STRUCTURE AND FUNCTION OF THE GENETIC MATERIAL Flashcards
Lesson 3
building blocks of DNA and RNA
Nucleotide
the inherited genetic material inside each cell
deoxyribonucleic acid (DNA)
______ acid; relays instructions from the genes to guide each cell’s synthesis of proteins from amino acidS
ribonucleic acid (RNA)
a segment of a DNA (or RNA) molecule that determines the traits and control protein synthesis; discrete unit of heredity
Gene
total genetic information carried in a cell or an organism
Genome
the science of heredity
Genetics
the sequencing and molecular characterization of genomes
Genomics
- Bacteria have a single circular chromosome consisting of a single
circular molecule of DNA with associated proteins. - contains genes and noncoding regions called short tandem
repeats (STRs)
DNA and Chromosome
– genetic makeup
Genotype
– manifestation of a genotype
Phenotype
Genetic information is used within a cell to produce the proteins needed for the cell to function.
EXPRESSION
Genetic information can be transferred horizontally between cells of the same generation
RECOMBINATION
Genetic information can be transferred vertically to the next generation of cells
REPLICATION
- one “parental” double-stranded DNA molecule is converted to two identical offspring molecules
DNA Replication
Relaxes supercoiling ahead of the replication fork
DNA Gyrase
Makes covalent bonds to join DNA strands; Okazaki fragments and new segments in excision repair
DNA Ligase
Synthesize DNA; proofread and facilitate repair of DNA
DNA Polymerases
Cut DNA backbone in a strand of DNA; facilitate repair and insertions
Endonucleases
Cut DNA from an exposed and of DNA, facilitate error
Exonucleases
Unwinds double-stranded DNA
Helicase
Adds methyl group to selected bases in newly made DNA
Methylase
Uses visible light energy to separate UV-induced pyrimidine dimers
Photolyase
An RNA polymerase that makes RNA primers from a DNA template
Primase
RNA enzyme that removes introns and splices exons together
Ribozyme
Copies RNA from a DNA template
RNA Polymerase
RNA-protein complex that removes introns and splices exons together
snRNP
Relaxes supercoiling head of the replication fork; separates DNA circles at the end of DNA replication
Topoisomerase or Gyrase
Cuts DNA backbone, leaving single-stranded “sticky ends”
Transposase
Gene Expression: The Central Dogma
DNA -> RNA -> PROTEIN
synthesis of a complementary strand of RNA from a DNA template
Transcription
- protein synthesis
- decoding the “language” of nucleic acids and converting it into the “language” of proteins
Translation
a sequence of three mRNA nucleotides that codes for a particular protein
Codon
code for amino acids
Sense codons
do not code for amino acids
Nonsense codons
the set of rules that determines how a nucleotide sequence is converted into the amino acid sequence of a protein
Genetic code
multiple codons encode for the same amino acid
Degenerate
a single amino acid is indicated for each codon
Unambiguous
reading of the genetic code during translation does not involve overlap of codons
Nonoverlapping
there is no punctuation between codons and reading is continuous until a stop codon
Not punctuated
used by all organisms (w/ some exceptions)
Universal
Amino acid activation -> Chain initiation -> Chain elongation (repeated many times) -> Chain termination
TRANSLATION
Stop Codons
UAA
UAG
UGA
Start Codon
AUG
