Amino acid and protein synthesis test 3 Flashcards Preview

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Flashcards in Amino acid and protein synthesis test 3 Deck (42):
1

AA biosynthesis from alpha ketogluterate

glutamate
glutamine
proline
arginine

2

AA biosynthesis from 3-phosphoglycerate?

serine
glycine
cysteine

3

AA biosynthesis from oxaloacetate

aspartate
asparagine
methionine
threonine
lysine

4

AA biosynthesis from pyruvate

alanine
valine
leucine
isoluecine

5

AA biosynthesis from phosphenolpyruvate and erythrose 4-phosphate

tryptophan
phenylalanine
tyrosine

6

AA biosynthesis from ribose-5-phosphate

histidine

7

T/F DNA is primarily in the nucleosome form?

true

8

what is an intron and exon?

introns are non-coding
exons are coding for AAs

9

All the DNA in mammals codes for proteins T/F?

false only 1.5% codes for proteins
25,000 human genes

10

what is the regulatory/silencer region of DNA?

binding of proteins that promote or inhibit transcription

11

what is the promoter region of DNA?

transcription factor and RNA polymerase binding site

12

what is the open reading frame?

AA encoding region containing introns and exons

13

what is the UTR?

untranslated regions necessary for RNA processing

14

RNA polymerase I

synthesizes ribosomal RNA or rRNA

15

RNA polymerase II

synthesis messenger RNA or mRNA

16

RNA polymerase III

synthesis of transfer RNA tRNA

17

how is DNA read by the RNA polymerase?

read 3'-5'
made 5'-3' (same as non template DNA)

18

what initiates DNA binding of RNA polymerase?

transcription factor complexes

19

Negative regulation of DNA transcription

-molecular signal causes repressor to move from operator region
-molecular signal binds with free repressor which then binds to operator region to inhibit transcription

20

positive regulation of DNA transcription

-enhancement can occur with the removal of an activator(allow binding of RNA polymerase)
-or the binding of an activator(stabilize RNA polymerase)

21

what are the Three RNA processing steps?

addition of 5' cap
intron splicing
addition of poly A tail
**this is in order of how this happens

22

what is the purpose of the 5' cap?

-protects mRNA
-binds to ribosomes to initiate transcription
-tethers mRNA until translation is complete

23

mRNA splicing

-four classes of introns
-two are self splicing
-most introns are not self splicing and require a spliceosomes.
-introns are released into nuclear space and degraded

24

how does splicing lead to more protein diversity?

because splicing happens at different places depending on where it is produced
-thus 1 gene=more than one protein

25

Termination and Poly A tail

AAUAAA upstream sequence
G and U rich residues downstream
protects mRNA tail
Anchors mRNA during translation
**occurs independent of RNA polymerase

26

how does mRNA get out of the nucleus?

binding of protein factors bring the mRNA to nuclear pore and then go off to translation

27

where are the two domains of translation

in the cytosol
and in RER membrane

28

what is the importance of inosinate?

it is very promiscuous and allows for variance in the 3rd codon and allows for resistance to mutation.

29

what are the five steps in translation?

activation of AAs
initiation
elongation
termination
protein folding

30

what occurs in activation

aminoacylating tRNAs (putting the AA on the tRNA)

31

what occurs in initiation

-initiation factors bind to 5'
-recruit 40s ribosome complex, which scans mRNA for start codon and the anticodon binds.
-poly A tail and 5' keep mRNA in place
-then the large 60s ribosome binds
**ATP/GTP hydrolysis drives initiation

32

elongation at the ribosome

-mRNA is read 5'-3' (opposite of RNA polym)
-aminoacyl, peptidyl, and exit sites of large ribosome subunit (APE)
-poly pep chain is made N->C terminus

33

termination

termination factor causes release

34

proteins made at the endoplasmic reticulum are what kind?

integral membrane proteins
intravesicular proteins
secreted proteins
-primary site of protein modification

35

what is the Signal Recognition Particle cycle?

the SRP on the ER causes the ribosome to associate and make the protein into that site at the RER.
-GTP dependent

36

post-translational modifications that occur within the ER

protein folding
proteolytic cleavage
-glycosylation
-acetylation
-phosphorylation
-methylation
-acylation

37

proteins made at the ER are what kind. (3) of them

integral membrane proteins
intravesicular proteins
secreted proteins

38

proteins made in the cytoplasmic space are what kind (3) types

nuclear proteins
structurally associated proteins
membrane-associated proteins

39

how do proteins get into the nucleus?

because they have a nuclear localization sequence on them that recruits other proteins that bring that protein into the nucleus

40

what targets a protein for degradation?

polyubiquitination tags a protein for destruction

41

proteosome degrade what kind of proteins?

degrades cytoplasmic proteins

42

lysosomes degrade what kind of proteins?

degrades vesicular and membrane proteins
*proteins made in the ER