Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BI203 > Midterm #3 > Flashcards

Midterm #3 Flashcards

1
Q

what are codons

A

nucleotide sequence triplets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the start codon/amino acid?

A

AUG - methionine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the stop codons

A

UAA, UAG, UGA - dont code for an amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the untranslated regions (UTR) of mRNA?

A

the 5’ and 3’ end of the mRNA that are not translated into proteins (5’ UTR and 3’ UTR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is tRNA?

A

transfer RNA - carries amino acid to ribosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is an open reading frame?

A

the region of mRNA that codes for amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are aminoacyl tRNA synthestases?

A

enzymes that attach amino acids to tRNA - specific to amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a charged tRNA?

A

a tRNA with an amino acid attached

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the wobble hypothesis?

A

the idea that the base on the first position on the tRNA (5’ end) is usually an abnormal base like inosine, pseudouridine, tyrosine etc, which can pair with multiple nitrogenous bases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the function of the large subunit of the ribosome?

A

aids in the formation of peptide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

which genes code for the large subunit of the ribosome?

A

28s, 18s, 5.8s genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the gene that codes for the small subunit of the ribosome?

A

5s genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the function of the small subunit of the ribosome?

A

recognition of the translation start site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the differences between prokaryotic and eukaryotic mRNA in translation?

A

Prokaryotes:
- polycistronic = has multiple protein coding genes per mRNA transcript
- no mRNA transport out of nucleus
- has multiple translation start sites

Eukaryotes:
- monocistronic = has only one protein coding gene per mRNA transcript
- mRNA transport out of nucleus and into cytosol where translation occurs
- only has one translation start site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is initiation in translation?

A

when the ribosome binds at the 5’ UTR and initiates polypeptide synthesis at the start site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how do prokaryotes signal for translation initiation?

A

uses shine dalgarno sequence to signal translation start site - small subunit has a complementary sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how to eukaryotes signal for translation initiation?

A

ribosome scanning = small subunit of scans mRNA until it finds an AUG to initiate translation - requires ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are eukaryotic initiation factors (eIFs)?

A

proteins that help aid and initiate translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the different eIFs?

A

eIF2, eIF4E, and Poly-A binding protein (PABP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the function of eIF2?

A

recognizes the tRNA for methionine (AUG) and binds the initiator methionyl-tRNA (translation cant start w/o methionine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the function of eIF4E?

A

recognizes and binds to the 5’ methyl cap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the function of the poly-A binding protein (PABP)?

A

binds to the poly-A tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are internal ribosome entry sites?

A

sites where translation can be initiated independent of the 5’ methyl cap - shortcut

23
Q

what is elongation in translation?

A

the building of the polypeptide chain by the ribosome

24
Q

what are eukaryotic elongation factors (eEFs)?

A

proteins that aid in elongation

25
Q

what happens in the P(peptide) site of the ribosome?

A

where the amino aid chain is located and grows

26
Q

what happens in the A (aminoacyl site) of the ribosome?

A

where the subsequent amino acids/tRNAs are brought in

27
Q

what happens in the E (exit) site of the ribosome

A

where the tRNA exits the ribosome?

28
Q

what are the different eEFs?

A

eEF1α and eEF2

29
Q

what is the function of eEF1α?

A

brings in the new tRNA/amino acids into the A site of the ribosome

30
Q

what is the function of eEF2?

A

moves the tRNA between the ribosome sites

31
Q

what is termination of translation?

A

the end of translation

32
Q

what happens during termination of translation?

A

release factors (proteins that release the polypeptide chain and mRNA from the ribosome) recognize the stop codon sequence and, releases the mRNA, and the ribosome dissociates

33
Q

what are chaperone proteins?

A

proteins that facilitate the folding of the proteins by recognizing hydrophobic residues

34
Q

what are chaperonins?

A

chaperone proteins that provide an isolated environment within which correct folding takes place

35
Q

what is protein disulfide isomerase (PDI)?

A

an enzyme that recognizes cystine residues and adds disulfide bonds

36
Q

what is peptidyl prolly isomerase?

A

an enzyme that recognizes proline residues and twists them into the trans conformation

37
Q

what is proteolytic processing?

A

removing sections of polypeptides in order to activate the protein

38
Q

what are glycoproteins?

A

proteins with carbs attached to them

39
Q

what is the function of glycoproteins?

A

protein folding in the ER, targeting proteins for transport, and cell-cell recognition

40
Q

what are GTPase activating proteins (GAP)?

A

activates the activity of GTPase - makes hydrolysis happen faster

41
Q

what are guanine exchange factors (GEF)?

A

protein that transforms GTP to GDP

42
Q

what are kinases?

A

enzymes that add a phosphate group

43
Q

what are phosphatases?

A

enzymes that remove phosphate groups

44
Q

what is the proteasome?

A

trash compactor that breaks down misfiled proteins

45
Q

what is the nuclear lamina?

A

a cytoskeletal structural complex composed of lamin proteins (intermediate filaments)

46
Q

what is the nuclear pore complex?

A

channels for all transport in and out of nucleus

47
Q

what are the two modes of passage in and out of the nuclear pore complex?

A
  1. Passive diffusion = fiddusion with no energy involved (goes down concentration gradient)
  2. energy dependent transport - mode of transport for most proteins and RNA
48
Q

what is a nuclear localization signal (NLS)?

A

signals that specific protein needs to be brought into the nucleus

49
Q

what are importins?

A

a family of receptors that bind to the NLS and transport proteins into the nucleus

50
Q

what is Ran?

A

GTP binding protein

51
Q

what are the steps of importing transport with Ran?

A
  1. importin binds to the NLS and transports the cargo protein through the nuclear pore complex
  2. Ran/GTP (activated Ran) binds to the importin and dislodges the cargo protein
  3. Ran/GTP transports importin out of the nucleus
  4. Conversion of Ran/GTP to Ran/GDP by RanGAP releases importin
52
Q

what is an exportin?

A

a family of receptors that binds to the NES (nuclear export signal) and transports proteins out of the nucleus

53
Q

what are the steps exporting proteins with Ran?

A
  1. NES of proteins bound for export is recognized by Ran/GTP
  2. binding of Ran/GTP stabilizes the complex and transports it out of the nucleus
  3. conversion of Ran/GTP to Ran/GDP by RanGAP releases cargo protein
54
Q
A

BI203 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions