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Biochem > Biochem Exam 2 - Quan > Flashcards

Biochem Exam 2 - Quan Flashcards

1
Q

What is genetics?

A

It is the study of heredity, it involves the study of cells, individuals, their offspring, and populations within which organism lives.

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2
Q

What is a monohybrid cross?

A

It is made by mating individuals from 2 parents stains each which exhibit 1 of the 2 contrasting forms of the character under study. They have different alleles for one genetic characteristic. Like mating a yellow pea pod with a green pea pod. (original parents = P1, their offspring = F1)

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3
Q

What is phenotype?

A

The observable properties of an organism that are genetically controlled.

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4
Q

What is genotype?

A

The specific allelic or genetic constitution of an organism.

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5
Q

What is an F1 cross?

A

this results in F2 generation.

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6
Q

What are Mendel’s first 3 postulates?

A

1) Unit factor 2) dominance/recessiveness 3) segregation

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7
Q

What is unit factor?

A

genetics factors are controlled by unit factors that exist in pairs in individual organism.

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8
Q

What is Dominance/recessiveness?

A

when 2 unlike unit factors for a single factor are present in a single individual, one unit factor is dominant to the other which is said to be recessive.

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9
Q

What is segregation?

A

During formation of gametes the paired unit factors separate or segregate randomly so that each gamete receives one or the other with equal likelihood.

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10
Q

What is punnett squares?

A

a diagram that is used to predict an outcome of a particular cross or breeding experiment.

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11
Q

What is dihybrid cross?

A

constructed by mating individuals from 2 parent strains when genes under study are on different chromosomes. These are 2 pairs of contrasting forms of character under study, individuals resulting from self-fertilization of the F1 generation are called F2. 9:3:3:1

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12
Q

What is a gene?

A

a sequence of DNA bases containing biologically useful information (unit factor)

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13
Q

What is a genetic locus?

A

specific position or location of a gene on a chromosome.

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14
Q

What is an allele?

A

alternative form of a gene (unlike a unit factor)

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15
Q

What is a homologue?

A

the first division in meiosis separates homologous chromosomes, which aren’t identical.

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16
Q

What are the divisions in meiosis?

A

the first division in meiosis separates homologous chromosomes. The second division in meiosis separates sister chromatids.

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17
Q

What is diploid?

A

cells contain two sets of chromosomes

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18
Q

What is a haploid?

A

condition in which cells contain one set of chromosomes (eggs and sperms are also called gametes).

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19
Q

What is independent assortment (4th postulate)?

A

during gamete formation, segregating pairs of unit factors assort independently of each other.

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20
Q

What is incomplete and partial dominance?

A

combining gene products from two alternative alleles produces an intermediate phenotype, one factor doesn’t dominate the other. Ex) Rr x Rr = RR, 2Rr, rr, R=red, r = white. Rr = pink

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21
Q

What is co-dominance?

A

if 2 alleles are responsible for the production of two distant and detectable products; the distinct genetic expression of both alleles in a heterozygote is called co-dominance. ex): A, B, AB blood types

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22
Q

What is polymorphism?

A

the existence of 2 or more discontinuous, segregating phenotypes in a population (blood types). At that genetic level for blood it is polymorphic we have different genotype BUT it is normal.

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23
Q

What is epistasis?

A

the phenomenon of masking/modifying the effects of one gene pair by the expression of another. (ex: Bombay phenotype).

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24
Q

What is Bombay phenotype?

A

a rare genetic trait where there is no expression of the A, B or H antigens on rbc. Bombay phenotypes (hh) lack the H gene which produces the H antigen, a precursor for A and B antigens. Since H isn’t expressed, A or B can’t be expressed.

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25
Q

What is lethal allele?

A

expression or lack of expression of certain genes can affect the survival of an organism. (ex: agouti and yellow mice, pure yellow genotype will kill the mouse).

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26
Q

What is sex linkage?

A

the gene that determines a specific character is location on a sex chromosome. Not going to distribute evenly in both sexes since one is XX and one is XY.

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27
Q

What is crossover?

A

during meiosis a limited number of crossover events occur randomly between homologous chromosomes, the closer the two loci reside on the axis of the chromosomes the less likely it is that any crossover event will occur between them. The further the genetic distance the HIGHER the chance of crossing over.

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28
Q

What is penetrance?

