Module 10 - 4 Flashcards
(33 cards)
What are the primary enzymes for synthesizing nucleic acids?
DNA and RNA polymerases
What are the substrates for nucleic acid synthesis?
Nucleotide triphosphates
In what direction do all polymerases synthesize nucleic acids?
5’ to 3’
Where are incoming residues added during nucleic acid synthesis?
3’ end of the growing strand
What is the criteria for selecting incoming residues during nucleic acid synthesis?
Complimentary to the template strand
What is Polymerase Chain Reaction (PCR)?
Amplification of short regions of DNA
What does PCR take the advantage of?
the ability for each DNA strand to serve as a template for production of a complimentary
How is new DNA made through PCR?
Heat stable enzymes
What did PCR revolutionize?
Molecular biology, and diagnostics, and forensics
DNA in eukaryotes need to be packaged into what?
Higher order structure due to the amount
What is the first level of DNA packaging in eukaryotes?
Formation of nucleosomes
What are nucleosome beads?
DNA histone complexes on a string of double stranded DNA
What are nucleosomes?
structural unit for packaging chromatin; consisting of a DNA strand around a histone core
What are histones?
DNA packaging proteins
Characteristics of histones?
Highly conserved and positively charged
What are the five histone proteins?
H1, H2A, H2B, H3, and H4
What is the composition of a nucleosome?
Two molecules of each H2A, H2B, H3, H4 and 146 base pairs of DNA
What is the role of H1 in a nucleosome?
Binds the region of linker DNA
How are histones modified to regulate their interaction with DNA?
Reversibly modified
What is a gene?
Segment of DNA containing information for production of a biological product
How can the size of a gene be estimated?
From the size of the corresponding protein
What is the relationship between nucleotides, codons, and amino acids?
3 nucleotides = 1 codon = 1 amino acid
Where are genes contained?
Within chromosomes
How many chromosomes do viruses and bacteria have?
Single chromosome