Gizmo Key Terms: Building DNA
double helix
the shape of a DNA molecule (twisted ladder)
DNA
- incredible molecule that forms the basis of life on Earth
- DNA molecules contain instructions for building every living organism on Earth (from
tiniest bacterium to a massive blue whale)
- has the ability to replicate (make copies of) itself, allowing things to grow and
reproduce
How do you think a DNA molecule makes a copy of itself?
by breaking the weak hydrogen bonds that link the paired bases
What are the two DNA components shown in the Gizmo?
phosphates and nucleosides
Nucleoside
has two parts:
- pentagonal sugar (deoxyribose) and a nitrogenous base.
When a nucleoside is joined to a phosphate, it is called a __________.
nucleotide
How many different nitrogenous bases are there?
4
Names of the nitrogenous bases:
- adenine
- cytosine
- guanine
- thymine
Adenine (A) joins to _______.
thymine (T)
Cytosine (C) joins to _______.
guanine (G)
Thymine (T) joins to _______.
adenine (A)
What makes up the sides of the DNA molecule?
phosphates and sugar (deoxyribose)
What makes up the "rungs" of the DNA molecule?
nitrogenous bases
An enzyme is a protein that facilitates certain cell processes. What does this enzyme
(helicase) do to the DNA molecule?
it splits it in half (helicase slices open hydrogen bonds between the base pairs)
What are the three parts of a nucleotide?
phosphate, sugar (deoxyribose), nitrogenous base
Drag one of the nucleotides to a corresponding nitrogenous base on one of the two
strands. What is the role of DNA polymerase in this process?
DNA moves the nitrogenous bases, helping them to connect with the right molecule.
double helix
the shape of a DNA molecule (twisted ladder)
DNA
- incredible molecule that forms the basis of life on Earth
- DNA molecules contain instructions for building every living organism on Earth (from
tiniest bacterium to a massive blue whale)
- has the ability to replicate (make copies of) itself, allowing things to grow and
reproduce
How do you think a DNA molecule makes a copy of itself?
by breaking the weak hydrogen bonds that link the paired bases
What are the two DNA components shown in the Gizmo?
phosphates and nucleosides
Nucleoside
has two parts:
- pentagonal sugar (deoxyribose) and a nitrogenous base.
When a nucleoside is joined to a phosphate, it is called a __________.
nucleotide
How many different nitrogenous bases are there?
4
Names of the nitrogenous bases:
- adenine
- cytosine
- guanine
- thymine
Adenine (A) joins to _______.
thymine (T)
Cytosine (C) joins to _______.
guanine (G)
Thymine (T) joins to _______.
adenine (A)
What makes up the sides of the DNA molecule?
phosphates and sugar (deoxyribose)
What makes up the "rungs" of the DNA molecule?
nitrogenous bases
An enzyme is a protein that facilitates certain cell processes. What does this enzyme
(helicase) do to the DNA molecule?
it splits it in half (helicase slices open hydrogen bonds between the base pairs)
What are the three parts of a nucleotide?
phosphate, sugar (deoxyribose), nitrogenous base
Drag one of the nucleotides to a corresponding nitrogenous base on one of the two
strands. What is the role of DNA polymerase in this process?
DNA moves the nitrogenous bases, helping them to connect with the right molecule.
