Intro to DNA

Question 1

What are the four types of nitrogenous bases? How do they pair together?

Answer 1

Adenine—>Thymine.

Cytosine—> Guanine.

Question 2

What are the three structures that make up a DNA strand?

Answer 2

A nitrogenous base, deoxyribose sugar, and a phosphate group.

Question 3

What type of bond connects the nitrogenous bases together?

Answer 3

A hydrogen bond.

Question 4

What type of bond connects the detoxified and the phosphate group together?

Answer 4

A covalent bond.

Question 5

How many hydrogen bonds connect adenine and thymine together?

Answer 5

2 hydrogen bonds.

Question 6

How many hydrogen bonds connect guanine and cytosine together.

Answer 6

3 hydrogen bonds.

Question 7

What does 5’ connect to and what does 3’ connect to?

Answer 7

5’ connects the 5th carbon atom to the phosphate group, and the 3’ connects the 3rd carbon atom to the hydroxyl group.

Question 8

DNA molecules run ____ from one another.

Answer 8

antiparallel.

Question 9

How many chromosomes does each human have per cell?

Answer 9

46 chromosomes, 23 pairs.

Question 10

What role do chromosomes play in DNA?

Answer 10

Chromosomes condense your DNA to split your cell into two.

Question 11

What is mitosis?

Answer 11

A replication when one cell duplicates into two cells.

Question 12

What connects the deoxyribose sugars together?

Answer 12

A phosphate group

Question 13

What makes N15 different from N14?

Answer 13

N15 has an extra proton and is heavier compared to N14.

Question 14

Where do N15 and N14 come from?

Answer 14

Comes from E. coli bacteria.

Question 15

What happens to the DNA when it makes a copy of itself.

Answer 15

When the heavy DNA makes a copy of itself, it gets lighter.

Question 16

What are the three methods of DNA replication? Which method is correct?

Answer 16

The three methods are semi-conservative, conservative, and dispersive. Semi-conservative is correct.

Question 17

What are the three steps to the semi-conservative process?

Answer 17

1. Start with a parent molecule.
2. Two complementary strands serve as templates.
3. Two DNA molecules, one “old” strand, one “new” strand. Both are identical to the parent molecule.

Question 18

How long does DNA replication take?

Answer 18

Can replicate in just a few hours.

Question 19

How does the leading strand copy?

Answer 19

The leading strand copies continuously towards the replication fork 5’ to 3’.

Question 20

How does the lagging parent template copy?

Answer 20

The lagging parent template runs 5’ to 3’ towards the replication fork.

Question 21

What is the first step of the DNA replication process?

Answer 21

The enzyme Helicase breaks H bonds between the Nitrogenous bases.
New strands are extended at the replication fork in both directions.

Question 22

What is the second step of the DNA replication process?

Answer 22

Primase works to identify the location of the gene where DNA polymerase is to replicate.
DNA Polymerase helps to attach the new nucleotides as they align with their base pair in the 5’ to 3’ direction.

Question 23

What is the third step of the DNA replication process?

Answer 23

Lagging strands (Okazaki fragments) extend in pieces away from the replication fork.
The enzyme, DNA ligase attaches the fragments on the lagging strand into one piece.

Question 24

What are histones?

Answer 24

Protein molecules whose DNA is tightly coiled.

Question 25

What are the four enzymes used for DNA replication?

Answer 25

Primase, Ligase, DNA polymerase, and helicase.