Biology 1A03 midterm #2 review
questions with correct answers
Translation
Turning |mRNA |into |the |primary |amino |acid |sequence
Why |is |translation |so |important
determines |the |3-D |structure |of |proteins, |which |effects |their |function
Translational |components
1. |Proteins |for |initiation, |elongation |and |termination |(release |factors)
2. |tRNA, |aminoacyl |tRNA |synthetase |(charges |uncharged |tRNA |to |free |amino |acids)
3. |rRNA |and |ribosomal |proteins |(to |make |up |the |ribosomes)
Real |world |example |of |translation
antibiotics |- |work |to |treat |bacterial |infections |by |disrupting |translation |at |the |site |of |the |
ribosome
where |does |tRNA |get |the |amino |acids
they |are |delivered |to |the |tRNA |from |a |group |of |cytoplasmic |amino |acids
Overall |process |of |translation
1. |Assembly: |initation |factors
2. |delivery |of |charged |tRNA: |elongation |factors
3. |Termination: |release |factors
How |long |are |tRNA |molecules
composed |of |RNA |strands |between |70-90 |nucleotides
why |is |tRNA |complementarity |important
,- |results |in |hydrogen |bonding |between |complementary |nucleotides
- |formation |of |"clover |leaf" |structure |for |tRNA
- |entire |tRNA |folds |into |L-shape
tRNA |structure
- |clover |leaf |- |4 |segments |with |3 |loops
- |bottom |loop |is |anticodon |region
- |CCA |attachment |site
anti-codon |region |of |tRNA
forms |base |pairs |with |the |mRNA |codon |that |is |codon |for |the |protein
- |anticodons |are |written |3' |to |5'
- |takes |energy |to |bond |codon-anticodon
amino |acid |attachment |site |on |tRNA
found |at |the |3' |end, |composed |of |the |CCA |nucleotide |sequence
- |terminal |A |is |the |point |of |attachment |for |amino |acids |to |tRNA
Aminoacyl |tRNA |synthetases
family |of |enzymes |that |activate |the |tRNA |molecules |with |a |specific |amino |acid
- |specific |to |type |of |tRNA |and |amino |acid
- |binds |to |active |site |of |tRNA, |uses |ATP |to |catalyze |amino |acid |attachment |to |tRNA
how |many |tRNA |molecules |are |there |and |why?
45 |total |tRNA |molecules, |as |some |can |bind |to |more |than |one |codon
- |first |base |of |codon |always |binds |to |last |base |of |anticodon
- |third |nucleotide |has |more |flexibility |when |binding |due |to |wobble
wobble |effect
third |codon |nucleotide |can |pair |with |multiple |different |other |bases |- |helps |explain |genetic |
code |redundancy
Prokaryotic |translation |location
cytoplasm
eukaryotic |translation |location
cytoplasm
initiation |of |translation |in |eukaryotes
, occurs |when |translation |initation |complex |forms |near |5' |cap |of |mRNA, |scans |mRNA |until |AUG
intiation |of |translation |within |prokaryotes
- |translation |intiation |complex |forms |on |ribosomal |binding |sites |called |Shine-Dalgarno |
sequences
- |scans |until |it |reaches |AUG |start |codon
Shine-Dalgarno |sequences
prokaryotic |nucleotide |sequences |that |signal |the |start |of |the |translation |process |within |
prokaryotes
why |do |prokaryotes |undergo |numerous |translation |processes |on |one |mRNA
- |because |mRNA |in |prokaryotes |is |polycistronic, |which |means |it |has |multiple |functional |genes |
grouped |together |along |DNA
components |for |assembly |of |translation |in |prokaryotes |and |eukaryotes
- |two |ribosomal |subunits, |mRNA |involved, |charged |tRNA |with |methionine, |and |initiation |
factors
overall |translation |initiation |process |in |eukaryotes
- |initation |factors |bind |to |5' |cap, |recruit |small |ribosomal |subunit
- |other |initiation |factors |will |bind |the |methionine |tRNA
- |partial |complex |moves |along |mRNA |until |it |hits |AUG, |at |which |point |large |subunit |will |bind |
and |initiation |factors |release
what |are |the |two |ends |of |a |protein |called
The |N-terminal |and |the |C-terminal |ends; |or |the |amino-terminal |and |the |carboxy-terminal |ends
P-site:
holds |the |tRNA |that |contains |the |amino |acid |actively |being |translated
A-site:
Location |where |charged |tRNA |molecules |enter |ribosome
E-site
exit |site |for |tRNA |molcules
