8.4 Transcription
What does the central dogma for modern biology state?
information flows in one direction, from DNA to RNA to proteins
What is RNA?
Ribonucleic acid--A chain of nucleotides made of sugar, a phosphate and nitrogen base ( temporary copy of DNA that is used and then destroyed)
What three processes are part of the Central Dogma?
1. Replication 2. Transcription 3. Translation
Three significant ways RNA differs from DNA
1. Sugar in RNA is ribose- has 1 additional oxygen atom) 2. RNA has the base uracil in place of thymine (still bonds with adenine) 3. RNA is a single strand of nucleotides
What is Transfer RNA (tRNA)
Bring amino acids from the cytoplasm to the ribosomes to help make proteins
What is Transcription
Converts DNA message into RNA
What is Replication
Copies DNA
In eukaryotic cells, where does replication, transcription, and translation take place? Why?
Replication and transcription occur in the nucleus, while translation occurs in the cytoplasm. Reason: DNA is located inside the nuclear membrane- processes separated both in location and time.
What is Translation
Interprets the message from RNA into a string of amino acids that form proteins
What are the three RNA molecules produced by transcription?
Messenger RNA, Ribosomal RNA, and Transfer RNA
What is the third step of Transcription?
RNA detaches from the DNA and transcription is complete
What is transcription catalyzed by?
RNA polymerase (enzymes that bond nucleotides together in a chain to make a new RNA molecule.
What is the first step of transcription?
RNA polymerase and other proteins recognizes the start site of a gene and the DNA strands begin to unwind
What is the second step of Transcription?
RNA polymerase uses one strand of DNA as a template to produce a complimentary strand of RNA (Remember A-U in RNA)
What is Messenger RNA (mRNA)
Takes the DNA message for conversion to protein
What is Transcription?
The process of copying a sequence of DNA to produce a complimentary strand of RNA *** a gene, not an entire chromosome- is transferred into an RNA message
What does RNA work as?
an intermediate link between DNA and protein synthesis
What is Ribosomal RNA (rRNA)
forms parts of ribosomes
In prokaryotic cells, where does replication, transcription, and translation take place?
the cytoplasm at approximately the same time.