Chapter 10- Molecular Biology Of The Gene Flashcards
What is the difference between purine and pyrimidine?
Purines have two rings: A + G, and pyrimidines have one: C, T
What is Chargoff’s rule?
Purine must match with a pyrimidine.
What are the steps in DNA replication?
- DNA unwinds and unzips
- DNA polymerase adds complimentary bases
- Ligase seals the Okazaki fragments together
What is semiconservative replication
One old strand and one new strand is used
What is helicase and what does it do?
A protein and unwinds and unzips the double helix by breaking the hydrogen bond between A = T and G =_ C
What is DNA polymerase and what does it do?
A protein that adds complimentary bases to the 3’ end of the DNA, polymerizes nucleotides (–> nucleic acids), and proofreads new strand of DNA
What is ligase?
A protein that seals the Okazaki fragments together
What is the difference between leading and lagging strands?
Leading strands are continuous and lagging strands are broken down into fragments (Okazaki) and have to jump back to the start to continue the strand
What is transcription?
Copying a section of DNA into RNA
What are the steps to transcription?
- Initiation: RNA polymerase binds to the DNA at the TATA box and separates the double helix
- Elongation: RNA polymerase joins together RNA nucleotides (A, G, C, U) using one DNA strand as a template
- Termination: RNA polymerase stops at a terminator sequence
Transcript the following DNA strand:
TATACCGATC
AUAUGGCUAG
What is translation?
Decoding mRNA into proteins
What are the differences between DNA and RNA?
The pentose of RNA is ribose, and the pentose of DNA is deoxyribose. RNA is single stranded, and DNA is double stranded. For one RNA’s four bases, uracil replaces thymine.
What are the steps in post transcriptional processing?
- Cut out introns and join leftover exons
2. Add cap and tail
What are the different types of RNA? What are the their functions?
- mRNA - messenger
- rRNA - ribosomal
- tRNA - transfer