A

a genetic disorder is the proportion of individuals with the at-risk genotype who actually express the trait, complete penetrance means the trait is expressed in 100% of persons with that genotype (ex: Huntington’s disease)

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29
Q

What are restriction enzymes?

A

enzymes that cut the DNA sequence in specific locations.

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30
Q

What are blunt ends?

A

can allow joining of different DNA, blunt ends cut. The end of a DNA fragment resulting from the breaking of DNA molecule in which there are no unpaired bases, so both strands are of the same length.

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31
Q

What are adhesive ends?

A

jagged ends left after restriction enzymes cut them. Has has protruding single-stranded strands with unpaired nucleotides called overhangs, each overhang can anneal with another complementary one to form base pairs.

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32
Q

What are end-labeling?

A

labels the 5 prime end with phosphate. useful for visualizing DNA

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33
Q

What is in situ hybridization?

A

uses labeled complementary DNA or RNA probe to localize a specific DNA or RNA sequence in a portion of.a tissue and also locates specific genes on the chromosomes.

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34
Q

What is insertion of DNA into a bacterial plasmid?

A

A circular double stranded plasmid DNA (cloning vector) undergoes cleavage with a restriction nuclease, addition of the DNA fragment to be cloned which undergoes covalent linkage by DNA ligase resulting in recombinant DNA.

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35
Q

What is plasmid?

A

a virus that can live in bacteria

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36
Q

What is ligase?

A

an enzyme that can catalyze the joining of two large molecules by forming a new chemical bond, usually with accompanying hydrolysis.

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37
Q

What is the genomic DNA library?

A

Is is collection of the total genomic DNA from a single organism. It is a human double stranded DNA and to do this the DNA is cleaved with restriction nuclease, now has millions of genomic DNA fragments, those DNA fragments are inserted into plasmids, and now you have recombinant DNA molecules.

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38
Q

What is cDNA?

A

cDNA refers to complementary DNA. It is known to be synthesized from mRNA (messenger RNA - a large family of RNA molecules that deliver genetic information to ribosome from DNA to make the amino acid sequence for protein synthesis during translation). cDNA is made in a run that is catalyzed by the reverse transcriptase and DNA polymerase enzymes. cDNA is used to clone eukaryotic genes in prokaryotes. Scientists use it when they want to express a protein in a cell that doesn’t normally express that protein.

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39
Q

What are the step for synthesis of cDNA?

A

1) lyse (disintegration) cells and purify mRNA
2) hybridize (crossbreed or mix) with poly T primer ( a single sequenced primer used for priming reaction catalyzed by reverse transcriptase).
3) make DNA copy with reverse transcriptase
4) degrade RNA with RNase
5) synthesize a complementary DNA strand using DNA polymerase (makes DNA from nucleotides)
6) RNA fragments act as a primer
7) double stranded cDNA copy of original mRNA

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40
Q

What’s the difference between cDNA and genomic DNA?

A

Genomic DNA has introns (introns are non-coding regions or “junk” DNA because they give you no information about protein coding so during RNA splicing, introns are removed and exons are joined together to form a contiguous coding sequence) whereas the mRNA that made the cDNA didn’t have any (probably because the introns were spliced before cDNA was made).

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41
Q

What s DNA foot printing?

A

It’s a method used to determine the exact DNA sequence to which a particular DNA-binding protein binds.

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42
Q

What are the steps of DNA foot printing?

A

1) region of DNA protected by DNA binding protein
2) random cleavage by nuclease or chemical followed by removal of the protein and separation of the DNA strands.
3) family of single-stranded DNA molecules labeled at the 5’ end
4) separation by gel electrophoresis
5) foot print is where no cleavage is observed.

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43
Q

What is site-directed mutagenesis?

A

it is an in vitro method used to make specific and intentional changes to the DNA sequence of a gene or any gene products. It’s a great way to create a specific mutation/introduce a mutation into the DNA sequence to see what happens.

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44
Q

What are the steps of site-directed mutagenesis?

A

1) plasmid cloning vector and inserted gene
2) strand separation
3) synthetic oligonucleotide primer containing desired mutated sequence
4) strand completion by DNA polymerase and DNA ligase
5) introduction into cells followed by replication and segregation into daughter cells.

45
Q

What is gene targeting?

