2e AND 2F

Question 1

exocytosis

Answer 1

the cells excrete waste and large molecules from the cytoplasm to the exteriorenvironment via vesicle

Question 2

differnece between golgi body and RER

Answer 2

golgi body packages proteins inot vesciles, whislt RER modifies protiens

Question 3

Once proteins are produced and modified, what happens to the proteins

Answer 3

the proteins are packaged into a vesicle and released out of the cell via exocyotisis

Question 4

What type of transport is exocytosis and is ATP required

Answer 4

exocystosis is a form of bulk transport and requires ATP

Question 5

Process of exocytosis

Answer 5

1. Vesicle is transported to the plasma membrane
2. Vesicle fuses with the plasma membrane
3. contents of the plasma membrane is released from the cell into the extracelluar environment

Question 6

Whatt triplet base sequence repersents tryptophan

Answer 6

UGG codes for tryptophan

Question 7

What is the process of attenuation when tryptophan is present on the tRNA molecule

Answer 7

1. transcription and translation occurs at the same same
2. when ribsokmes reach the UGG code for tripytophan, tryptophan attaches to polypeptide chain,tRNA
3. Ribsoomes reach STOP codon, RNA polyermase continues to read the DNA, however ribosomes stop translating the mRNA

4.but at the same time domain 3&4 pull away and form a hairpin

5. Thereofre RNA polyermase stops reading dna after the attenuated region

Question 8

How is bacteira, E.Coli responsible for transcribing genres involved in making tryptophan

Answer 8

In E. coli, the trp operon regulates the transcription of genes involved in tryptophan synthesis. When tryptophan levels are low, the operon is activated, allowing for gene transcription and subsequent tryptophan production.

Question 9

Process of attenuation when tryptophan is absent on the tRNA molecule

Answer 9

1. transcription and translation happen at the same time

2.ribosomes pause at the two tryptophan codons because its waiting for tryptophan

3. During that pause domain 2 and domain 3 form a loop, which stops domain 3 & 4 from pairing.
4. This allows RNA polyermase to still attach to the 4th domain, and continue to transcribe the trp operon genes, thus making more trytophan, which is known as attenuation.

Question 10

between what domains is there a pause of trp production

Answer 10

between domain 2 and 3, hwoever there is no pause betewen seciton 3 and 4

thisis because the pause between domain 2 and 3 allows for the attenutation mechanism to occur. However, there is no pause between domain 3 and 4 because they are not involved in attenutation mechanism because they have the genes for tryptophan production.

Question 11

complete process of transcription in gene expression

Answer 11

1. Inititation:
   Transcription factors bind to the promotor region to intitate transcription

RNA polymerase binds to the promotor region whihc signals to the weak hydrogen bonds between the DNA to break

This results in the bases of DNA to be exposed

2. Elongation:
   RNA polymerase moves along the template strand of the DNA in a 3’ to 5’ end direction

As it moves along, the complemenatry RNA nucleotides are added to produce a pre-mRNA molecule

Termination:
Transcription ends when RNA polymerase reaches the termination sequence

This signals to the premRNA molecule to be released for processing

DNA winds up and hydrogen bonds form between the strands

Question 12

full process of translation in gene expression

Answer 12

1. Initation:
   the 5’ end of the mRNA molecule attaches to the ribosomes

The start codon(AUG) is read then the tRNA molecule with complementary anticodon(UAC) binds to the ribsoomes to deliever the amino acid to methione

2. Elongation:
   The next codon is read and the complementary tRNA molecule delivers a specific amino acid to the ribosomes

This amino acid will bind to the adjacent amino acid from the peptide bond

This process continues and a growing polypeptide chain of amino acids are produced.

3. Termination:

Once the stop codon is read, this signals the end of translation

Since there is no tRNA moleucle that corresponds to the STOP codon,

instead, A release factor binds to release the polypeptide chain of amino acids for modification

Question 13

attenuation mechanism

Answer 13

attenuation mechanisms can refer to processes by which gene expression is regulated, often involving the repression of transcription or translation, leading to a decrease in the production of tryptophan.

Question 14

trp operon

Answer 14

seriesof genes responsible for the production of the amino acid tryptophan,

Question 15

examples of each of the structures

Question 16

hydroge n onds

Answer 16

attrction etween ocxygen and hydrohgen and form between the complementary nitrongoeus basess of DNA

Question 17

open reading frame

Answer 17

section of the gene that is being coded into mRNA

Question 18

tata box is

Answer 18

sequenceof the promtor region that indicates where a genetic sequence can be read and decoded

Question 19

sequence of a gene

Answer 19

promotor –> operator –> leader –> trp genes (coding region)

Question 20

function of coding genes and non coding regions

Answer 20

Coding genes contain instructions for making proteins, while non-coding regions regulate gene expression and maintain genome stability.

