1What is the link between genotypes and phenotypes?
Proteins
2What are the differences between RNA and DNA
RNA has a sugar ribose base instead of deoxyribose, Thymine is replaced by Uracil, RNA is single stranded as compared to double stranded DNA.
3What role does a single DNA strand play in the process of transcription?
DNA strand serves as a template for the synthesis of a complementary RNA strand, a mRNA is transcribed from the template strand of DNA.
4What is mRNA and its function?
Messenger RNA, Transcript of protein-building instructions.
5Where does transcription and translation occur in Prokaryotic cells?
Cytoplasm for both processes
6What is the molecular chain of command?
DNA-RNA-Protein
7Where does transcription and translation occur in Eukaryotic cells?
Transcription occurs in the nucleus and translation occurs in ribosomes of the cytoplasm.
8What occurs in Translation?
The order of nucleotides in mRNA is used to determine the amino acid sequence of a polypeptide. This process occurs in the ribosomes.
9What are the stages of Transcription
Initiation, Elongation, Termination
10What kinds of RNA can you synthesize from a starting DNA template
mRNA, tRNA, rRNA
11What is the first stage of gene expression?
Transcription
12Terminator
Signals the end of transcription
13RNA polymerase function?
Separates the DNA strands and synthesizes the RNA according to base pair rules.
14Start and Stop codons are associated with what part of RNA replication
Translation
15What is the ONLY end RNA polymerase can add nucleotides to?
3' end
16RNA polymerase can start transcribing a mRNA without a primer, true or false?
True
17What is a promoter?
Specific sequence of nucleotides along the DNA mark
18Promoter and Terminator is associated with what part of RNA replication? Where are they located?
Transcription, DNA.
19What determines which strand of the DNA helix is the template?
The promoter sequence
20Where is the starting point of transcription?
Within the promoter
21Transcription factor proteins are exclusive to what?
Eukaryotes
22Describe how transcription occurs for eukaryotes
Proteins called transcription factors will bind to the promoter region and RNA polymerase will bind to the transcription factors creating a transcription initiation complex. RNA polymerase will then start transcription.
23Explain the process of transcription
As RNA polymerase moves along the DNA, it untwists the double helix. The enzyme adds nucleotides to the 3' end of the growing strand. Before RNA synthesis the double helix reforms and the RNA molecule peels away.
24What must happen for the process of transcription to end?
The RNA polymerase must transcribe a terminator sequence in the DNA.
25What is the polyadenylation signal? Function?
Polymerase synthesizes the code, proteins bind the signal and 10-35 nucleotides past the signal the proteins release the transcript from RNA polymerase.
26Nucleus modify the pre-mRNA before it enters where?
Cytoplasm
27What is added to the pre-mRNA as protection?
A modified form of guanine is added to the 5' end
28At the 3' end what is added?
Enzyme adds 50 to 250 adenine nucleotides forming a poly (A) tail. This protects against hydrolysis.
29RNA splicing?
Removal of large portion of mRNA
30What are introns?
long noncoding stretches of nucleotides, lie between coding regions.
31What is the promoter in RNA replication?
The promoter is a specific sequence of DNA nucleotides that specifies other molecules where transcription can begin. (TATA box).
32What sequence of amino acids signal for translation to begin?
AUG
33Describe translation...
Translation occurs in the ribosome when mRNA moves from the nucleus to the cytoplasm. In the ribsomes there is tRNA with anticodons that base pair with the mRNA codons which then add the correct amino acid to the growing polypeptide chain.
34What is the function of RNA polymerase in RNA replication?
RNA polymerase unwinds DNA double helix structure and synthesizes an RNA strand based on DNA template strand.
35What is a codon in RNA replication?
A codon is a block of 3 nucleotides that code for a sequence of amino acids
36How many total codon codes are there? How many code for amino acids?
64, 61
37What binds to the promoter (TATA box) and what does it form?
Transcription factors, transcription initiation complex
38What does P site hold?
Holds the tRNA carrying the growing polypeptide chain
39What does A site hold?
tRNA with the next amino acid
40What site are discharged tRNAS held/dismissed?
E site