cell translation

Question 1

the major steps in info processing in bio are —– of genetic code and its —- into proteins

Answer 1

• transcription
• translation

Question 2

the products of transcription aka —- are the starting material for —–

Answer 2

• mrna
• translation
  ( gene ( dna —> rna ( mrna , trna rrna) —> translation —> protein

Question 3

—– refers to the info in mrna is trslatated into amino acids ( proteins )

Answer 3

translation

Question 4

key components of translation:
1—– template , encodes info to make proteins
2—— carrier , each amino acid brought to mrna
3—– structural anf fucntional roles of ribosomes
4- —– proteins
5- —– factors

Answer 4

• mrna
• trna
  -rrnaaaaa
• ribosomal proteins
• translation/releasing factors

Question 5

each word aka codon of the dna is consist of —-

Answer 5

3 nucleotide/bases = 1 amino acids
( we have 64 possiblikes bc we onlyy have 4 nucltodie and we have 20 amino acids )

Question 6

—- refers to the first codon in protein
— refers to the stop codon

Answer 6

• aug ( met )
• UAA

Question 7

— refers to the stating point of dna trasncprition while — is for the translation

Answer 7

• ATG
• AUG

Question 8

—- refers to a set of codons that run continuously bounded by an imitation codon and termination codon

Answer 8

open reading frame ORF

Question 9

——- is determined by which base is chosen as the start of the codon

Answer 9

reading frame

Question 10

in protein synthesis usually only — ORF contains useful info

Answer 10

one

Question 11

characteristics of the genetic code has to be:

Answer 11

1- specific: a specific codon always codes for the same aa
2- universal: applies to all species , conserved from early stages of evolution
3- reboundant: a given amino acid can be coded for by several different codons
5- non overlapping : the code is read from a fixed starting point , as continuous sequence of bases , taken 3 at a time

Question 12

true or false:
- changes in the code can cause disease
- sometimes the codon can become amplified between generations as huntigtons disease the father carries 4 copies but passes 8 copies
- each copy of the codon = extra copy of aa in the protein which can cause a misfiled protein accumulation HTT protein /gene

Answer 12

all true

Question 13

change in the codon can cause sickle cell anaemia which is the missense mutation in — gene which is a single subsitiun from —- in the codon of the amino acid — , it converts glutamic acid GAG to —- codon and its autosomal recessive

Answer 13

• b globin gene
• A to T
• amino acid 6
• valine code GTG

Question 14

—- the dictionary that translates dna sequence into amino acids

Answer 14

genetic code

Question 15

true or false:
amino acid binds to the acceptor arm , aminoacyl-trna sythetase couples amino acid to correct trna sequence
while anticodon arm base pairs w mrna sequence

Answer 15

true

Question 16

—- contains amino acid and can recognise and bind to specific codons in the mrna transcript

Answer 16

trna

Question 17

we have 50 trna matching 61 codons for 20 amino acids so trna can match to —- codon which is called —-

Answer 17

• more than one codon
• flexible pairing aka wobble which are the last 3’ base in codon on mean which binds to the first 5’ bases in anticodon in trna

Question 18

wobble base is the last — base in the codon on mrna and it binds with the first — on the anticodon of the trna
the wobble allows —– in use of trna and a single trna species carrying AA can recongzie —- condos

Answer 18

• 3’
• 5’
• efficiency/ flexibility
• 2

Question 19

—- are factories in which protein sytheiss occurs they are complexes of proteins and rna

Answer 19

ribosomes

Question 20

—- extensive secondary structuring similar to trna , ribosomal proteins interact w components of translation system

Answer 20

• rrna

Question 21

—- brings mrna and trna together to translate nuceltodie sequence of mrna into amino acid of a protein.
it has 3 main sites which are:

Answer 21

ribosomes
- A site ( aminoacyl ) : acceptor site for the next trna
- P site ( peptide ) contains the amino acid chain
- E site ( exit ) harbours deacylate trna so its uncharged , on way out of ribosomes

Question 22

the initiator trna enters through — while all others enter through the a site

Answer 22

p site

Question 23

process of translation :
1- invitation which consists of 2 parts
a. assembly of components which require for chain formation which includes :
b. recognition of the start codon by the —-

