18. Gene Expression

Question 1

Nuclei can acid transmit and help EXPRESS hereditary info. What express??

Answer 1

It means DNA =transcribed and translated to production of protein

Question 2

Enzyme that initiates transcription is

Answer 2

RNA polymerase

Question 3

Enzyme catalysed synthesis of new DNA molecule

Answer 3

DNA polymerase

Question 4

Assembly of transcription factors on promoter begins some 25 nucleotides upstream where it binds to start a WHAT sequence

Answer 4

TATA

Question 5

In order for gene to be transcribed RNA polymerase must have access to the DNA helix and be able to bind the genes

Answer 5

Promoter

Question 6

Eukaryotic mRNA transcripts are protected from modification by

Answer 6

5’ caps

Question 7

Process of WHAT cuts introns from primary transcript and The final processed mRNA is produced

Answer 7

RNA splicing

Question 8

Are genes composed of extra segments (of non essential material) called expand??

Answer 8

NOO

Question 9

tRNA a function

Answer 9

Pick up fee amino acids in cytoplasm

Question 10

What is transcription?

Answer 10

The making of RNA from DNA

Question 11

What is translation?

Answer 11

The making of PROTEIN from RNA

Question 12

State cellular compartment where transcription and translation take place in

Answer 12

PRO CELL: cytoplasm = transcription+ translation

EUKARYOTIC:

1. Nucleus=transcription +RNA processing /splicing
2. CYTOPLASM= translation

Question 13

mRNA

Answer 13

1. Is transcribed from DNA segment and gene

2. CARRIES msg of gene to RIBOSOME for translation

Question 14

RRNA

Answer 14

part of ribosomes

1. The site that TRANSLATES the mRNA INTO PROTEIN SEQUENCE

Question 15

TRNA

Answer 15

Carries INDIVIDUAL AMINO ACIDS into

Ribosomes for synthesising a protein

Question 16

Which strand of DNA = used as TEMPLATES for making mRNA transcript???

Answer 16

Template strand 3’-5’

Question 17

Understand reason why non template strand is known as coding strand

Answer 17

Coding strand contains codons.
Template contains anticodons.

Coding strand= DNA strand that has SAME BASE SEQUENCE as RNA transcript Provided ( however t replace u)

Question 18

Write mRNA SEQUENCE when DNA sequence is provided
3’-5’: ACCAAACC (CODING STRAND)
5’-3’:TGGTTTGG (TEMPLATE STRAND)

Answer 18

mRNA

1. Copy template strand of DNA
2. Change t to u

5’-3’: UGGUUUGG

Question 19

How many nucleotide bases for 1 amino acid??

Answer 19

3 nucleotide bases in DNA code for 1 amino acid ( TRIPLET CODE)

Question 20

What is maximum possible number of amino acids that can be formed?

Answer 20

64 ( more than enough to code 20 amino acids! Of

Question 21

Which could don is always the start codon?

Answer 21

AUG

Question 22

What does DEGENERATE mean

Answer 22

Feature of genetic code.When there is more than one possible codon for one particular amino acid.

Question 23

Genetic changes de is universal. Define..

Answer 23

All organisms can use ACTG in gene expression

Question 24

Understand concept of reading frame

Answer 24

Reading fram= est. frm 1st codon, determines the reading of all subsequent codons. Occurs w/o punctuation and overlapping.

Read each triplet code

Question 25

What is functional role of promoter in transcription ??

Answer 25

RNA polymerase binds to promoter

Question 26

What does (+1) in the start site mean???

Answer 26

Means this is the first BASE to be transcribed

Question 27

There are 6- base sequences common to PROKARYOTIC promoters. One is located at -35 and at -10. What does -35 and -19 mean??

Answer 27

Means they are located 10&35 nucleotide bases upstream of the site

Question 28

We understand that first nucleotide to be transcribed is at (+1) position. However where does DNA become unwond???

Answer 28

At the -10 site

Question 29

What is the synthesis direction of RNA?

Answer 29

From 5'-3' direction as ribonucleotides are added to growing RNA chain

Question 30

What are common terminated sequences?

Answer 30

A series of GC base pairs followed by at Base pairs

Question 31

What would base pairs of terminator sequence (GC Followed by AT base pairs) form?

Answer 31

A double strand structure called a hair pin

Question 32

PROKARYOTIC transcription and translation can always occur at same time but not in ecell gene expressi n. Whyyy

Answer 32

B/c the two processes occur in diff places in E CELL NUCLEUS- transcription and splicing CYTO: Translation

Question 33

What are two unique features of promoter in eukaryotic cell structure??

Answer 33

1. Includes a TATA box( nucleotide sequence w/ TATAR about 25 nucleotides upstream from transcription starting point. 2. E PROMOTER& RNA POLYMERASE INITIATION OF TRANSCRIPTION- Require series of transcription factor

Question 34

Pre MRNA has two ends

Answer 34

1. 5' cap | 2. Poly A tail

Question 35

MATURE RNA has 4 ends

Answer 35

1. 5' Cap 2. 5' UTR 3. 3' UTR 4. Poly A tail

Question 36

Define UTR

Answer 36

Untranslated region (5 & 3' UTR) in mature RNA to regulate translation activity

Question 37

What is process that modifies eukaryotic mRNA transcripts??

Answer 37

RNA splicing

Question 38

Splisosomes are req for modifying the mRNA transcripts. What do enzyme do they contain?? State 2 function they perform

Answer 38

Ribozymes which catalysed : 1. Cutting of INTRONS on pre mRN 2. Splicing together of EXTRONSk releasing introns for rapid degradation

Question 39

Where dos translation take place??

Answer 39

Right in cytoplasm

Question 40

Advantage of having translation of poly ribosomes

Answer 40

Enhance speed of translation

Question 41

State where post translational ,doi fixation take place in cell

Answer 41

Golgi apparatus

Question 42

Using glycoproteins as an example describe what post translational modification has done

Answer 42

Glycoproteins, add glucose to protein