Biol 205

Question 1

What is the coding strand?

Answer 1

Sense strand (+ strand)
Has the same sequence as the mRNA

Question 2

What is the template strand?

Answer 2

The non coding strand
Used to synthesized mRNA
Opposite of coding and mRNA strand

Question 3

What is a codon?

Answer 3

Three letter code specific to the genetic code

Question 4

What is the tRNA?

Answer 4

Type of RNA that assembles peptides from mRNA chain

Question 5

What effect would a mutation have on the promoter?

Answer 5

Different expression pattern

Question 6

What effect would a mutation have on the non-coding region?

Answer 6

It would be a silent mutation since the introns get spliced out

Question 7

What are the types of mutations?

Answer 7

Non-sense, Missense, Frameshift and Silent

Question 8

What is a non-sense mutations effect?

Answer 8

Premature stop codon

Question 9

What is a missense mutations effect?

Answer 9

Change to the amino acid sequence

Question 10

What is a framshift mutations effect?

Answer 10

Insertion or deletion, can lead to entire peptide changes

Question 11

What is a silent mutations effect?

Answer 11

No change to the protein sequence

Question 12

What are the ideal parameters for PCR primer?

Answer 12

• Length 18-24 bp
• 40-60% G+C content
• Melting temp (Tm) 50-60 C
• Primers should have a Tm w/in 5 degrees of each other

Question 13

What is a recombinant DNA?

Answer 13

• A DNA molec. generated in the lab that brings together pieces of DNA from multiple sources
• Usually contain 2 pieces of DNA –> an engineered plasmid (vector) + gene of interest
• Can be inserted into organisms to carry out specific functions

Question 14

What is the plasmid?

Answer 14

• (aka a vector) are engineered DNA molecs which have defined features for a specific function (protein expression, clonning, ect.)

Question 15

What components do plasmid contain?

Answer 15

• Promoter sequence (to express inserted gene)
• Origin of replication (to amplify plasmid
• Selectable marker (to select transformed bacteria)
• Multiple cloning sites (MCS)(used to insert gene of interest)

Question 16

What are restriction enzymes?

Answer 16

• Endonucleases that cleave phosphodiester bonds b/w nucleotides @ sepcific DNA sequences (often palendromic)

Question 17

Explain cloning by restriction enzymes

Answer 17

• Cleaving both vector + insert w/ one restriction site has no orientation
• Using 2 sites results in only one possible orientation
• Blunt cutters insert w/ no orientation

Question 18

Explain cloning by PCR

Answer 18

• First we amplify our gene of interest through PCR w/ primers that incorporate RE sites
• After PCR, DNA can be cut w/ RE + subcloned into a vector

Question 19

What does the proofreading in transc?

Answer 19

DNA polymerase III
Works in the 3 -5 prime direction

Question 20

What do DNA gyrase, helicase and DNA polym I do respectively?

Answer 20

• Prevent supercoilling
• Unwind
• Declave DNA

Question 21

Which has more replication origins, DNA or bact?

Answer 21

DNA
- bact has only one and humans have thousands

Question 22

During what phase of the cell cycle does DNA replicate?

Answer 22

During the S phase of the cell cycle

Question 23

How does DNA know when to start replicating?

Answer 23

The machinery for replication requires specific proteins and those proteins are made during M and G1 phase

Question 24

What is the start codon?

Answer 24

AUG

Question 25

What does telomerase do?

Answer 25

Carries short RNA molecs complementary to 3 prime overhang

Question 26

Why are caps important?

Answer 26

- "protect" the telomere at the end of a chromosome

Question 27

Which is more stable RNA or DNA?

Answer 27

- RNA is more reactive because of the "OH" group - "OH" is more reactive than "H"

Question 28

Which is more stable Uracil or Thymine?

Answer 28

- Thymine because Uracil lacks a methyl group

Question 29

List all the reasons RNA is less stable

Answer 29

- Single stranded - Uracil instead of thymine - Has an OH instead of an H group

Question 30

What is the role of mRNA's?

Answer 30

Intermediary that passes information from DNA to protein

Question 31

What is the role of functional RNA

Answer 31

They don't incode info to make protein. Instead the RNA itself is the final functional product

Question 32

What tells the proteins where to go in the promoter?

Answer 32

Sigma factors

Question 33

What is sigma 70?

Answer 33

Housekeeping transc factor, binds to promoter of genes that are always on in the cell. Euk have no sigma factors

Question 34

What are the only aa that have hydroxyl group?

Answer 34

Tyrosine, serine and threonine

Question 35

What are the internal proteins and why are they internal?

Answer 35

Nonpolar proteins (b/c they are hydrophobic)

Question 36

What are the externall proteins and why are they internal?

Answer 36

Polar/Uncharged (hydrophillic) Polar/ post charged (binf DNA b/c DNA has net neg charge) Polar Charged (reactive + can form w/ other nearby aa)

Question 37

What deternines how the protein will fold?

Answer 37

The R group

Question 38

What does determiens the role of the protein?

Answer 38

Its structure

Question 39

Are codons overlapping?

Answer 39

No they are no overlapping; each nucleotide is part of only one codon

Question 40

Is the codon continuous?

Answer 40

Yes it is continuous; its read from a fix starting point and continues uniterrupted to the end of the open reading frame

Question 41

How many letters make up a codon?

Answer 41

3

Question 42

What is the equation to determine the number pf combinations for a codon?

Answer 42

4^n n= the number of codons

Question 43

What are the stop codons?

Answer 43

UAA, UAG, UGA