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Flashcards in DNA and RNA Deck (53):
1

people involved with semi conservative dna replication

meselson and stahl

2

what is semi conservative dna replication

(copying process of dna) half old dna half new dna for each cell

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cell cycle

g1-s-g2-m

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what is the arrangement of the two polynucleotides in dna

antiparallel

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what is the direction of synthesis

5-3

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what is helicase

unzips helix (unwinds dna) and breaks hydrogen bonds

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DNA polymerase discoverer

kornberg, won nobel prize

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describe dna polymerase

(copies the dna): binds and adds complementary nucleotide & repeats (making the strand on opp side) it follow helicase

9

what are okazaki fragments

a gap on the lagging strand without a phosphodiester bond

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what does ligase do

(seals fragments on the lagging strand) creates phosphodiester bind between okazaki fragments

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what happens in g1

growing and regular functions

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what happens in s of interphase

synthesis, where the replication takes place. 46 to 92 chromosomes

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what happens in g2

growth phase, preparing to divide

14

what are DNA repair proteins

fix mutations in the strand and chops of mutated strand to allow dna polymerase to come and fix it

15

what is apoptosis

"cell suicide" if dna is damaged, will pick up signal and programs cell death

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where does apoptosis take place

mitochondria

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mutation

permanent change that passes repair and apoptosis

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what are most mutations caused by

random copying mistakes

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3 other causes of mutations

radiation, chemicals, infectious agents

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how do cells deal with copying mistakes during replication

dna repair, apoptosis

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benefits of not having a perfect dna replication system

evolution and variety; adaptation

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normal use of apoptosis in the body

shape of organs

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if no apoptosis, example of something that could happen

auto-immune disease, brain growing out of head, tumor

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what organelle does transcription take place in

nucleus

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what does rna polymerase do

copies dna to rna (c-g g-c a-u t-a)

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who was involved with transcription

crick

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difference of dna and rna polymerase

rna polymerase doesnt need helicase, unwinds by itself

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mRNA

(messenger rna) once transcription is complete; carrier of the message to make a protein

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what does rna splicing do

cuts of introns from extrons

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introns

non-coding regions of a gene

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exons

)coding regions of a gene)-code for protein

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codon

mRNA that has been spliced- all exons, no introns

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where do codons go/stay

leaves nucleus, goes to ribosome

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translation

translating the codon into protein

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tRNA/anticodon

carries amino acids to the codon& hydrogen bonds 3 bases

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rRNA

ribosomal rna, made of rna and protein

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large subunit of rRNA

50s, binds amino acids to form a protein

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small subunit of rRNA

30s; coordinates bonding between codon and anticodon

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where does translation take place

ribosome

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what enzyme is involved in transcription

rna polymerase

41

the dna code for an amino acid consists of a sequence of

3 nitrogen bases taken from 4 possible bases

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what makes types of tumors different

the mutations

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benign

not invading or damaging surrounding tissue

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malignant

locally invasive- only invades and damages surrounding tissue

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metastatic

travels to other parts of the body (lymphatic vessel to blood stream)

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oncogenes

normally stimulate growth- needed to grow and live by ALL and they tell cells to divide

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suppressor genes

normally inhibit/stop growth

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repair genes

normally limit mutations, produce proteins that repair DNA

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p53

is a DNA repair protein and is mutated in almost every type of cancer

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p53 mechanism of action

binds to specific section of introns, grabs RNA polymerase

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p53 genes it affects

controls the expression of 2- cant stop a cell from dividing or cant go into apoptosis

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WAF

cellular break

53

PUMA

apoptosis gene