U3

Question 1

What are the 3 components of nucleotides?

Answer 1

1. phosphoric acid (phosphate group)
2. 5 carbon sugar (deoxyribose)
3. 1 of 4 nitrogenous bases

Question 2

What is the double strand of the double helix held in place by?

Answer 2

hydrogen bonds

Question 3

What are the 3 functions of DNA?

Answer 3

1. replicates itself 2. controls the activity of the cell 3. mutations for variety in living things

Question 4

Explain the key components in the 4 steps of DNA replication

Answer 4

1. An enzyme untwists the strands, helicase breaks the weak hydrogen bonds between base pairs to unzip DNA
2. DNA polymerase helps present nucleotides complementary base pair
3. ligase glues the alternating sugar phosphate backbone together
4. Two identical DNA molecules wind back up into a helix

Question 5

*look at page 22