CPA #11 Questions Flashcards
define: 5 prime
the 5’ end terminates in a phosphate group attached to a 5’ carbon
define: 3 prime
the 3’ end terminates with a hydroxyl group bound to a 3’ carbon of deoxyribose
define: antiparallel
one strand runs 5’-3’ and the other strand runs 3’-5’
define: plasmids
- small molecules of DNA that replicate separate from chromosomes
- 1%-20% the size of a chromosome
- not essential for normal metabolism, growth, or cellular respiration
what are the 4 types of plasmids?
- fertility plasmids
- resistance plasmids
- bacteriocin plasmids
- virulence plasmids
define: fertility plasmids
carry instructions for conjugation; the transfer if DNA to other bacterial cells
define: resistance (R) plasmids
carry genes for resistance to one or more antimicrobial drugs or heavy metals
define: bacteriocin plasmids
carry genes for proteinaceous toxins called bacteriocins (kill bacterial cells of the same species that lack the plasmids)
define: virulence plasmids
carry instructions for structures, enzymes, or toxins that enable a bacterium to become pathogenic.
explain how eukaryotic genomes consist of both nuclear and extranuclear DNA
eukaryotes also have mitochondria (or chloroplasts) which are outside of the nucleus and they contain chromosomes.
define: histones
positively charged; stabilize and package DNA.
define: nucleosomes
negatively charged DNA wraps around a positively charged histone protein to form a 10-nm-diameter bead
define: chromatin fibers
nucelosomes clump with other proteins; dispersed throughout the nucleus
define: euchromatin
active DNA; loosely packed chromatin fibers
define: heterochromatin
inactive DNA; tightly packed chromatin fibers
explain how DNA replication is an anabolic polymerization process
adding nucleotides to the end
define: genotype
actual set of genes inside genome; consists of all the series of DNA nucleotides that carry instructions for an organisms life
define: phenotype
refers to the physical features and functional traits of an organism (structure, function, morphology)
define: RNA primer
molecules for DNA polymerase to use during DNA replication
define: mRNA
messenger; carry genetic info from chromosomes to ribosomes
define: rRNA
ribosomal; combine with ribosomal polypeptides to form ribosomes (organelles that synthesize polypeptides)
define: tRNA
transfer; which deliver the correct amino acids to ribosomes based on the sequence of nucleotides in mRNA
how is mRNA processed before translation?
- undergoes polyadenylation
- ribosomes remove introns and splice together exons
- forms a molecule that codes for a single polypeptide
how is DNA replication semiconservative?
take old strand and rip it open (creating two separate strands) and act as a template to build a new complementary strand to match (two new complementary strands)
summarize the process of transcription
- initiation of transcription
- elongation of RNA transcript
- termination of transcription (release RNA polymerase by one of 2 methods)
what are the 2 ways to terminate transcription?
- self-termination
- Rho-dependent termination
summarize DNA replication
- Initial process
- synthesis of leading strand (continuous)
- synthesis of lagging strand (discontinuous)
define initial process (DNA)
cell removes proteins from the DNA molecule; helicase unzips double helix
define: continuous synthesis (leading strand)
synthesis toward the replication fork (5’ toward 3’)
define: discontinuous synthesis (lagging strand)
synthesis away from the replication fork (3’ toward 5’)
