How Cells Work (Central Dogma) pt. 1b

Question 1

An ________ (in procaryotes) consists of a promoter, genes, and a terminator

Answer 1

operon

Question 2

Initiation begins with binding of _____ to _______ region of DNA.

Answer 2

sigma factor
promoter region

Question 3

______ vary in binding affinity for the sigma factor.

Answer 3

Promotors

Question 4

When the sigma factor is released, ____ begins

Answer 4

elongation

Question 5

m-RNA synthesis stops when RNA polymerase encounters a _____ (specific sequence of bases) (can vary in strength also).

Answer 5

terminator

Question 6

_______ can be polygenic (multiple genes
controlled by one promoter).

Answer 6

Procaryotic transcription

Question 7

______ do not do polygenic messages

Answer 7

Eukaryotic

Question 8

In procaryotes, _______ occur simultaneously because they don’t have nuclear membrane.

Answer 8

transcription and translation

Question 9

m-RNA in eukaryotes can have nonsense segments, called ______.
Opposite is _____

Answer 9

introns
exon

Question 10

• m-RNA in eukaryotes undergo further _____.
• m-RNA ______.

Answer 10

processing
splicing

Question 11

_____ make it more difficult to transfer eucaryotic genes to procaryotes.

Answer 11

Introns

Question 12

Other mRNA processing steps:

• Do not occur in _____.
• ________ – 5’ end is modified by the addition of a guanine
  nucleotide with a methyl group attached.
• ______ – a string of adenine nucleotides is added to the 3’ end.

These processes are thought to increase m-RNA stability and facilitate transport across the _______.

Answer 12

prokaryotes
RNA capping
Polyadenylation
nuclear membrane

Question 13

Translation (making protein)

Three translation substeps

Answer 13

Initiation, elongation, and termination

Question 14

In prokaryotes, initiation is the formation of a _______ rRNA initiation complex

Answer 14

30s and 50s

Question 15

______ means ribosomal RNA, 30s and 50s are the sizes of
two parts of the ribosome.

If they are joined, they are called ________

Answer 15

r-RNA
70s ribosome

Question 16

Aside from that, 3 proteins called _______, and the _______ energy from GTP should also be present.

Answer 16

initiation factors
phosphate bond

Question 17

Translation: Making Proteins

In ______, m-RNA must first bind to the ribosomes

Answer 17

eukaryotes

Question 18

Translation: Making protein

All protein synthesis begins with the _____ initiation codon.

Answer 18

AUG

Question 19

_____ encodes for N-formyl methionine
(special amino acid)

Answer 19

Initial AUG

Question 20

_______ encodes regular methionine.

Answer 20

middle AUG

Question 21

________ ; ten nucleotides upstream the
initial AUG.

Answer 21

Shine-Delgarno box

Question 22

Elongation uses tRNA with attached amino acids
as _______.

Answer 22

decoders

Question 23

“____” or tRNA match the codons on
mRNA

Answer 23

anti -codons

Question 24

Three letter “words” of four possible letters (_____) form “______ on mRNA (64 possible,
many redundant).

Answer 24

UCAG
“codons”

Question 25

Process of Translation (making protein)

The _____ approaches the ribosome then the ribosome reads the _______.

Upon reading, the ribosome produces ________.

Once the 5’ enters the ribosome, the ______ helps to produce polypeptide.

Answer 25

mRNA
message
polypeptides
tRNA

Question 26

_____, _____ and _____ signals to stop

____ is the initiation

Answer 26

UAA, UAG, UGA,

AUG

Question 27

Three codons (_______) do not code for amino acids and are stop codons. Translation
stops or translation terminations sequence.

Answer 27

(UAA, UAG, and UGA)

Question 28

Translation start codon is
_____.

Answer 28

AUG

Question 29

Two sites on the ribosome for the tRNA called

Answer 29

P and A

Question 30

the ribosome is moving to balance the elongating polypeptide chain

Answer 30

Rachet mechanism

Question 31

When a nonsense codon is reached, the protein is released from the ribosome with a _______.

Answer 31

release factor

Question 32

A _____ can be read simultaneously by 10 to 20 ribosomes at once.

Answer 32

single m-RNA

Question 33

Post-translational processing:

• ______ from ribosome undergoes further processing before becoming truly useful.
• Sometimes several proteins must associate to form _______ or ________.

Answer 33

Polypeptides
enyzme or structural protein

Question 34

chaperones (proteins) that assist in ____

Answer 34

folding

Question 35

signal sequence = a sequence of 20-25 amino acids on the front of a protein that directs protein to be secreted out of the cell. The signal sequence is clipped off during ________

Answer 35

Secretion

Question 36

secretion through the cytoplasmic membrane.

Answer 36

Procaryotes:

Question 37

transport vesicles – bud around the proteins and transport to the membranes.

It can be transport thru ______, ______, or by _____

Answer 37

Eukaryotes

nuclear pores, across membranes, or by vesicles.