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

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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