DNA Structure & Replication PPT

Question 1

chemical compound that passes hereditary information from generation to generation

Answer 1

deoxyribonucleic acid (DNA)

Question 2

What are the building blocks of DNA?

Answer 2

DNA is composed of a long chain of nucleotides.

Question 3

Each nucleotide in DNA has ___ components and are attached with ___ bonds.

Answer 3

3,

covalent

Question 4

How many different nucleotides make up DNA?

Answer 4

4

Question 5

2 ring nitrogen base structure

Answer 5

purines

Question 6

1 ring nitrogen base structure

Answer 6

pyrimidines

Question 7

Which nucleotides have a purine base?

Answer 7

adenine,

guanine

Question 8

Which nucleotides have a pyrimidine base?

Answer 8

thymine,

cytosine

Question 9

Who discovered how the nucleotides are assembled and when?

Answer 9

Erwin Chargaff (1949)

Question 10

How are the nucleotides assembled?

Answer 10

purines attach to pyrimidines (A=T and G=C)

Question 11

Whose x-ray diffraction images suggested DNA structure?

Answer 11

Rosalind Franklin

Question 12

Describe DNA structure.

Answer 12

• long and thin
• uniform diameter
• two varying repeats suggests a double coil/helix

Question 13

determined the double helix structure of DNA and built a model to display it; won a Nobel prize

Answer 13

Watson and Crick (1953)

Question 14

a twisted ladder structure; sugar-phosphate are the sides that make up a “backbone”; nitrogen bases attach across as the rungs (A=T and G=C); two strands run antiparallel and are complimentary to each other (3 prime to 5 prime)

Answer 14

double helix structure

Question 15

Nitrogen bases in DNA attach with ___ bonds.

Answer 15

hydrogen

Question 16

flow of information from DNA to RNA to protein

Answer 16

central dogma of molecular biology

Question 17

process of creating a new DNA molecule

Answer 17

replication

Question 18

process of creating RNA from DNA

Answer 18

transcription

Question 19

process of creating proteins from RNA

Answer 19

translation

Question 20

DNA replication must occur ___ cell division.

Answer 20

before

Question 21

Cell must duplicate its genome before it ___.

Answer 21

divides

Question 22

Each strand acts as a ___ to create a new strand.

Answer 22

template

Question 23

Describe the origins of replication.

Answer 23

1. Helicase enzyme unwinds DNA in both directions
2. forms a replication bubble and binding proteins stabilize each strand
3. at each end of the replication bubble is a replication fork

Question 24

enzyme which adds only to an existing strand laid by a RNA primase enzyme; gets energy by breaking off two phosphates

Answer 24

DNA polymerase

Question 25

What’s the problem with using DNA polymerase to add in free nucleotides?

Answer 25

only adds nucleotides to the 3 prime (3’) end

Question 26

One strand is made continuously (5’-3’) while the other strand is made in sections called ___ and gaps are sealed in by ___.

Answer 26

Okazaki fragments,

DNA ligase

Question 27

the end result is 2 identical DNA molecules formed from the original; during cell division one complete copy is given to the new cell while one is retained in the original cell; each new molecule consists of one old strand and one new strand

Answer 27

semi-conservative replication

Question 28

Are mistakes possible in DNA replication?

Answer 28

yes

Question 29

What enzymes can extract mistakes and repair DNA?

Answer 29

DNA polymerase,

DNA ligase

Question 30

If an error in DNA replication persists, a ___ results.

Answer 30

mutation

Question 31

DNA is contained in the nucleus as ___, but condenses into ___.

Answer 31

chromatin,

chromosomes

Question 32

discreet packages of DNA

Answer 32

chromosomes

Question 33

a sequence of DNA nucleotides that codes for a specific protein or RNA molecule

Answer 33

gene

Question 34

all the genetic material in a cell

Answer 34

genome