Chapter 21 Pt. 2 Flashcards
What are the three types of RNA produced in cells?
(1) Messenger RNA (mRNA)
(2) Transfer RNA (tRNA)
(3) Ribosomal RNA (rRNA)
Which type of RNA is this:
carries DNA’s information in the sequence of its bases (condons) from the nucleus to the cytoplasm
Messenger RNA (mRNA)
Which type of RNA is this:
binds to a specific amino acid and transports it to be added, as appropriate, to a growing polypeptide chain
Transfer RNA (tRNA)
Which type of RNA is this:
combines with protein to form ribosomes (structures on which polypeptides are synthesized)
Ribosomal RNA (rRNA)
The process of transcription:
(1)
(2) RNA nucleotides pair with the complementary DNA bases and are linked together to form an RNA transcript
(3) The RNA transcript is released from the DNA
(1) the segment of DNA to be transcribe unwinds
The process of transcription:
1) the segment of DNA to be transcribe unwinds
(2
(3) The RNA transcript is released from the DNA
(2) RNA nucleotides pair with the complementary DNA bases and are linked together to form an RNA transcript
The process of transcription:
(1) the segment of DNA to be transcribe unwinds
(2) RNA nucleotides pair with the complementary DNA bases and are linked together to form an RNA transcript
(3)
(3) The RNA transcript is released from the DNA
________-the signal to start transcription is given by a specific sequence of bases on DNA
promoter
What is an RNA polymerase?
enzyme that binds with the promoter on DNA and then moves along the DNA strand
These unexpressed regions of DNA are called ______, short for __________ ___________
introns
intervening sequences
The remaining segments of DNA or mRNA, called ______ for _________ ___________, splice together to form the sequence that directs the synthesis of a protein
exons
expressed sequences
What is translation?
converts the nucleotide language of mRNA into the amino acid language of a protein
Translation:
____->_______
RNA
Protein
_______ _____-the “language” of genes that translates the sequences of bases in DNA into the specific sequences of amino acids in a protein
genetic code
What are codons?
sequences of three bases on mRNA that specify 1 of the 20 amino acids or the begging or end of the protein chain
The four bases in RNA (A,U,G,C) could form ___ combos of 3-base sequences
64
True or False: the number of possible amino acids, in RNA, exceeds the number of codons
False; the number of possible codons, in RNA , exceeds the number of amino acids
What are the stop codons?
UAA
UAG
UGA
A tRNA molecule must be able to recognize both the ______ on ______ and the ______ _____ that the codon specifies
codon
mRNA
amino acid
How does the tRNA know the correct location along mRNA?
its determined by the anticodon, a sequence of three nucleotides on the tRNA
What is the role of the anticodon?
it “reads” the language of mRNA by binding to a codon on the mRNA molecule according to the complementary base-pairing rules
A ________ consists of 2 subunits (small and large), each composed of ribosomal RNA (rRNA) and protein
ribosome
A ribosome consists of 2 subunits (small and large), each composed of _________ ___ (_____) and ______
ribosomal RNA (rRNA) protein
The subunits, of ribosomes, form in the ________ and are shipped to the _________
nucleus
cytoplasm
What is the role of the ribosome in protein synthesis?
to bring the tRNA bearing an amino acid close enough to the mRNA to interact
What are the three stages of translation?
(1) Initiation
(2) Elongation
(3) Termination
Which stage of translation is this:
the major players in protein synthesis (mRNA, tRNA, and ribosomes) come together
Initiation
Which stage of translation is this:
of the protein occurs a additional amino acids are added to the chain
Elongation
Which stage of translation is this:
occurs when a stop codon moves into the ribosome
Termination
The steps of initiation:
1.
- A tRNA with complementary anticodon pairs with the start codon. Ribosomal subunits join to form a functional ribosome
- the small ribosomal subunit joins to mRNA at the start codon, AUG
The steps of initiation:
1. the small ribosomal subunit joins to mRNA at the start codon, AUG
2.
- A tRNA with complementary anticodon pairs with the start codon. Ribosomal subunits join to form a functional ribosome
The steps of elongation:
- peptide bond formation
- ribosome movement
- codon recognition
The steps of elongation:
- codon recognition
- ribosome movement
- peptide bond formation
The steps of elongation:
1. codon recognition
2. peptide bond formation
3.
- ribosome movement
The steps of termination:
- parts disassemble
- stop codon moves into ribosome
The steps of termination:
1. stop codon moves into ribosome
2.
- parts disassemble
What is a polysome?
a group of ribosomes reading the same mRNA molecule