Answer 23

• 2 ribosomal subunit , mrna to be translated , trna specify by the first codon in the mrna , gap which provide energy , initiation factors that help ribosomes recognise the sequence for the start of the translation
• trna met

Question 24

—- process involves the addition of amino acids to the c- terminus aka the carboxyl end of the growing peptide chain , ribosomes will move alone mrna being translated in —– direction

Answer 24

• elnogation
• 5-3

Question 25

process of translation: 2.elongation: - next required aminoacytle-trna is delivered to a ---- site w/ the help of elongation factors - ---- bonds formed between adjacent amino acids facilitated by the enzyme ------- - after the bond is formed the ribosomes are ---- the nucleotide in the 3' direction aka to the right to the next codon . so the growing chain is moved to ---- site , uncharged trna moves to ---- site and the A site is --- to accept next trna

Answer 25

- a site -peptide bond -peptidyltransferase - translocated - p site - e site - free

Question 26

----- occurs when one of the three termination codons arrives in the a site , stops codon recognised by ---- factors , release factors bind to ---- which causes : - newly sytehsised protein to be released - diassembly of the trna-ribsome-mran complex

Answer 26

- termination - releasing - a site

Question 27

true or false: Cells are not static – need to change and adapt to environmental stimulus very rapidly

Answer 27

true

Question 28

1-the regulating protein levels mechanism: 2.how can we regulate protein activity:

Answer 28

1a- increased transcprtion/ translation enhances levels 1b- degradation removes protein when function complete or damaged - * Protein levels * Protein location and concentration * Ligand Binding * Cofactor requirements. Eg: Ca2+ or GTP * Post-translational modifications

Question 29

---- is a normal process that ensures a protein fit for a purpose but its also a mechanism that can be used to --- a pathway , --- activity or -- a process

Answer 29

- protein turnover - shut off - reduce - stop

Question 30

proteins with a key ----- often rapidly turned over or degraded to keep the, under tight regulation

Answer 30

regulatory functions

Question 31

proteins get degraded when : 1-------- turnover which refers to the housekeeping proteins get damaged and need replacing or the misfiled proteins need to be recycled 2- ----- is when the levels of proteins tightly regulated to control fucntion as cyclins are synthesised to promote entry into cell cycle and rare degraded when want to turn them off also it occurs in the course of being activated some proteins get cleaved and need to be replaced as : digestive enzymes that are secreted as zymogens

Answer 31

1- normal protein turnover 2- dynamic process - turning on/off highly regulated

Question 32

---- degrades proteins that are imported into the cells and is not specific ---- degrades systolic proteins marked for destruction

Answer 32

1- lysosomal degradation 2- proteasomal degradation

Question 33

---- protects the cytosolic proteins from activities if they leak out and they degrade any biological material as protein nucleic acid carbs lipid

Answer 33

lysosomes pr

Question 34

---- when proteins are labeled or tagged for degradation

Answer 34

‘polyubiquitination’ aka in proteasomal degradation and it targets protein that is rcohnzied

Question 35

-----a multiprotein, barrel shaped complex containing protease enzymes *Found in the nucleus or cytoplasm *Same basic composition all sub-types and same function – protein degradation

Answer 35

protesome

Question 36

Common post-translational modifications (PTMs):

Answer 36

– Ligand binding – Phosphorylation – Cleavage to produce active protein/enzyme – Ubiquitination – Fatty acid modification/ lipidation – Glycosylation

Question 37

---- changes the shape of protein , active conformation , release of inhibitory subunits and change of cell location as: steroid hormone binding their ligands, gets conformational change m now dimerise and enters the nucleas

Answer 37

ligand binding

Question 38

Zymogens – pro-enzymes Cleavage of pro-enzymes activates refers to:

Answer 38

proteolytic cleavage

Question 39

reversible phosphorylation of proteins: - phsosphate group added to ------ and their ratios are: ----- mat be least abundant but has the most effect

Answer 39

- serine:theronine:tyrosine S:T: Y - ratios : 100:10:1 - trysoine

Question 40

in reversible phosphorylation of proteins they are very --- regulated and ----- added to phosphate and ---- remove it

Answer 40

- tightly - kinasase - phosphatase

Question 41

fucntions of phosphorylation :

Answer 41

- alters protein function - marks for degradation - alters localisation - promotes interactions ( check slide 37 + 38 plsssss)