8c

Question 1

what is the purpose of gene expression?

Answer 1

explaining how cells decode and use the info in their gametes

Question 2

what are the 2 sequential processes that allow information encoded in genes to be copies as RNA and expressed as proteins?

Answer 2

Transcription and translation

Question 3

Explain what is meant by the “one gene–one polypeptide hypothesis,”?

Answer 3

suggests that each gene in an organism’s DNA is responsible for encoding a single polypeptide or protein.

Question 4

One gene - one enzyme (polypeptide) hypothesis was originally proposed by? and later on?

Answer 4

Archibald Garrod in 1901
beadle and Tatum(1941)

Question 5

central dogma?

Answer 5

states that genetic information flows from DNA to RNA (transcription) and then from RNA to protein (translation)

Question 6

define transcription

Answer 6

process by which the information encoded in DNA is made into a complementary RNA

Question 7

define mRNA

Answer 7

The segments of DNA transcribed into RNA molecules that can encode proteins

Question 8

Define ncRNA

Answer 8

segments of DNA copied into RNA that are not involved in encoding proteins

Question 9

define translation

Answer 9

process of synthesizing a specific protein by using the info encoded in the mRNA on a ribosome.

Question 10

_________ are building blocks of proteins?

Answer 10

polypeptides

Question 11

Most of genes are__________ into mRNA, and then the mRNA is ___________ into polypeptide.

Answer 11

transcribed
translated

Question 12

where does central dogma occurs in prokaryotes and why?

Answer 12

both transcription and translation occur in the cytoplasm due to the absence of nucleus

Question 13

where does transcription and translation occurs in eukaryotes?

Answer 13

transcription -nucleus
translation - ribosomes - rough endoplasmic membrane-cytoplasm

Question 14

define gene

Answer 14

organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA and ultimately formation of a functional product.

Question 15

what are the 4 things that a gene is composed of?

Answer 15

promoter
regulatory sequences
transcribed region
terminator

Question 16

promoter?

Answer 16

site in the DNA where RNA polymerase binds to begin transcription

Question 17

regulatory proteins

Answer 17

sites binding to regulatory proteins control whether a gene is turned on or off.

Question 18

transcribed region

Answer 18

region of a DNA that is transcribed into an RNA molecule

Question 19

terminator?

Answer 19

signals the end of gene transcription and encourages RNA polymerase to cease synthesis, releasing the transcribed RNA molecule.

Question 20

what is required for initiation of transcription?

Answer 20

transcription factors (TFs) binding to the promoter region

Question 21

function of RNA polymerase?

Answer 21

catalyzes the synthesis of RNA from a DNA template during transcription

Question 22

what facilitates binding of RNA polymerase to the promoter region?

Answer 22

Transcription factors(TRs)

Question 23

In eukaryotes, the promoter often contains a ________ box, while in prokaryotes, it includes a _________ box (________) + what’s the use of these elements

Answer 23

TATA
Pribnow box, TATAAT
help initiate and regulate the transcription of genetic information.

Question 24

in a given gene during translation how many strands a as template

Answer 24

only one aka the template strand

Question 25

how is the dna template read

Answer 25

3’ - 5’

Question 26

In what direction is the RNA synthesized

Answer 26

5’ - 3’

Question 27

what are the 3 stages of transcription

Answer 27

Transcription initiation
transcription elongation
transcription termination

Question 28

_____________ unwinds the DNA

Answer 28

RNA polymerase II

Question 29

products of transcription?

Answer 29

RNAs(mRNA,tRNA,rRNA)

Question 30

define elongation in transcription

Answer 30

where RNA polymerase reads the DNA template and sequentially adds complementary RNA nucleotides to synthesize the growing RNA chain in the 5’ to 3’ direction.

Question 31

what nucleotide incorporates thymine into RNA during elongation of transcription?

Answer 31

uracil

Question 32

where does transcription ends?

Answer 32

termination site(terminator)

Question 33

transcription ends with an _______ signal for _______.

Answer 33

AAUAAA
polyadenylation

Question 34

define polyadenylation

Answer 34

addition of a poly-A tail to the 3’ end of an mRNA molecule during transcription. This modification enhances mRNA stability and facilitates its export from the nucleus and translation in the cytoplasm.

Question 35

what are the 2 types of termination in translation?

Answer 35

1.Rho independent (intrinsic) termination
2. Rho (ATPase) dependent termination

Question 36

define, Rho (ATPase) dependent termination

Answer 36

occurs when the rho protein disassociates the RNA polymerase and moves it off of the template.

Question 37

define, Rho independent (intrinsic) termination

Answer 37

when the RNA forms a hairpin structure which displaces RNA polymerase and stops transcription.

Question 38

_________- transcription is more complex

Answer 38

eukaryotic

Question 39

what is the location of transcription in prokaryotic vs eukaryotic

Answer 39

prokaryotic- cytoplasm
eukaryotic- nucleus

Question 40

initiation of transcription in prokaryotic vc eukaryotic?

Answer 40

prokaryotic- a single sigma factor
eukaryotic- 5 generational transcriptional factors

Question 41

what type of polymerase is involved in transcription for prokaryotes vs eukaryotes?

Answer 41

prokaryotes- a single type of
eukaryotes- three types of (I, II & III)

Question 42

What is transcribed by the diff polymerase of eukaryotes?

Answer 42

RNA POLYMERASE I: transcribes RNA GENES
RNA POLYMERASE II :mRNA, miRNA, snRNA, and snoRNA genes
RNA POLYMERASE III : tRNA and 5S rRNA genes