Chapter 15 and 16 (Test 2 Study)

Question 1

What is the name for any genes coding proteins?

Answer 1

structural genes

Question 2

What are the encoding products that interact with other sequences and affect the transcription?

Answer 2

regulatory genes

Question 3

DNA sequences that are not transcribed but play a role in regulating nucleotide sequences are ____ _____.

Answer 3

regulatory elements

Question 4

Describe constitutive expression.

Answer 4

It is continued expression under normal cellular conditions.

Question 5

Within constitutive expression, there are two type of controls. Which one inhibits gene expression and which stimulate gene expression?

Answer 5

inhibits: negative control
stimulates: positive control

Question 6

Most regulation happens at the transcription level, what is a region within DNA called? (has generally 60-90 amino acids)

Answer 6

domains

Question 7

What is the structure that fits into the major groove of DNA called?

Answer 7

motif

Question 8

Name three different types of DNA-binding proteins based on the motif.

Answer 8

• helix-turn-helix
• zinc fingers
• Leucine zipper

Question 9

What are genes controlled by a single promoter called (non-coding)?

Answer 9

operon

Question 10

What structure has products that affect the operon but are not apart of it?

Answer 10

regulator gene

Question 11

In positive transcription, the regulator protein involved is an _____.

Answer 11

activator

Question 12

What type of process uses glucose when available and represses the metabolite of other sugars?

Answer 12

catabolite repression

Question 13

In catabolite repression, which factor has a concentration that is inverse to glucose availability?

Answer 13

cAMP; cyclic AMP

Question 14

Describe an inducible operon.

Answer 14

Occurs when transcription is off and needs to be on.

Question 15

Describe a repressible operon.

Answer 15

Occurs when transcription is normally on and needs to be turned off.

Question 16

Which type of operon occurs when the control is negative and can be switched on and off?

Answer 16

negative inducible operon

Question 17

Which type of operon occurs when transcription is on and needs to be turned off?

Answer 17

negative repressible operon

Question 18

What is a small molecule that binds to the repressor and makes it capable of binding to the operator to turn off transcription?

Answer 18

corepressor

Question 19

• Has 5 structural genes
• Found in E.coli
• Is a negative repressible operon

What is it?

Answer 19

trp operon

Question 20

Which structural genes of the trp operon combine to make tryptophan?

Answer 20

trp E, trp C, trp B, and trp A = tryptophan

Question 21

(1) The ___ operon collectively works to _____ tryptophan (an amino acid).

(2) The ___ operon collectively works to _____ lactase (an amino acid).

Answer 21

(1) trp; synthesize
(2) lac; break down
‘

Question 22

_____ affects the continuation of transcription, not its initiation. This action terminates the transcription before structural genes.

Answer 22

attenuation

Question 23

List 4 characteristics or parts of attenuation.

Answer 23

• attenuator
• anti terminator
• stopping of transcription in downstream region
• uuuuuu

Question 24

What increases the rate of transcription at genes that are distant from the enhancer in bacteria?

Answer 24

bacterial enchancers

Question 25

What is complementary to the targeted partial sequence of mRNA? **This is also a way of blocking mRNAs you do not want to be translated.

Answer 25

antisense RNA

Question 26

What are the molecules that influence the formation of secondary structures in mRNA? **They form a binding site for small molecules, regulatory proteins or molecules close theses off when bonded.

Answer 26

riboswitches

Question 27

What are the mRNA molecules with catalytic activity? **When bound to small regulatory molecules, they can induce the cleavage and degradation of mRNA.

Answer 27

ribozymes (enzyme + ribosome)

Question 28

Under low osmolarity, _____ genes are created, but during high osmolarity, both _____ genes and _____ genes can also be created.

Answer 28

ompF ompF; micF

Question 29

Amino acids are joined together by ____ bonds.

Answer 29

peptide

Question 30

Label the following as either: primary structure, secondary structure, tertiary structure, quaternary structure. (1) two or more polypeptide chains associated together (2) sequence of amino acids (3) sequences of amino acids folded or pleated (DNA helix) (4) one bundle of folded amino acid sequences, condensed

Answer 30

(1) quaternary (2) primary (3) secondary (4) tertiary

Question 31

What kind of code is when an amino acid may be specified by more than one codon?

Answer 31

degenerate code

Question 32

Describe the Wobble Hypothesis.

Answer 32

Sometimes the 3rd position on the anticodon is not complementary. This results in variability and non-Watson-Crick interaction.

Question 33

Codons that specify the same amino acid are called ______ codons.

Answer 33

synonymous

Question 34

There are ___ possible codons. There are ___ stop codons. There are ___ sense codons.

Answer 34

64 3 61

Question 35

True or False: The Wobble hypothesis may exist in the pairing of a codon and anticodon.

Answer 35

True

Question 36

A polypeptide chain can be attached to a ribosome moving along the mRNA. On the polypeptide chain, which is the amino end (N) and which is the carboxyl end (C).

Answer 36

The amino end (N) is not attached to the ribosome, it is floating about. The carboxyl end (C) is attached to the ribosome.

Question 37

Where is the amino acid acceptor stem located on the tRNA?

Answer 37

At the 3’ end

Question 38

Which position is the start codon first added during elongation?

Answer 38

P

Question 39

Whenever a new tRNA anticodon attaches to the codon during elongation, which position is it added to?

Answer 39

A

Question 40

When the tRNA is expelled from the ribosome during elongation, which position is it expelled from?

Answer 40

E

Question 41

A ________ can be represented in three ways in which the sequence can be read in groups of three. Each different way of reading encodes a different amino acid sequence.

Answer 41

reading frame

Question 42

Eukaryote or Prokaryote Translation: Multi-factor, multiple step process, highly regulated and controlled.

Answer 42

eukaryotes

Question 43

Eukaryote or Prokaryote Translation: Can begin while part of the mRNA is still being transcribed, polycistronic, no nuclear membrane separating transcription and translation, Shine-Dalgarno sequence directly recruits the small subunit of the ribosome to the start codon.

Answer 43

prokaryotes

Question 44

What are the three elongation factors?

Answer 44

Tu, Ts, G

Question 45

List a few things that happen once release factors bind to the termination codon.

Answer 45

- the polypeptide releases from the last tRNA - the tRNA releases from the ribosome - The mRNA releases from the ribosome

Question 46

Different stop codons are recognized by different release factors. Because UAG is the termination codon in this illustration, the release factor is _____.

Answer 46

RF-1

Question 47

What is an mRNA with several ribosomes attached?

Answer 47

polyribosome