Composition and Structure of DNA

Question 1

Nucleic acid

Answer 1

acidic substance made up of C,H,O,N,P

Question 2

What are the 2 types of nucleic acid?

Answer 2

DNA, RNA

Question 3

What does DNA stand for and where is it found?

Answer 3

Deoxyribonucleic acid, found in nucleus

Question 4

What does RNA stand for and where is it found?

Answer 4

Ribonucleic acid, cytoplasm

Question 5

What is DNA made up of?

Answer 5

Repeating units called nucleotides

Question 6

What does each nucleotide in DNA have?

Answer 6

5-carbon sugar called deoxyribose, phosphate group, nitrogenous base

Question 7

What are the kinds of nitrogenous bases? How many are there?

Answer 7

Four kinds, adenine, cytosine, guanine, and thymine.

Question 8

What is a Purine nitrogenous base?

Answer 8

A double ringed one.

Question 9

What are the Purine nitrogenous bases? How many are there?

Answer 9

2, Adenine and Guanine.

Question 10

What is a Pyrimidine nitrogenous base?

Answer 10

A single ringed one.

Question 11

What are the Pyrimidine nitrogenous bases? How many are there?

Answer 11

2, Cytosine and Thymine.

Question 12

In the nitrogenous bases, what bonds to what?

Answer 12

Each Purine bonds to a Pyrimidine. Adenine and Thymine, and Guanine and Cytosine.

Question 13

Who were James Watson and Francis Crick?

Answer 13

Scientists who worked for someone else. Using X-Ray photos of DNA, they formed a model of the structure of DNA.

Question 14

What year were Watson and Crick?

Answer 14

1953

Question 15

Who took the pictures Watson and Crick used?

Answer 15

Rosalind Franklin.

Question 16

What did Watson and Crick determine?

Answer 16

DNA was in the shape of a double helix, phosphate and sugar formed the sides, nitrogenous bases the rungs, base pair bonds, complimentary.

Question 17

Double helix

Answer 17

Twisted ladder

Question 18

Why are the two strands of the double helix DNA complimentary?

Answer 18

Bc of the nitrogenous base pairings and bonds. If one was AGGTTAC, the other would read TCCAATG

Question 19

What is DNA replication?

Answer 19

Process of making a copy of DNA

Question 20

Template

Answer 20

pattern on which each new strand is built

Question 21

Why does each strand serve as a template?

Answer 21

In order to replicate itself, since each strand is complimentary.

Question 22

replication forks

Answer 22

areas where double helix separates (called this bc of their y shape)

Question 23

What is the first step of replication?

Answer 23

The double helix unwinds, and bases on one strand separate from the bases on the other.

Question 24

DNA polymerase

Answer 24

enzyme that attaches to each strand of the separated DNA during second step of DNA replication

Question 25

What does the DNA polymerase do?

Answer 25

moves along the strand, reads each base, attaching new complimentary bases according to the base pair rule

Question 26

When does replication stop?

Answer 26

When all of the DNA has been copied and the polymerases are signaled to detach, one per strand

Question 27

Conclusion of replication

Answer 27

2 DNA molecules are formed, each composed of a new strand and original strand (called semi conservative replication)

Question 28

In conclusion of replication, what do the sequences of bases in these two strands look like?

Answer 28

Identical to each other and the original DNA molecule

Question 29

What may happen during replication?

Answer 29

errors may occur and the wrong bases may be added

Question 30

What ability does DNA polymerase have that can prevent errors?

Answer 30

Proofread the new DNA strand, backtrack and removing the incorrect nucleotide, replace it w/ the correct one

Question 31

How many errors occur per nucleotides due to DNA polymerase?

Answer 31

1 error:1 billion nucleotides