Module 33

Question 1

Purpose of DNA Replication

Answer 1

Allows genetic information to be transmitted from cell to cell AND generation to generation

Question 2

How is information transmitted from DNA

Answer 2

When the double helix separates and each parental strand serves as a template.

Question 3

Central Dogma of molecular biology

Answer 3

The flow from DNA to RNA to proteins.

Question 4

Transcription

Answer 4

1st step of gene expression
When RNA is synthesized from a DNA template

Question 5

Where are proteins synthesized

Answer 5

On ribosomes

Question 6

Where are ribosomes located

Answer 6

in the cytoplasm

Question 7

Template Strand

Answer 7

The DNA strand that is used as the model for the synthesis of an RNA transcript

Question 8

RNA polymerase

Answer 8

The enzyme that synthesizes new RNA molecules from DNA

It does so at the 3’ end of the RNA strand

Question 9

Why does RNA need its own synthesis enzyme

Answer 9

Since RNA contains Uracil instead of Thymine

Question 10

Growing Transcript

Answer 10

The 3’ end of the newly synthesized RNA molecule

Question 11

Describe the RNA trancript

Answer 11

The reverse complement of the template strand

Question 12

What causes RNA to be the reverse complement of its template

Answer 12

RNA grows in the opposite direction that DNA is read in (antiparallel)

The base paring rules= complementary strands

Question 13

Nontemplate Strand

Answer 13

The DNA strand that is not used as the template for transcription

The same as the new RNA strand
-Same bases and direction
- Also a reverse complement of the template strand

Question 14

Which strand can also be called the minus, antisense or noncoding strand

Answer 14

the template strand

Question 15

Three stages of transcription

Answer 15

1. initiation
2. elongation
3. termination

Question 16

Initiation stage

Answer 16

RNA polymerase and other proteins bind to the double-stranded DNA, the strands separate, and the transcription of the template strand begins

Question 17

Elongation Stage

Answer 17

Successive nucleotides are added in the 3’ direction of the growing RNA transcript as the RNA polymerase proceeds along the template strand

Question 18

Termination

Answer 18

RNA polymerase encounters a sequence in the template strand that will cause the transcription to stop and the RNA transcript to be released.

Question 19

Promoter

Answer 19

regions of a few hundred base pairs on the DNA molecule where RNA polymerase and other proteins bind to start transcription

Question 20

Terminator

Answer 20

Sequence on DNA strand where transcription stops

Question 21

How man DNA strands are transcribed per gene

Answer 21

Only one DNA strand is transcribed per gene

Question 22

Do all genes come from the same template strand

Answer 22

No. Different strands can be used to transcribe different genes

Question 23

What are other names for the non-template strand

Answer 23

Coding, sense and plus strand

Question 24

In what type of cells can transcription occur at all times

Answer 24

House keeping genes

Question 25

Why can transcription occur at all times for housekeeping genes

Answer 25

Since their products are needed at all times in all cells.

Question 26

How is transcription regulated

Answer 26

It depends on whether the RNA polymerase and associated proteins are able to bind with the PROMOTER

Question 27

What direction is RNA synthesized in

Answer 27

5' to 3' end

Question 28

In what direction does RNA polymerase move along the DNA strand

Answer 28

3' to 5'

Question 29

RNA polymerization

Answer 29

Another name for RNA synthesis

Question 30

Does RNA proof read

Answer 30

No.

Question 31

RNA polymerase purposes 5

Answer 31

1. Separates DNA strands from each other 2. Forms RNA-DNA molecule 3. Elongates transcript 4. Releases the transcript 5. Stores OG DNA double helix

Question 32

Bond connecting one phosphate t the next

Answer 32

Phosphate bond

Question 33

Phosphodiester Bond

Answer 33

Attaches the 3' end of the growing chain to the income nucleotide Forms the sugar-phosphate backbone 3' -OH to the 5' carbon of the nucleotide

Question 34

Primary Transcript

Answer 34

The RNA transcript that comes off the template DNA strand

Question 35

Messenger RNA (mature) mRNA

Answer 35

The RNA molecule that combines with the ribosome to direct protein synthesis Carries the genetic "message" from DNA to ribosome

Question 36

RNA Processing

Answer 36

When the primary transcript undergoes a series of chemical modifications that convert it into mRNA

Question 37

What kind of RNA is transcribed from DNA in prokaryotes

Answer 37

mRNA

Question 38

In which type of cell does RNA processing not occur

Answer 38

Prokaryotic cells

Question 39

From what end do ribosomes synthesis proteins

Answer 39

the 5' end of mRNA

Question 40

Why does transcription and translation occur at the same place and time in prokaryotes

Answer 40

They do not have a nucleus to separate the DNA from the cytoplasm

Question 41

When does the primary transcript become mRNA in eukaryotes

Answer 41

Before exiting the nucleus

Question 42

What other feature does prokaryotic RNA have that DNA doesn't

Answer 42

They can often have the genetic info for more than one different protein

Question 43

GTP Cap

Answer 43

A modified nucleotide (7-methylguanosine) attaches to the 5' end of the primary transcript The 5' carbon links with the 5' carbon of the two nucleotides -Added with an enzyme -Instead of a phosphodiester bond

Question 44

Purpose of the GTP Cap and when is it added

Answer 44

Added during RNA processing Allows the ribosome to recognize the mRNA

Question 45

Why is RNA susceptible to enzymes that break them down

Answer 45

Their single-stranded structure

Question 46

Poly(A) tails purpose

Answer 46

Help export the mRNA into the cytoplasam

Question 47

Poly(A) tail

Answer 47

250 consecutive adenine nucleotides added to the 3' end of the transcript

Question 48

Exons

Answer 48

Regions of the transcript expressed as proteins

Question 49

Introns

Answer 49

Regions of the transcript not expressed as proteins and are REMOVED from the primary transcript

Question 50

When are introns remvoed

Answer 50

during RNA processing

Question 51

What is it called when exons are stitched together and introns are removed

Answer 51

RNA splicing

Question 52

Purpose of introns

Answer 52

Alternative splicing

Question 53

Alternative Splicing

Answer 53

Primary transcripts from the SAME GENE are spliced in different ways to produce different mRNA's and, therefore, DIFFERENT/MULTIPLE PROTEINS products Allows the same transcript to be processed in diverse ways to produce mRNA molecules with different combos of exons, encoding different proteins

Question 54

Ribosome RNA (rRNA)

Answer 54

Noncoding RNA It makes up most of the ribosomes and is essential for translation

Question 55

Nucleolus

Answer 55

dense, non-membrane-bound spherical structure within the nucleus

Question 56

Houses the genes and transcripts for rRNA

Answer 56

nucleolus

Question 57

Transfer RNA (tRNA)

Answer 57

Carries individual Amino Acids for use in translation

Question 58

Most abundant types of RNA molecules in mammals w/ percents

Answer 58

rRNA (80%) of RNA tRNA (10%) of RNA