GTP-bound |elongation |factors
questions with correct answers
Translation
Turning |mRNA |into |the |primary |amino |acid |sequence
Why |is |translation |so |important
determines |the |3-D |structure |of |proteins, |which |effects |their |function
Translational |components
1. |Proteins |for |initiation, |elongation |and |termination |(release |factors)
2. |tRNA, |aminoacyl |tRNA |synthetase |(charges |uncharged |tRNA |to |free |amino |acids)
3. |rRNA |and |ribosomal |proteins |(to |make |up |the |ribosomes)
Real |world |example |of |translation
antibiotics |- |work |to |treat |bacterial |infections |by |disrupting |translation |at |the |site |of |the |
ribosome
where |does |tRNA |get |the |amino |acids
they |are |delivered |to |the |tRNA |from |a |group |of |cytoplasmic |amino |acids
Overall |process |of |translation
1. |Assembly: |initation |factors
2. |delivery |of |charged |tRNA: |elongation |factors
3. |Termination: |release |factors
How |long |are |tRNA |molecules
composed |of |RNA |strands |between |70-90 |nucleotides
why |is |tRNA |complementarity |important
,- |results |in |hydrogen |bonding |between |complementary |nucleotides
- |formation |of |"clover |leaf" |structure |for |tRNA
- |entire |tRNA |folds |into |L-shape
tRNA |structure
- |clover |leaf |- |4 |segments |with |3 |loops
- |bottom |loop |is |anticodon |region
- |CCA |attachment |site
anti-codon |region |of |tRNA
forms |base |pairs |with |the |mRNA |codon |that |is |codon |for |the |protein
- |anticodons |are |written |3' |to |5'
- |takes |energy |to |bond |codon-anticodon
amino |acid |attachment |site |on |tRNA
found |at |the |3' |end, |composed |of |the |CCA |nucleotide |sequence
- |terminal |A |is |the |point |of |attachment |for |amino |acids |to |tRNA
Aminoacyl |tRNA |synthetases
family |of |enzymes |that |activate |the |tRNA |molecules |with |a |specific |amino |acid
- |specific |to |type |of |tRNA |and |amino |acid
- |binds |to |active |site |of |tRNA, |uses |ATP |to |catalyze |amino |acid |attachment |to |tRNA
how |many |tRNA |molecules |are |there |and |why?
45 |total |tRNA |molecules, |as |some |can |bind |to |more |than |one |codon
- |first |base |of |codon |always |binds |to |last |base |of |anticodon
- |third |nucleotide |has |more |flexibility |when |binding |due |to |wobble
wobble |effect
third |codon |nucleotide |can |pair |with |multiple |different |other |bases |- |helps |explain |genetic |
code |redundancy
Prokaryotic |translation |location
cytoplasm
eukaryotic |translation |location
cytoplasm
initiation |of |translation |in |eukaryotes
, occurs |when |translation |initation |complex |forms |near |5' |cap |of |mRNA, |scans |mRNA |until |AUG
intiation |of |translation |within |prokaryotes
- |translation |intiation |complex |forms |on |ribosomal |binding |sites |called |Shine-Dalgarno |
sequences
- |scans |until |it |reaches |AUG |start |codon
Shine-Dalgarno |sequences
prokaryotic |nucleotide |sequences |that |signal |the |start |of |the |translation |process |within |
prokaryotes
why |do |prokaryotes |undergo |numerous |translation |processes |on |one |mRNA
- |because |mRNA |in |prokaryotes |is |polycistronic, |which |means |it |has |multiple |functional |genes |
grouped |together |along |DNA
components |for |assembly |of |translation |in |prokaryotes |and |eukaryotes
- |two |ribosomal |subunits, |mRNA |involved, |charged |tRNA |with |methionine, |and |initiation |
factors
overall |translation |initiation |process |in |eukaryotes
- |initation |factors |bind |to |5' |cap, |recruit |small |ribosomal |subunit
- |other |initiation |factors |will |bind |the |methionine |tRNA
- |partial |complex |moves |along |mRNA |until |it |hits |AUG, |at |which |point |large |subunit |will |bind |
and |initiation |factors |release
what |are |the |two |ends |of |a |protein |called
The |N-terminal |and |the |C-terminal |ends; |or |the |amino-terminal |and |the |carboxy-terminal |ends
P-site:
holds |the |tRNA |that |contains |the |amino |acid |actively |being |translated
A-site:
Location |where |charged |tRNA |molecules |enter |ribosome
E-site
exit |site |for |tRNA |molcules
GTP-bound |elongation |factors