Question 21

in the trp opern, there is 1 coding region, with 5 structural genes, what are they and what do they do

Answer 21

collecitvley these trp structural genes make up parts of the enzyme and involved in the production tryptophan

Question 22

where is trp opern produced

Answer 22

E.coli which is a prokaryote

Question 23

why does attenutation more likely to occur E.coli/prokaryotes

Answer 23

since the prokaryotes dont have a nucleus, the transcription and translation occurs occur simulataneously and close together
unlike the eukaryotes in which transcription occurs inside the nucleus whereas translation occurs outside the nucleus

Question 23

compare attenuation and repression

Answer 23

in trp operon repression transcription does not occur, but in trp opern attenuation transcription begins but stops before a protein is produced.

in trp operon repression, the operator region is the most importat secitionbc its where the repressor bind to, but in trp operon attenutation is the leader region isthe most importnat because its where the leader sequence is

Question 24

leader sequence is important because

Answer 24

, the leader sequence helps control how much tryptophan the cell makes by stopping the production of trp structueal genes when it’s not needed.

Question 25

protein secretorty pathway- what isexplain

Answer 25

The protein secretory pathway is a cellular process responsible for synthesizing, modifying, and transporting proteins to their final destinations within or outside the cell.

Question 26

why does transcription and tranlsation occur at the sametime

Answer 26

, in prokaryoteslike some cells like bacteria, transcription (making RNA from DNA) and translation (making proteins from RNA) happen at the same time because the cell doesn’t have a separate compartment for these processes.

Question 27

what does RNA polyemerse do

Answer 27

bindto DNA tomakes mRNA

Question 28

process of protein secretorty pathway

Answer 28

The protein secretory pathway involves proteis being produced in the ribosomes. These proteins, either stay in the cytoplasm or being directed to the Rough endoplasmic reticulum (ER) for folding and modification before being transported to the Golgi apparatus for further be packaged into vesicles, which deliver proteins to be transported out of the cell via exoctyosis.

Question 29

compare transcirption vs translation

Answer 29

transcription isthe process wherbey DNA is made into RNA

Translation isthe process where by RNA is made into proteins

Question 30

outline the process of transcription

Answer 30

Transcription begins with the unwinding of DNA at the promoter region. RNA polymerase catalyzes the synthesis of a complementary RNA strand, using the DNA template strand. This newly synthesized RNA, called pre-mRNA, is complementary to the DNA template and includes adenine pairing with uracil instead of thymine. Transcription terminates when RNA polymerase reaches thetermination sequence in DNA.

Question 31

3 main steps of gene expression state

Answer 31

transcription

RNA processing

Translation

Question 32

outline the process of tranlsation

Answer 32

Translation begins with initiation where the5’ end of the mRNA binding to ribosomes. Then followed by the complemeanatrytRNA molecule attaches to the start codon. During elongation, the ribosome moves along the mRNA,by matching tRNA anticodons with mRNA codons and forming peptide bonds between amino acids. Termination occurs when the stop codon is read, polypeptide chain of amino acids is released.

Question 33

repressor gene and represosr protein.

Question 34

premRNA is characterised by

Answer 34

introns and exons

Question 35

where is RNA found

Answer 35

free in ribosomes or cytoplasm

Question 36

comparing the bonds between Adenine and thymine and cytosine and guianaien

Answer 36

adenine and thymine has weaker bonds bceause it has 2 hydrogen bonds, whereas cytosine andguanine are stronger because they have 3 hydrogenbonds

Question 37

how is DNA and RNA associated to nucleotides

Answer 37

DNA and RNA are polymers of nucleic acids.

Question 38

how are nucleic acids built

Answer 38

by DNA/RNA polyermease in a 3’ to 5’ direction.

Question 39

how many base pairs of a double helix form per twise

Answer 39

10.5 bp base pairs per twist

Question 40

where is the promotor region found

Answer 40

at the 5’ end of the gene.

Question 41

what does RNA polyermease do at the templatestrand/non coding region

Answer 41

RNA polyermase pairs RNA nucloetides with complemmenatry bases on the non coding strand of the DNA.

Question 42

genetic code is said to be degenerate means

Answer 42

amino acids are encoded by more than one mRNA codon

Question 43

cargo proteins

Answer 43

Any protein that is carried within the vesicles of a cell’s secretory system