1. Unit 7: DNA Structure and Function

2. 7.1 DNA Structure and Function
KEY CONCEPTS
VOCABULARY
Who helped discover DNA?
What does DNA do for us?
What is the structure of DNA & what is DNA made of?
DNA
Adenine
Guanine
Cytosine
Thymine
Purines
Pyrimidines
Nucleotide

3. DNA DNA stands for _______________________________________
Large molecule that contains all genetic information
Functions of DNA:
Directs the activities of cells
Contains the instructions cells use to make:
What kinds of things do living organisms use proteins for?

4. History Rosalind Franklin took the
The x-ray pictures helped scientists to determine the shape of DNA.
What is the shape of a DNA molecule?

5. History James ____________ and Francis Crick built the first DNA model
They are given credit for first determining the double helix shape

6. Structure A strand of DNA is made of monomers called
Each nucleotide has three parts:
The nitrogen base always binds to the sugar of a nucleotide

7. Structure There are four different DNA nitrogen bases:
Adenine
Guanine
Cytosine
Thymine
Adenine and guanine are single-ringed purines
Cytosine and thymine are double-ringed pyrimidines

8. Structure
Label the following parts of the DNA nucleotides below: adenine, thymine, guanine, cytosine, purines, pyrimidines, phosphate, and sugar

9. Structure
Nucleotides bond together to form a double stranded DNA molecule
DNA’s structure looks like a twisted ladder
This structure is called the double helix
The deoxyribose and phosphate form the
Nitrogen bases bond together to form the

10. Structure

11. Structure
Label the following parts of the DNA molecule below: nucleotide, hydrogen bonds, sugar-phosphate backbone
Nucleotide
Sugar-phosphate backbone
Key
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)

12. Chargaff’s Base Pairing Rules
Adenine always bonds to thymine
Cytosine always bonds to guanine
The nitrogen bases are bonded
Why do only certain nitrogen bases bind to each other?

13. Chargaff’s Base Pairing Rules
Complete the other half of the DNA molecule below using Chargaff’s base pairing rules:
A T G A A C G T C A C C G T A C A T C G T

14. DNA and Chromosomes
In eukaryotic cells, DNA molecules are tightly wound into chromosomes
Where are chromosomes located in eukaryotic cells?
Chromosomes contain all the DNA…

15. Label the following parts of the diagram below: GENE, CELL, NUCLEUS, CHROMOSOME, DNA
_______________
_______________
_______________
_______________
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