The document describes the structure of DNA. DNA consists of two strands coiled around each other in a double helix shape. Each strand is composed of nucleotides, which contain a phosphate group, 5-carbon sugar (deoxyribose), and a nitrogenous base. The bases on each strand bond with their complementary bases on the other strand through hydrogen bonds, with cytosine bonding to guanine via three hydrogen bonds and thymine bonding to adenine via two hydrogen bonds. This hydrogen bonding contributes to the specificity of base pairing in DNA.

1. The Human
Body Recipe
DNA:

2. • DeoxyriboNucliec Acid •
01

4. In chromosomes, DNA is
tightly wound around
Histone proteins and
compactedly coiled and
present in the cell nucleus.
DNA consists of two strands
that are coiled around one
another, forming a double
helix shape (B-form DNA).

5. ● Each strand of DNA is a polynucleotide
chain that is composed of multiple
nucleotides.
● Nucleotides consist of 3 main parts:
○ A phosphate group
○ A 5-carbon sugar (deoxyribose)
○ A nitrogenous base
• DNA structure

6. Although Nucleotides come together (join) through
covalent bonds in the backbone, the two strands of DNA
interact through non-covalent hydrogen bonds between the
bases.
Each base forms multiple hydrogen bonds with its
complementary base on the opposite strand.
Base pair

7. How can these non-covalent hydrgen bonds help us?
This hydrogen bonding contributes to the specificity of base pairing.
Cytosine pairs with guanine
through three hydrogen bonds
Thymine pairs with adenine
through two hydrogen bonds

8. Have double rings
(guanine and adenine)
pyrimidines purines
Characterized by their
single structure
(thymine and cytosine)
-The geometry of the AT or TA and GC or CG bases pairs is the same.
-Each turn of the helix measures approximately ten base pairs.
-stacking of the bases stabilizes the double helix structure.
NOTES:

9. Adenine
Cytosine
Guanine
Thyamine
3 hydrogen bonds
2 hydrogen bonds
Purines
Pyrimidines

10. Pi-Pi interactions:
they form in the aromatic rings of the bases
stack next to eacth other and share electron
probabilities.
Major and minor grooves:
Two repeating and alternating spaces formed by
the regularity of helical shape.
Major grooves: contains base
pair specific information
Minor grooves: contains base
pair non-specific information

11. It’s the time for questions! :
Q. What two parts of a nucleotide do not change throughout the structure of DNA?
answer choices
Five-Carbon Sugar and Nitrogen Base
Phosphate Group and Nitrogen Base
Five-Carbon Sugar and Phosphate Group
All components remain the same throughout the DNA structure
Q. Nitrogenous bases are joined by which type of bond?
answer choices
polar bonds
ionic bonds
covalent bonds
hydrogen bonds

12. Q. Which shows the correct complementary base pairing for
DNA?
answer choices
C-A, T-G
A-G, C-T
C-G, U-A
T-A, G-C
Q. Which of the following units are repeatedly joined together to
form a strand of DNA?
answer choices
amino acids
nucleotides
fatty acids
polysaccharides

13. Q.A five-carbon sugar found in DNA.
answer choices
ribose
guanine
deoxyribose
Helicase
Q. Pyrimidines are:
Thymine and cytosine
Thymine and adenine
Adenine and guanine
Guanine and cytosine