A

Gene targeting is a genetic technique that uses homologous recombination to change an endogenous gene (gene that originated from within an organism, tissue, or cell). The method can be used to delete a gene, remove exons, add a gene, and introduce point mutations. Gene targeting can be permanent or conditional (it can be controlled).

46
Q

What are the step of gene targeting?

A

1) embryonic stem cells growing in tissue culture
2) introduce a DNA fragment containing altered gene into many cells
3) let each cell grow to form a colony
4) test for rare colony in which the DNA fragments has replaced one copy of the normal gene.
5) inject ES cells into early embryo

47
Q

What is DNA transcription?

A

Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA (especially mRNA) by the enzyme RNA polymerase.

48
Q

What is the first step of transcription?

A

Initiation (start): RNA polymerase binds to DNA at a specific sequence of nucleotides called the promoter.
The promoter contains an initiation site where transcription of the gene begins.
RNA polymerase than unwinds DNA at the beginning of the gene.

49
Q

What is the second step of transcription?

A

Elongation (make): Only one of the DNA strands acts as a template for the RNA synthesis.
RNA polymerase can only add nucleotids to the 3’ end of the strand so like DNA, RNA must be synthesized in the 5’ to 3’ direction.
Free ribonucleotides triphosphates from the cytoplasm are paired up with their commplementary base on the exposed DNA template.
RNA polymerase joins the ribonucleoside triphosphates to form an mRNA strand.
As RNA polymerase advances, the process continues.
The DNA that has been transcribed, re-winds to form a double helix.

50
Q

What is the third step of termination?

A

Elongation (stop): RNA polymerase continues to elongate until it reaches the terminator, a specific sequence of nucleotides that signals the end of transcription.
Transcription stops and mRNA polymerase and the new mRNA transcript are released from DNA.
The DNA double helix reforms.
The termination sequence usually consists of a series of adjancent adenines preceded by a nucleotide palindrome.
This gives an RNA molecule that assumes a stem-and loop configuration.
This configuration stops RNA polymerase from transcribing any further.

51
Q

What’s a promoter?

A

A DNA sequence that determines the site of transcription initiation for an RNA polymerase: it is noncoding, asymmetric so therefore polymerase will always bind in the proper orientation and can only synthesis 5’ -> 3’ direction.

52
Q

What is the difference between template and coding strand of DNA?

A

The RNA sequence is complementary to the template strand, and identical to the coding strand. Either DNA strand may serve as the template. DNA is listed as coding strand in a genome with introns.

53
Q

What is the function of a sigma factor?

A

This is important for the initiation phase. Different Sigmar factors recognize and bind to different consensus promoter specific sequences near the 10 to -35 positions of the promoter. They basically direct transcription initiation in the right direction and is something that enables specific binding of RNA polymerase to gene promoters.

54
Q

What are consensus regions in a promoter?

A

It is when different sigma factors recognize different consensus promoter sequences.

55
Q

What is the structure of transcription termination in prokaryotes?

A

The stem loop formation terminates transcription. Another term is the hair-pin loop so basically the RNA polymerase just comes off of the sequence so it can’t transcribe anymore.

56
Q

What is polycistronic transcription?

A

is a an operon composed of genes that are transcribed as single mRNA, all 5 genes code for enzymes necessary for tryptophan synthesis.
DNA has one promoter and 5 genes. RNA transcribes one RNA. The protein translates 5 proteins.

57
Q

What is monocistronic transcription?

A

This occurs in eukaryotes. 1 gene controls the production of one protein and the control regions are a lot longer.

58
Q

What is an operon?

A

adjacent genes transcribed as a single mRNA.

59
Q

What’s a repressor?

A

They bind to DNA sequences called operators, which overlaps the promoter region. A bound repressor interferes with binding of RNA polymerase and transcription initiation.

60
Q

What is an operator?

A

a segment of DNA to which a transcription factor (activator or repressor) binds to regulate gene expression.

61
Q

What is the regulation of lac operon?

A

this is under both negative (repressor) and positive (by CAP protein - activates transcription of lac operon by RNA polymerase) transitional controls.

  • when you have + glucose and + lactose = operon is turned off because CAP is not bound to the promoter.
  • +glucose, -lactose = operon off b/c lac repressor is bound and CAP is not bound
    • glucose, -lactose = operator off b/c lac repressor is bound
    • glucose, + lactose = operon on

TRY TO KNOW MORE ABOUT THIS ON YOUR OWN

62
Q

What are the components of chromatin?

