Chapter7 Flashcards
A) What is a genome?
complete set of genetic info
B) What is a gene and what does it do?
functional unit of a genome. it encodes protiens
C) What is the study of nucleotide sequences called?
gemnomics
D) What two tasks must all cells accomplish to multiply? [Figure 7.1]
Double stranded dna must be repicated
info must be decoded so cell can synthesize protiens
1) What happens during transcription and translation?
Translation:interperets the info to synthesize encoded protien
Transcription:Copies info using rna
1) Why are the ends of DNA referred to as 5’ end and 3’ end?
number assigned due to number of carbons in the structures.
5 and 3 are where nucleotides bind together
2) Why are the DNA strands antiparallel?
oriented in diff directions because one goes 3-5 the other 5-3 ends
F) What are the main differences between DNA and RNA?
rna made of ribonucleotides. has uracil instead of thyamine, usually single stranded
G) What are the three functional types of RNA and what do they do? [Figure 7.3]
mrna: holds info and corrilates the nucleotides to a aa to make protiens
trna
rrna when rna is the end product.
H) How is gene expression controlled? [Figure 7.4]
turn off transcript and reduce the number of transcripts decline
A) How are bacterial chromosomes replicated? [Figure 7.5 and Table 7.1]
through bionary fission.
1) What is the replication fork?
where dna synthesis occurs in between the 2 bacteria on both ends
2) Why is the replication said to be semiconservative?
because each cell has .5 of the original dna and the other half is synthesised
3) What is the origin of replication?
to initiate replication protiens must bind to distinct dna sequences
4) What is the role of primers?
recorded segments of rna from dna
5) What is the role of DNA polymerase? [Figure 7.6]
synthesize dna in 5-3 direction. They add nucleotides on end of 3 to start reaction which provides e
6) What are the differences between synthesizing the leading and lagging strand? [Figure 7.7]
leading is on 3 side which is composed of nucloetides.
The 5 is more complicated and requires that rna primer is used.
A) What is transcription and how is it done? [Table 7.2}
When rna makes a copy of dna
1) What is the role of RNA polymerase? [Figure 7.8]
synthesizes single stranded rna from dna
2) What is the promoter and terminator?
promoter: on the dna which tells where rna sould start copying and terminator is what tells it where to stop.
3) How does RNA made during transcription compare to the DNA template? [Figure 7.9]
It is opposite/ the pair of the minus strand of dna, but with uracil instead of thyamine
4) What are the plus and minus strands?
minus is the strand used as teh template. Plus is the opposite side.
5) What is the difference between monocistronic and polycistronic mRNA molecules?
transcript that covers 1 gene
one that carries multiple genes
B) How is RNA synthesized? [Figure 7.10]
process initiated when rna polymerase binds to the promoter causing it to unzip.
then sigma factors leave rna to complete transcription.
1) What is the sigma factor?
part of the polymerase that recognizes the promotor
2) What is the role of the promoter? [Figure 7.11]
help rna know where a new sequence begins
3) What happens during the elongation phase?
sigma facotr dissociates from rna, leavinf it to complete transcription.
D) What is translation and what happens during this process? [Table 7.3]
process of decodign infor carried on mrna to synthesize a specific protien
1) What is mRNA’s job? [Figure 7.12]
act as temporary copy of dna
-What is a codon? [Table 7.4]
series of 3 nucleotides
-What are reading frames? [Figure 7.13]
how triplets( 3nucleotides) are grouped
2) What is the role of ribosomes?
strings amino acids together
3) What does tRNA do? What type of structure does it have? [Figure 7.14]
trna recognizes different and base pairs codons and then delivers proper aa to that area.
has anticodon.
-What are anticodons?
has complimentary nucleotides to codon of mrna
4) How is translation initiated? [Figure 7.15]
by ribosome binding to mrna
-Why is AUG important?
usually the “start” codon
5) How is the polypeptide chain elongated? [Figure 7.16]
????2 rna’s bind to a nd p sites on ribosome. this matches up the aa’s and allows them to bind to eachother
-How is the elongation terminated?
when ribosome reaches the stop codon. free poly peptide by brekinf covalent bond holding ti to trna
6) What do chaperones do to some polypeptides?
chaperones help fold poly peptides
A) How do eukaryotes differ from prokaryotes in transcription and translation? [Table 7.5]
prokaryotes: mrna is not processed, mrna doesnt contain introns, translation of rrna begins as it is being translated, mena is often polyinstronic.
1) What is splicing? [Figure 7.17]
taking a segment of hte transcript out
2) What are introns and exons?
interveining sequences
expressed region
A) What is signal transduction?
takes signal from out of cell and brings it in.
B) What is quorum sensing, how is it done, and why is it useful? [Figure 7.18]
sense density of cells in their own poplulation. this helps them to know if there is enough of them to make it worth it to activate certain genes
C) What is the two-component regulatory system, how is it done, and why is it useful? [Figure 7.19]
way cells detect changes in environment. know for switching to alternate metabolism. A sensor detects variation and in response phosphorylates a aa. the phosphate is then transfered ro regulator which can turn on or off a cell.
D) What is antigenic variation and how does demonstrate the role of natural selection?
alteration in characteristics of surface protiens. This can help them stay a step ahead of bodies defenses so they can stay alive.
E) What is phase variation? Give an example.
7.6 Bacterial Gene Regulation [pg. 179]
routine of switching on and off genes. ecoli and pilli alowing them to attatch and detatch
A) What is an operon? What are regulons?
regulated genes transcribed by one polyintrisic messade,
regulond: seperate operons that are controlled by a singular regulatory mechanism
B) What are the three enzyme groups and what are their characteristics? [Figure 7.20]
constitutive:enzymes that are synthesized constantly( always active)
Inducible: are not routinely working( can be turned on when needed)
Repressible: produced routinely, but synthesis cna be turned off when not needed.
C) What are the alternative sigma factors and what do they do?
recognize different promotors
D) What is a repressor and how does it work? [Figure 7.21]
regulatory protien that blocks transcription
What are the two function by which repressors function?
- induction- repressor is synthesized and binds to the operator.
- repression-doesn’t bind to the operator
E) What is an activator and how does it work? [Figure 7.22]
facilitates transcription.
Bbinds to site and enhances ability of rna to to initiate transcription.
F) What is the lac operon and why is it important? [Figure 7.23]
operon that encodes proteins to degrade lactose. So that way if source of glucose is gone it can switch to lactose
1) What happens when lactose or glucose is in the cell? [Figure 7.25]
gluclose there is a repressor that prevents transcription when lactose is not available
) What is CCR?
3) What is diauxic growth? [Figure 7.24]
ccr- carbon catabolite repressor which represses the lac when a better source of carbon( gluclose is present)
diauxic growth: when growth is on 2 different nutrients
4) What is inducted exclusion?
when the gluclose transporter component binds to lac preventing it from activating
A) What is RNA interference? [Figure 7.26]
uses rna to locate other rna to destory them.
A) What is the field of bioinformatics?
computer tech used to retrieve and annalyze nucleotide sequences
B) What are ORF and how can they be used?
Open reading frames: help find the start and end sequences and helps us know codes for protiens
C) What is Metagenomics?
annaysis of total microbial genomes in an environment
