12.1 DNA: STRUCTURE & FUNCTION DNA—deoxyribonucleic acid
12.1 DNA: STRUCTURE & FUNCTION
DNA—deoxyribonucleic acid
BACKGROUND INFO--NUCLEUS
-NUCLEUS is control center of the cell—-NUCLEUS controls all cell activities
including:cell reproduction & hereditystorage of genetic information
NUCLEOTIDES DNA GENES CHROMOSOME S NUCLEUS CELLS
BACKGROUND INFO--PROTEINS
PROTEINS-building blocks for every structure in your body-control chemical processes in the cell
DNA FUNCTION
DNAStorage/Transmit genetic information
DNA’s primary function – make PROTEINS
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
DNA STRUCTURE
1953—James Watson & Francis Crick discovered-double helix = twisted staircase-unwound resembles a ladder
DNA STRUCTURE
CRICK LETTER SOLD FOR MILLIONS
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DNA Double Helix
NitrogenousNitrogenousBase (A,T,G or C)Base (A,T,G or C)
““Rungs of ladder”Rungs of ladder”
““Legs of ladder”Legs of ladder”
Phosphate &Phosphate &Sugar BackboneSugar Backbone
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NUCLEOTIDES-repeating sub-units of DNA1 nucleotide = 1 sugar, 1 phosphate, 1 base
• 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
NUCLEOTIDE INFO:
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
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
DNA STRUCTURE
*CHARGAFF’S RULE
THYMINE = ADENINE
GUANINE = CYTOSINE
CREATE: memory device for pairing nitrogenous
bases
T A G C
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)
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DNA STRUCTURE
P
P
P
O
O
O
1
23
4
5
5
3
3
5
P
P
PO
O
O
1
2 3
4
5
5
3
5
3
G C
T A
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THINK – PAIR – SHARE
-What are the repeating units in DNA called?
Nucleotides-What 3 things make up a DNA nucleotide?
SugarPhosphateNitrogen containing base
NITROGENOUS BASE PAIR RULES
A T G A A G T T T T T GG C T G G C T A G
CREATE a matching (complementary) DNA sequence for the following strand:
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
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
MODEL structures of DNA by labeling & coloring
ADENINE--yellow
THYMINE--blue
GUANINE--orange
CYTOSINE--grey
SUGAR--pink
PHOSPHATE--green
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NUCLEOTIDE
O=P-O O
PhosphatePhosphate GroupGroup
NNitrogenous baseNitrogenous base (A, G, C, or T)(A, G, C, or T)
CH2
O
C1C4
C3 C2
5
SugarSugar(deoxyribose)(deoxyribose)
O
copyright cmassengale
APPLY: COMPLETE the DNA CONCEPT MAP
twisted ladder
DNA
double helix
Watson & Crick
1953
nucleotides
deoxyribose
phosphate group
nitrogenous base
adenine thymine
cytosine
guanine
-store/transfer genetic info-produce proteins
12.1 DNA LABELING
phosphate group
G=guanine
deoxyribose sugar
A=adenine
12.1 DNA LABELING
G T GA G C
12.1 DNA LABELING
cell
chromosome
nucleus
base pairs
histones – nucleosomes
DNA
DNA EXTRACTION LAB
1-READ BACKGROUND INFO-HIGHLIGHT important info-ANSWER Qs- MRS. S
2-LAB-FOLLOW PROCEDURE-CLEAN-UP
3-LAB Qs-DISCUSS/ANSWER- MRS. S
4-COMPLETE APPLICATION NOTES w/lab partners
DNA EXTRACTION LAB
DNA EXTRACTION LAB
PRE-LAB:1-How much flax seed? _________2-Water temp? _________3-Lysis solution? __________4-Bubbles/foam? __________5-Purpose of tilting beaker? ___________6-Let beaker stand? ___________7-Identify DNA? _____________
1 tsp
HOT
5 drops
remove w/paper towel
keep layers from separating2+
minuteswhite/stringy—looks like snot!
DNA EXTRACTION LAB
ANALYSIS:1- Purpose of lysis? _________2- DNA code of life? _________3- DNA made of? __________
4- 10% of cell? __________5- Add alcohol? ___________8- 2 VARIABLES:
free DNA
-lysis solution—type/amount-source of DNA-temp of water –OR- alcohol-
-carries info for living things-nucleotides:
P-group/sugar/nitrogen bases-C / H / O / P / N
-tightly wound so compact
DNA less soluble in alcohol
12.1 VOC
DNA MODEL
1-ATTACH KEY CHAIN2-WRITE BASE PAIRS ON WHITE BEADS
-BOTH SIDES3-CHECK KEYCHAIN with MRS. P4-TWIST5-ANSWER ANALYSIS QUESTIONS----------------check obj / vocab with table partner---------------6- GRADE ANALYSIS Q
ANALYSIS 1- What base does ADENINE pair with?-THYMINE
2- What base does guanine pair with?-CYTOSINE
3-_______________’s rule says C=G and A=T4- What is the scientific name of the shape of the DNA molecule?-double helix5- What are the 3 components of a nucleotide?-phosphate -sugar -nitrogen base6- What are the 2 parts of the nucleotide that make up the SIDES of the ladder?
- Phosphate -sugar
CHARGAFF
DNA MODEL
ANALYSIS 7- What is the name of the sugar molecule in DNA?-deoxyribose8- What type of bond holds the 2 bases together?-hydrogen9-What is the FUNCTION of DNA?-10- The sides of the DNA ladder run “anti-parallel”.
What does this mean?-OPPOSITE
11/12- A-G-C-T-C-A-G-T-T-A-G-C-G-G-C-A-T-T-CT-C-G-A-G-T-C-A-A-T-C-G-C-C-G-T-A-A-G
DNA MODEL