test 2 Flashcards
molecular components of DNA
adenine, cytosine, guanine, thymine; deoxyribose (pentose) is the phosphate background (sugar)
molecular components of RNA
adenine, cytosine, guanine, uracil; ribose (pentose) is the phosphate background (sugar)
nucleotide
base+sugar+phosphate= nucleotide
how can nucleotides be measured
by distance and length
DNA and RNA strands
nucleotide+ nucleotide(n)= strand
deoxyribonucleotides; ribonucleotides
DNA
double stranded; double helix; hydrogen bonds enable the ladder and hold the helix together, bonds can be broken; one sequence predicts the next one; complex macromolecules made of several basic atomic components; encodes genes
DNA hierarchical arrangement
dna from each parent arranged into chromosomes (23 chromosomes from each) 22 pairs of autosomes and 1 pair of sex chromosomes
replication
process through which DNA serves as the template for the synthesis of RNA
transcription
process through which DNA serves as the template for the synthesis of RNA
what causes bonds to break
increase in temperature and pH
DNA replication
relies on complementary base pairing ; occurs before mitosis and meiosis 1; semi conservative; DNA is synthesized by DNA polymerase in a 5’ to 3’ direction
what is DNA polymerase responsible for
synthesizing a new strand of DNA during replication
helicase
surrounds and separates enzyme
where are the genes
indicated by start (ATG) and stop (TAA, TGA, TAG) codones; hold the code for specific protein
transcription
relies on base pairing; RNA is synthesized by RNA polymerase 2
RNA processing in eukaryotic cells
splicing out of introns, capping with 5’ methyl cap, polyadenylation
translation
ribosomes make proteins from the messages encoded in mRNA; three nucleotide groups called codons encode one amino acid (genetic code)
genetic code
each 3-nucleotide mRNA codon specifies a particular amino acid; each tRNA transfer a particular amino acid
mRNA
template for the production of proteins, the molecules that build and comprise structures and perform enzymatic reactions
tRNA
enables the transfer of amino acids into a growing polypeptide chain
rRNA
a component of protein producing ribosomes
the chromosome
each in a living cell is a DNA double helix; in the cell nuclei of higher organisms usually linear (larger, complex); some of bacteria are circular
*gene, nucleotide, genome, chromosome (smallest to largest)