Unit 1 : DNA Flashcards

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1
Q

4 stages of hypothesis for the formation of the 1st cell

A
  1. abiotic (non living) synthesis of small organic molecules
  2. small molecules into macromolecules
  3. packaging of molecules into protocells (prokaryotic cells)
  4. origin of self replicating molecules
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2
Q

Describe the Miller - Urey Experiment

A

they created an experiment to see if water vapor cooled our oceans and wanted to see what was in it and to see if it was possible that macromolecules could be formed

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3
Q

What is a protocell?

(lipids and other molecules?)

A

May have been fluid filled vesicle
- they lipids and other molecules can form vesicles formation

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4
Q

What can increase the rate of vesicle formation? What substrate?

A

adding clay can increase the rate of vesicle

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5
Q

What properties of life vesicles can exhibit?

A
  • simple growth
  • reproduction
  • metabolism
  • maintenance of internal environment
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6
Q

Why is RNA the 1st genetic material and not DNA?

A

Due to hypothesis protocells were able to form on earth and they grew and split and passed RNA to their “daughters” and RNA can replicate itself and not DNA

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7
Q

What catalyzes different reaction?

A

ribozymes

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8
Q

Why is it important that earth has a reducing atmosphere?

A

due to the lack of oxygen and other gases and vapors, which prevents oxidation,

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9
Q

What did morgans group showed ?

A

showed genes are located on chromosomes and made of DNA and held together by proteins.

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10
Q

How was the role of DNA 1st discovered?

A

discovered by studying bacteria and viruses that can infect them.

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11
Q

Griffith Experiment

A
  • worked with two strains of bacteria (pathogenic, harmless)
  • transformation: the strains could change it self
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12
Q

What did Avery, Mccarty, and MacLeod established?

A

20 years later they affirmed griffith experiment
- you can transform cells with just DNA and change behavior

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13
Q

Pathogenic vs. Harmless strains of bacteria

(Griffith Experiment)

A

(S strain) Pathogenic: smooth - body doesn’t recognize it (deadly) pneumonia
(R starin) Harmless: rough - body attacks it (not deadly)

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14
Q

Hershey - Chase

A
  • they used viruses to see if it was protein or DNA, which has sulfur
  • showed that DNA is the genetic material of the T2 phage (virus)
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15
Q

Double Helix

A
  • franklin and wilkins discovered that DNA was a double helix
  • franklin concluded that 2 sugar phosphate backbones with nitrogenous bases
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16
Q

Franklin, Watson, Cricket,

A
  • franklin discovered double helix in DNA
  • watson and cricket formed a model of double helix (leaked info from franklin)
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17
Q

Translation

mRNA

in cytoplasm

A

process in which the information encoded in a strand of mRNA is used to construct a protein
- where tRNA & mRNA work together to make polypeptide
happens in the cytoplasm and ribosomes are involved (eukaryotic cells)

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18
Q

Transcription

tRNA

in nucleous

A

making mRNA using info in DNA
- (DNA directed synthesis of RNA)
- strand of DNA is used as a template for the manufacture of a strand of pre-mRNA

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19
Q

Polypeptide

A

1 small bead from translation = 1 amino acids

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20
Q

tRNA vs mRNA

definition

A

tRNA - transfer (role in protein synthesis, translation)
mRNA - messenger

21
Q

Primary transpict

A

initial RNA transcript from any gene prior to processing (pre mRNA)

22
Q

Promoter, TATA Box

A

TATA box - a lot of thymine & adenine
- tata box must bind to DNA before RNA polymerase can bind in the right position
Promoter - DNA of a gene that binds to RNA polymerase

23
Q

RNA polymerase

A

breaks DNA strands apart and join together the RNA nucleotides
- the promoter starts transcribing a gene for RNA polymerase

24
Q

DNA template strand

A

read it from 3 prime to 5 prime
- nucleotides in RNA sequence

25
Q

Codon Strand

mRNA

A

read it from 5 prime to 3 prime
- same sequence as mRNA but T instead of U
- codon

26
Q

RNA processing

definition

A

pre mRNA to mRNA
- enzymes modify pre mRNA before its sent off to cytoplasm
- slicing
- happening in nucleus

27
Q

5’ cap

A

sequence of nucleotides that are going to get added to the 5 prime end of mRNA
- where ribosome is going to attach

28
Q

poly-A-tail

A
  • added on 3 prime end (adenine)
  • poly-A-tail protects mRNA
29
Q

modifications for 5’ cap & poly-A-tail

A

export of mRNA to cytoplasm
- enzymes can break the bond between nucleotides
- helps ribosomes attach to the 5’ end.
- we need mRNA out
- protect RNA
- ribosome to bind to RNA to start translation

30
Q

Exons & Intron

A

exons - exit the nucleus
intron - stay in nucleus will not be apart of the final translation process

31
Q

Spliceosome

A
  • proteins make spliceosomes
  • cut out introns
32
Q

Ribozymes

A

RNA molecules that function as enzymes and can splice RNA

33
Q

alternative RNA splicing

A

some genes can encode more than one kind of polypeptide

34
Q

Transfer RNA

(tRNA)

A

translating mRNA into protein
- tRNAS transfer amino acids to polypeptides in a ribosomes

35
Q

Anticodons

tRNA

A

base-pairs with codon on mRNA

36
Q

A site / P site / E site

A

A site - holds tRNA that carries to the next animo acid (do i fit in with the codons)
P site - tRNA carries the polypeptide chain
E site - exit site tRNAs leave the ribosomes

37
Q

operon model

A
  • bacteria
    type of regulation of groups of genes
38
Q

operator

A

switch is a segment of DNA

39
Q

operon

bacteria

A

includes operator, promoter, and genes they control
- it can be switched off by a protein called repressor

40
Q

repressor

A

bound to tryptophan, then binds to dna to turn off and blocks RNA polymerase transcription

if repressor is binded RNA polymerase cant transcript

41
Q

regulatory gene

A

located some distance from the operan

42
Q

tryptophan

(trp)

A

is an amino acids, operon is on
- trp is turned off by REPRESSOR if tryptophan is making too much

43
Q

lac

A

bacteria breaks down lactose because bacteria likes glucose (sugar)
- catabolic
- wont turn on unless lactose is around

breaks things down

44
Q

cyclic AMP

(cAMP)

A

cAMP activates protein CRP
- CRP binds to promoter of lac operon which increases RNA polymerase accelerating transcription
- when glucose starts to leave cAMP and CRP increases the rate of trancription and translation to make more enzyme and break down lactose at a faster rate

positive gene regulation turning up the volume

45
Q

Chromatic modification

1st step in gene expression in eukaryotic cells

histone acetylation, DNA methylation

A

histone acetylation - loosens chromatin structure promoting the start of transcription
DNA methylation - with reduced transcription, causes long term inactivation of genes in cellular differiation

nucleosomes

46
Q

Transcription Regulation

2nd step in gene expression in eukaryotic cells

A

transcription factors - needs help from RNA polymerase to start transcription
some bind to tata box (promoter region)
- when the start is complete RNA polymerase can begin to move along the templagte strand
- activators (protein) bind to enhancers (DNA)

47
Q

RNA proccesing

3rd step in gene expression in eukaryotic cells

A
  • alternative RNA splicing (introns)
  • RNA segmants treated as exons
48
Q

Protein degration (protesomes)

4th step in gene expression in eukaryotic cells

A
  • once protein made in cytoplasm gets tagged by ubiqutin
  • protein enters proteosomes
  • when non more needed ubiqutin gets recycled