PCR and 16S Gene

Question 1

What is the primary structure of DNA?

Answer 1

backbone and nitrogen-containing bases

Question 2

What is the backbone made of?

Answer 2

sugar and phosphate groups of deoxyribonucleotides (bases)

Question 3

Where do nitrogen-containing bases project from?

Answer 3

from back of backbone

Question 4

Does DNA have directionality?

Answer 4

yes

Question 5

What are the 2 ends of DNA named?

Answer 5

3’ and 5’

Question 6

What are the characteristics of the 3’ end?

Answer 6

has exposed group on 3’ carbon deoxyribose

Question 7

What are the characteristics of the 5’ end?

Answer 7

5’ carbon phosphate group

Question 8

What does DNA synthesis occur after?

Answer 8

creation of a phosphodiester bond

Question 9

What is polymerase chain reaction (PCR)?

Answer 9

technique used to amplify specific regions of DNA for sequencing and genetic analysis

Question 10

What are the 3 steps of PCR?

Answer 10

Denaturation
annealing
elongation

Question 11

What temperature is denaturation?

Answer 11

95 degrees celsius

Question 12

What temperature is annealing?

Answer 12

68 degrees celsius

Question 13

What temperature is elongation?

Answer 13

72 degrees celsius

Question 14

Where do ribosomes coordinate protein synthesis?

Answer 14

from an RNA template

Question 15

What are the 2 ribosome subunits?

Answer 15

prokaryotes and eukaryotes

Question 16

What do prokaryotes have?

Answer 16

23S, 5S, 16S

Question 17

What do eukaryotes have?

Answer 17

28S, 5.8S, 5S, 18S

Question 18

Why do we use 16S sequence?

Answer 18

to identify microbes

Question 19

What are chromosomes?

Answer 19

large pieces of DNA with many genes

Question 20

What is denaturation?

Answer 20

heat briefly to separate DNA strands

Question 21

What is annealing?

Answer 21

cool to allow primers to bond hydrogen bond with ends of target sequence

Question 22

What is elongation?

Answer 22

DNA polymerase adds nucleotides to 3’ end of each primer

Question 23

What is the importance of the primers in a PCR reaction?

Answer 23

they act as the starting point for DNA synthesis
defines the region that will be amplified

Question 24

What is a primer?

Answer 24

short fragment of single-stranded DNA that binds to one strand of DNA template and is recognized by DNA polymerase as the starting point to copy DNA

Question 25

What is agarose gel electrophoresis?

Answer 25

separates DNA fragments based on charge (positive or negative), size in base pairs (bp), and conformation (linear vs circular)

Question 26

What charge is DNA?

Answer 26

partial negative on the phosphate group of the backbone

Question 27

Where do DNA molecules loaded in gel migrate?

Answer 27

towards positive electrode

Question 28

How fast to smaller molecules travel?

Answer 28

rapidly

Question 29

What speed to larger molecules travel?

Answer 29

they are slowed down as they bump into gel matrix

Question 30

What is PCR product?

Answer 30

contains millions of copies of one specific stretch of DNA

Question 31

What is a DNA template?

Answer 31

any DNA molecule such as bacterial chromosome, plasmid, and fragment of DNA