1. 12.1 DNA: STRUCTURE & FUNCTION
DNA—deoxyribonucleic acid

2. BACKGROUND INFO--NUCLEUS
-NUCLEUS is control center of the cell—
-NUCLEUS controls all cell activities including:
cell reproduction & heredity
storage of genetic information
DNAGENESCHROMOSOMESNUCLEUSCELLS

3. BACKGROUND INFO--PROTEINS
-building blocks for every structure in your body
-control chemical processes in the cell

4. DNA FUNCTION
DNAStorage/Transmit genetic information
DNA’s primary function –
code for PROTEINS

5. DNA BLUEPRINT of LIFE—
ALL body cells (except sex cells) have same copies of DNA to produce protein structures….
all 70 BILLION of them!!
DNA is found in other organelles—
mitochondria & chloroplasts

6. DNA STRUCTURE 1953—James Watson & Francis Crick discovered
-double helix = twisted staircase
-unwound resembles a ladder

7. DNA STRUCTURE

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DNA Double Helix
Nitrogenous
Base (A,T,G or C)
“Rungs of ladder”
“Legs of ladder”
Phosphate &
Sugar Backbone
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9. NUCLEOTIDES -repeating sub-units of DNA
1 nucleotide = 1 sugar, 1 phosphate, 1 base

10. NUCLEOTIDES stack on top of each other to form sides of DNA
NUCLEOTIDE INFO:
1 nucleotide :
1 sugar,
1 phosphate
1 base
NUCLEOTIDES stack on top of each other to form sides of DNA
1side of DNA upside down--“anti-parallel”
2 bases attached with hydrogen bonds

11. -A = Adenine -G = Guanine NITROGENOUS BASES
PURINES – 2 rings of C and N
-A = Adenine
-G = Guanine
*2 rings--each has 2 n’s
*both end in “nine”
Double ring has nine sides

12. T=Thymine C = Cytosine NITROGENOUS BASES
PYRIMIDINE – single ring of C and N
T=Thymine
C = Cytosine
*1 ring--each has 1 n*
*both have a “y” –
so does pyrimidine

13. DNA STRUCTURE *CHARGAFF’S RULE THYMINE = ADENINE GUANINE = CYTOSINE
CREATE: memory device for pairing nitrogenous bases T A G C

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DNA STRUCTURE P O 1 2 3 4 5 P O 1 2 3 4 5 G C T A
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15. ANTIPARALLEL SET 2 PENCILS PARALLEL TO EACH OTHER
--POINT 1ST PENCIL UP
--POINT 2ND PENCIL DOWN
 = ANTI-PARALLEL
One strand of DNA runs from 5’ to 3’ (sugars)
The other strand runs in opposite direction - 3’ to 5’ (sugars)

16. Nucleotides THINK – PAIR – SHARE
-What are the repeating units in DNA called?
Nucleotides
-What 3 things make up a DNA nucleotide?
Sugar
Phosphate
Nitrogen containing base

17. NITROGENOUS BASE PAIR RULES
CREATE a matching (complementary) DNA sequence for the following strand:
A T G A A G T T T T T GG C T G G C T A G

18. DNA: Blueprint of Life
-ANALYZE why DNA is called the “BLUEPRINT of LIFE”
-every cell in your body has the same copies of DNA
–pattern to produce protein structures

19. NUCLEUS: Control Center of the Cell
-INFER why the nucleus is called the “CONTROL CENTER” of the cell
-controls all activities of the cell including cellular reproduction and heredity

20. APPLY: COMPLETE the DNA CONCEPT MAP
nucleotides
twisted ladder
produce proteins
double helix
nitrogenous base
phosphate group
Watson & Crick
deoxyribose
guanine
adenine
thymine
cytosine
1953

21. MODEL structures of DNA by labeling & coloring
SUGAR--pink
PHOSPHATE--green
CYTOSINE--grey
GUANINE--orange
THYMINE--blue
ADENINE--yellow

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NUCLEOTIDE
O=P-O O
Phosphate
Group N
Nitrogenous base
(A, G, C, or T) O
CH2 O C1 C4 C3 C2 5
Sugar
(deoxyribose)
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