A

DNA is wrapped around protein, DNA, exons, introns, regulatory sequences, junk, and proteins (histone).

63
Q

What is a heterochromatin?

A

densely packed, cluster near the nucleolus and nuclear member; transcriptionally silent - doesn’t undergo transcription because it’s so tightly packed.

64
Q

What is euchromatin?

A

loosely packed - transcriptionally active - so undergoes transcription because it’s “open”

65
Q

What are transcriptional regulation by chromatin modifications?

A

modifications of histone tails can tight or loosen the nucleosome.

66
Q

What is acetylation in transcription regulation?

A

this is when lysine residues in N -terminals sticking out of histones of the nucleosome are acetylated (an acetyl group is attached to the histone tails of nucleosomes). This affects gene expression because this loosens up nucleosome so the DNA in there is readily available for to be transcribed. It basically unwinds/activates the chromatin from a tight ball so it can be transcribed.

67
Q

What is methylation in transcription regulation?

A

Methyl groups are transferred to the chromatin to actually have the DNA wound back up - so it tightens/deactivated the chromatin so the DNA inside of it won’t be transcribed. Methyl groups are kind of big so think that if something big is there, then it’s going to be hard for the DNA to be transcribed because the methyl group is in the way.

68
Q

Which polymerase transcribes mRNA?

A

polymerase II

69
Q

What are general transcription factors?

A

factors that bind to all genes, there are needed to bind Polymerase II to the promoter. Once the TATA-binding protein (TBP), a general transcription factor, binds to a DNA sequence called the TATA box, than a bunch of other transcription factors start attacking which initiated transcription.

70
Q

What are the location of enhancers?

A

DNA sequences outside that are in front or behind the gene, can work upstream, downstream, or in reverse orientation.

71
Q

What is an enhancer?

A

an enhancer is a short region of DNA that can be bound by proteins (activators) to increase the likelihood that transcription of a particular gene will occur. These proteins are usually referred to as transcription factors

72
Q

What is phosphorylation in transcriptional regulation?

A

It activates/looses chromatin - I think

73
Q

What is the function of an insulator?

A

it limits the distance that enhancers operate. There are DNA sequences that bind specialized proteins. These proteins buffer the gene from outside effects, prevent the control region from acting outside the domain, prevent the spread of heterochromatin.

74
Q

What is a DNA binding domain?

A

This can be classified into numerous structural types including zinc finger proteins (Zinc finger proteins are among the most abundant proteins in eukaryotic genomes. Their functions are extraordinarily diverse and include DNA recognition, RNA packaging, transcriptional activation, regulation of apoptosis, protein folding and assembly, and lipid binding.) and leucine zipper proteins (The leucine zipper is a common three-dimensional structural motif in proteins and it has that name because leucines occur every seven amino acids in the dimerization domain. The localization of the leucines are critical for the DNA binding to the proteins.). DNA-binding proteins include transcription factors which modulate the process of transcription, various polymerases, nucleases which cleave DNA molecules, and histones which are involved in chromosome packaging and transcription in the cell nucleus.

75
Q

What are the steps of RNA processing (like after transcription)?

A

1) 5-cap prevents the degradation of the sequence
2) poly A tail enzyme adds the tail, no A’s in DNA they are on the RNA
3) splicing cuts out introns to give mRNA, there is a specific sequence at the end of the intron that allows the spliceosome to recognize that area to cut it.

76
Q

What is alternative splicing?

A

cutting a single gene to two so it can code for more than one protein. Must be able to be divided by 3.

77
Q

What is poly A?

A

Poly A’s are not in DNA, the multiple A’s in RNa are not copied from DNA, these come and attach onto the RNA at a later time. The poly A site is a specific sequence that an enzyme can recognize and add a bunch of A’s on the RNA.

78
Q

What is intercellular signaling?

A

how cells communicate with each other

79
Q

What is intracellular signaling?

A

signaling occurring inside the cell

80
Q

What are the functions of intercellular signaling?

A

1) extracellular signal binds to receptor protein
2) the receptor gives off three signaling proteins
3) each signal proteins reach their target protein by appropriate protein (metabolic enzyme, gene regulatory protein and cytoskeletal protein)
- all of these will alter the metabolism, gene expression and cell shape/movement.

81
Q

Where are the location of receptors?

