the mRNA to pick up the specific amino acid coded for by their anticodons. b) They degrade, and the RNA nucleotides are recycled. c) They pick up new amino acids, whichever one is closest in the cytoplasm.

a

Each codon of mRNA (hence each triplet in DNA) codes for one:

amino acid

The specific amino acid carried by a tRNA is determined it's:

anticodon

a set of three nucleotides on the tRNA that is complementary to an mRNA codon.

anticodon

RNA's to all the following except.... a) carry amino acids to ribosomes b) hold the cell together c) speed up cellular process d) switch cellular machinery on and off e) carry coded messages from the nucleus to the ribosome

b

the coded regions that are expressed sequences

extrons

Both the guanine cap (5') and a poly-A tail (3') help to......

protect strand from hydrolytic enzymes, attach to ribosome, and release RNA into cytoplasm

True or False? The same amino acid can be carried by different tRNA'S.

true

True or False? Whenever a cell needs to, it can unzip DNA and make a transcript of a sequence so that a protein can be made. DNA then zips up.

true

If a DNA sequence consists of 12 nucleotides, how many mRNA codons will there be?

4

What is the correct order of assembly in the cellular factory?

DNA - RNA - protein

The enzyme that creates mRNA from a DNA sequence is called:

RNA polymerase

What is transcription catalyzed by?

RNA polymerase

Which step comes first in protein synthesis?

Transcription

Which of the following best describes the process of translation? a) Anticodons on the mRNA molecule indicate the correct sequence of amino acids. b) Codons on the mRNA molecule are read by a ribosome. c) tRNA molecules bind to DNA in order to link amino acids in the correct order.

b

Ribosomes need mRNA and tRNA to help complete translation. Which statement correctly describes their roles? a) tRNA builds the ribosome, while mRNA translates the nucleus into a protein b) mRNA helps the tRNA translate the ribosome into a protein c) tRNA translates the code in the mRNA into a string of amino acids d) Ribosomes build tRNAs, which are translated into mRNA messages.

c

Which of the following descriptions of transcription is INCORRECT? a) Only certain genes (not the entire DNA strand) are transcribed at a given time. b) Only one strand of DNA is transcribed. c) The new mRNA strand elongates in the 3' to 5' direction.

c

a sequence of three nucleotides that codes for a specific amino acid.

codon

Translation is the second step of Protein Synthesis and it occurs in the:

cytoplasm

Where does the cell transcription take place in prokaryotes?

cytoplasm

True or False? When amino acids are brought in by tRNA, they are joined together by hydrolysis reactions to form the growing protein.

false

Name the three steps of transcription in order.

initiation, elongation, termination

noncoding regions of DNA or RNA

introns

Transcription is the first step of Protein Synthesis and it occurs in the:

nucleus

This RNA carry a protein building block (an amino acid) to a cell's protein assembly machine, called a ribosome. And translates the genetic code of messenger RNA (mRNA) into the amino acid sequence of proteins. What type of RNA is this?

tRNA

Which RNA carries amino acids to the ribosome during translation? mRNA (messenger RNA) rRNA (ribosomal RNA) tRNA (transfer RNA)

tRNA

_____________________ converts a gene into a single-stranded molecule.

transcription

What are the two steps of protein synthesis?

transcription and translation

________________________ converts an mRNA message into a polypeptide, or protein.

translation