chapter 10 continued- gene expression Flashcards
-proteins are the links between genotype and phenotype
-a gene sends instructions in the form of mRNA which programs protein synthesis through transcription and translation
- dna in nucleus to rna to protein synthesis in the cytoplasm
central dogma of biology
provides template for protein synthesis during translation
carrie’s transcript of dna
mrna
brings amino acids and reads genetic code during translation
trna
makes up ribosomes with other ribosomes
rrna
how does dna control cell activity?
dna is used as a template to make rna (transcription) and rna is used as a template to make protein (translation)
3 nucleotide bases of mrna that codes for an amino acid
codon
complimentary bases of codon located on trna
anticodon
where does transcription occur and what is it
occurs in nucleus
converts dna to mrna
first step of transcription
rna polymerase unwinds dna
step 2 of transcription
rna polyermase adds rna nucleotides
processing steps of transcription
add cap and tail and remove introns (non coding)
where does translation occur
cytoplasm
first step of translation
players arrive and ribosomes attach to to mrna at start codon and trna brings first amino acid
second step in translation
next trna brings next amino acid to ribosomes to make a polypeptide. trna brings anti codon to codon from mrna
last step in translation
ribosome reaches stop codon
change in dna nucleotide sequence
mutation
_______ substitutions is a point mutation where…
exchange one nucleotide with a mother
base substitution changes codon and results in different amino acid
missense mutation
base substitution changes codon but same amino acid
silent mutation
base substitution stop codon results in a incomplete, ________________ protein
nonsense substitution
insertions and deletions
add or remove one or more dna nucleotides
framwshift mutation results in
different amino acid sequence
what is the source of mutation
mutagenesis
mistakes made during dna replication that are not corrected are _________ mutations
spontaneous
agents that cause mutations are called
mutagens (x-rays, uv rays, chemicals)
what is a virus
infectious particle
what do viruses need to reproduce
a host cell
virus that attacks prokaryotic cells
phage
phages are made of
nucleic acid (dna or rna)
outer protein coat (capsule)
host cell explodes (lyses) releasing new viruses (what type of reproductive cycle is this?)
lytic
viral dna combines with host cell dna and lies dormant unless an environmental trigger sets it off (what reproductive cycle is this?)
lysogenic
type of virus that is new, and emerges from one specific location and spreads rapidly
emerging virus