A

cell surface receptors (which are large hydrophilic molecules that bind to the receptor) and intracellular receptors (small hydrophobic molecules that go into the cell)

82
Q

What are the different forms of intercellular signaling?

A

1) contact-dependent (when cells touch)
2) paracrine (cell sends signals to neighboring cells)
3) synaptic (neurotransmitter from an axon to a cell - very precise)
4) endocrine: hormones into the blood and target cells (generalized signal)
5) Autocrine: (one cell is signaling itself, it’s week but multiple autocrine signaling is strong)
6) gap signaling: (cardiac cells so everything contracts together - everything is being signaled at the same time so the heart can contract)

83
Q

Can one signaling molecule perform multiple functions?

A

YASSSSS. Acetylcholine in the muscle causes the muscle to contract, whereas in the cardiac muscles it causes it to relax and decreases HR and in the salivary glands it helps you secrete saliva.

84
Q

How can signaling occur through cascade of intermediate signaling complexes?

A

1) receptor protein - receives chemical signals from outside of the cell
2) scaffold protein (can have preassembled scaffold: relay proteins already attached to scaffold protein, you can also have assembling as activation occurs) - either hold protein kinases in a latent state close to their activating cell-surface receptors, or facilitate flow of activation from one kinase to the next kinase in a signaling cascade.
3) relay protein: pass the message to the next signaling component in the chain without otherwise participating.
4 ) adaptor protein: link the components of signaling pathways by acting as accessories to the chief proteins in a signal transduction pathway.
5) bifurcation protein: spread the signal from one signaling pathway to others.
6) amplifier protein: are usually either enzymes or ion channels. Amplifiers increase the received signal by producing large amounts of small intracellular second messengers or by activating large numbers of downstream intracellular signaling proteins.
7) small intracellular mediator (aka second messengers): they pass the signal on by binding to and altering the behavior of selected signaling proteins or target proteins.
8) integrator protein: integrate signals from two or more signaling pathways and relay the signal onward along a single pathway.
9) anchoring protein: provide a molecular framework that orients these enzymes towards selected substrates.
10) messenger proteins: carry the signal from one part of the cell to another. For example, messengers often carry signals from the cytosol to the nucleus.
11) target protein: control the action and the kinetic behavior of drugs within the organism

85
Q

What are the types of ligand that interact with intracellular receptors?

A

steroid hormones (estrogen, progesterone, testosterone, aldosterone, glucocorticoids, DHEA) hydrophobic can penetrate the membrane easily. DNA bind domain, ligand binding domain and transcription-activation domain and an inhibitory protein. When the hormone comes in it binds to an intracellular receptor and activates transcription.

86
Q

What are inotropic receptors?

A

extracellular, these are receptors that can serve as an ion channels. Ex) nicotinic AChR: binding of the receptor allows the opening of the channel.

87
Q

What are metabotropic receptors?

A

are indirectly linked with ion channels on the plasma membrane of the cell through signal transduction mechanisms, often G proteins. also called G-protein linked receptors. Ex) muscarine acetylcholine receptor

88
Q

What are the steps of receptor inactivation?

A

1) receptor sequestration: taking a receptor off the extracellular surface and bring it in so it can no longer function
2) receptor down regulation: a receptors gets eaten up by a lysosome
3) receptor inactivation: receptor remains on the extracellular surface and just gets deactivation.
4) product can also go back and inactivate a receptor.

89
Q

What are G-protein coupled receptors?

A

1) alpha S - stimulate adenylate cyclase (an enzyme with key regulatory roles in essentially all cells)
2) alpha I - inhibit adenylate cyclase
3) alpha Q - activation Phospholipase C (PLC - a class of membrane-associated enzymes that cleave phospholipids just before the phosphate group) – PLC connects to IP3 (is a secondary messenger molecule used in signal transduction and lipid signaling in biological cells.) pathway.

90
Q

What is the dissociation of G-protein subunits?

A

The g-protein will dissociate when it is activated. It dissociates into beta and alpha subunits. The alpha subunit has a GDP attached to it so once it is activated, it gets phosphorylated to GTP.

91
Q

What are the steps of cyclic AMP (cAMP) cascade?

A

1) beta receptors gets activated by NE
2) this activates a G protein
3) the G protein activates adenylate cyclase
4) adenylate cyclase then converts ATP to cAMP (second messenger)
5) cAMP then activates PKA (is a family of enzymes whose activity is dependent on cellular levels of cyclic AMP)

92
Q

What does PKA do in cAMP cascade?

A

adds a kinase to a molecule to activate it. protein phosphatase 1 strips the phosphate off the molecule and then inactivates it (not always the case)
-PKA dissociates the regulatory element when activated by cAMP.

93
Q

Where do IP3 and DAG (is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages.) come from?

A

1) AcH activates the beta receptor
2) which activates a Gq protein
3) the Gq protein activates PLC which cuts a lipid molecule into a IP and DAG (second messengers)
4) IP then binds to another receptor that opens an intracellular calcium channel on the ER, increasing intracellular calcium
5) calcium then bind to open up a coloring channel. Sodium follows the chloride and so does water.

94
Q

What are enzyme-linked receptors?

A

tyrosine kinase receptors, no G proteins involved. These are involved in growth factors.
1) the ligand connects bringing two tyrosine kinase domains together that then auto-phosphorylate each other (dimerization).

95
Q

What is Das?

A

It is similar to G protein. When it is inactive it has a GDP bound to it. And when it is activated it is bound to a GTP. Then it can go on to phosphorylate other molecules.

96
Q

What is the phosphorylation casade?

A

One phosphorylates another. Can’t go in reverse. There are protein specific molecules?

1) changes protein activity
2) changes in gene expression

97
Q

What are the step of the NF-kB pathway?

A
  • is a protein complex that controls transcription of DNA, cytokine production and cell survival.
    1) a ligand binds to 3 receptors and causes trimerization
    2) normally in the cytosol NFKB is inactive by IKB
    3) activation triggers degradation of IKB so NFKB is active and free
    4) NFKB then translocates to the nucleus and activates gene transcription
98
Q

What is a start codon?

A

Methionine (AUG), more then one codon can code for the same amino acid

99
Q

What ‘s the reading frame?

A

3 digit codes that can be read in 3 different ways. You change the reading frame by shifting where you begin. BUUTTTTT there is only 1 open reading frame because you have to begin with AUG and the stop codon needs to be in that same reading Fram.

100
Q

What’s the structure of transfer RNA?

A
  • 3 loops: clover leaf design

Anticodon loop: matches the codon in a complementary way. Most important are D loop and T loop.

101
Q

What is the splicing of RNA?

A

In some genes the protein-coding sections of the DNA (“exons”) are interrupted by non-coding regions (“introns”). RNA splicing removes the introns from pre mRNA to produce the final set of instructions for the protein.

102
Q

What is Ca++ for?

A

Opens ions channels for chloride in salivary glands - to produce saliva

103
Q

What is receptor dimerization?

A

The principle underlying signal transduction by a tyrosine kinase receptor is that ligand binding to the extracellular domain triggers dimerization. This causes a conformational change in the cytoplasmic domain that activates the tyrosine kinase catalytic activity. - basically activates receptors.

104
Q

What is aminoacyl-tRNA?

A

amino acid that is added to the tRNA by an ester bond on the 3 prime end.

105
Q

What are ribosome domains?

A

starts by zipping along the mRNA until it finds the start codon, poly A tail helps fix the ribosome in a right way.

  • E site: exit
  • P site: peptide-tRNA binds
  • A site: aminoacyl-tRNA binds
106
Q

What are the stop codons?

A

UAA (U Ain’t going Anywhere)
UAG
UGA

107
Q

What’s the important of protein folding?

A

N-terminus is made first and C-terminus is made last. If it is folded wrong, you must trash the protein. Chaperones can help fold it correctly. If it continues to fail, the proteasome can degrade it. Can cause disease and other illnesses if folded wrongly.

108
Q

What is the function of proteasome?

A

the garbage disposal of misfolded proteins.

109
Q

What is ubiquitin and it’s pathway?

A

it’s important in getting ride of proteins we don’t want.

1) E1: ubiquitin activating enzyme: with help of ATP it gets activated
2) E2 and E3: ubiquitin ligase: E1 activates E2 and E3
3) complex then searches for a protein that is misfolded.
4) misfolded protein binds to the complex, and E1 starts adding a bund of ubiquitin to the protein and signals it to be degraded by the proteasome.

Main point is put ubiquitin on the misfiled protein so the proteasome can recognize it.

Biochem (4 decks)

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