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DNA
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5a. Know the general structures and functions of DNA, RNA & protein.
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DNA Nucleic Acids Function: genetic material ____________________
genes blueprint for new cells blueprint for next generation blueprint for building proteins ______________________ DNA proteins
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DNA Nucleotide O O=P-O N CH2 O C1 C4 C3 C2 5
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Double strand twists into a double helix
DNA Double strand twists into a double helix ______________ between nitrogen bases join the 2 strands ______________ A :: T C :: G the two strands can separate when our cells need to make copies of it It’s a helix or B sheet within a single region. Can have both in one protein but a specific region is one or another
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DNA - double helix T A P O 1 2 3 4 5 P O 1 2 3 4 5 G C T A
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Frederick Griffith British bacteriologist 1928 = performed experiment on __________________________ _____________________________. 2 strains of the bacteria Type S = ____________________ Type R = ____________________
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Griffith’s Rats First he injected ___________________ bacteria into rats:
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Second he injected ____________________ into the rats.
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Next he injected ________________________ bacteria
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Finally he injected a _______________________________________ :
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Results of experiments:
Because the dead rat tissue showed ________________________, something “brought the Type S back to life” Actually ________________________________________________ _____________________________________________ Known as ___________________________. Confirmed by Avery, MacLeod, and McCarty in 1944 Oswald Avery Canadian biologist ( ) Discovered “________________________” in 1944 with a team of scientists.
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Hershey and Chase 1952 Solve the debate on whether DNA or proteins are genetic material. They used ___________ ______________________ to prove that _________ ______________________.
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Phoebus A. Levene 1920’s discovered _________________ (building blocks of DNA) ____________
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The Components of DNA There are 4 kinds of bases in in DNA: _________
DNA is made up of nucleotides. Each nucleotide has three parts: a deoxyribose molecule, a phosphate group, and a nitrogenous base. There are four different bases in DNA: adenine, guanine, cytosine, and thymine.
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Chargaff’s rules The amounts of _____________________________________ in DNA The amounts of ____________________________________________. Named after Erwin Chargaff
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Hydrogen Bonds C N O The bases attract each other because of ________________________. (The bonds between _________________________ are shown here.)
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O C N Hydrogen Bonds, cont.
When making ___________ ____________, cytosine always pairs up with guanine, and adenine always pairs up with thymine. (_________________________ are shown here.)
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History ______________________________ & Maurice Wilkins had taken the 1st pictures of DNA using __________________________
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Structure of DNA Discovered in 1953 by two scientists: ____________________ (USA) ____________________ (GBR) Known as the ____________ __________________________.
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Watson Crick Wilkins has become a historical footnote and ___________________ are remembered as the Fathers of DNA
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phosphate deoxyribose bases One Strand of DNA
The backbone of the molecule is alternating ____________________and _________________, a sugar, parts. The teeth are _________________________. phosphate deoxyribose {Point to the 3-D mode, if you have one, to show the parts as you discuss them.} bases
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The double-helix A twisted ladder with two long chains of alternating ___________________________. The ________________________ act as the “rungs” joining the two strands.
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The __________________________________
History The __________________________________ Francis Harry Compton Crick James Dewey Watson Rosalind Franklin (Died of cancer 1958) Maurice Hugh Frederick Wilkins
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Making New Cells __________________
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DNA cell nucleus Copying DNA A dividing cell _________________________
creates 2 copies of all DNA separates the 2 copies to opposite ends of the cell splits into _________________________ Since the DNA starts _____________________ in the nucleus, if you tried to divide it like that, it could __________________ DNA cell nucleus
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2 strands of DNA helix are ________________________
Copying DNA ___________________ 2 strands of DNA helix are ________________________ have one, can build other have one, can rebuild the whole when cells divide, they must duplicate DNA exactly for the new “daughter” cells Why is this a good system?
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_________________________
Chromosomes & DNA _________________________
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Organizing & packaging DNA
cell nucleus DNA has been “____________” _____________________ cell nucleus 4 chromosomes in this organism _____________________
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All organisms have two types of chromosomes:
Genetic facts All organisms have two types of chromosomes: __________________ Both female and male have identical chromosomes except for one pair. ______________ are located on chromosomes
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Chromosomes of Human Male
23 pairs
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Chromosomes of Human Female
23 pairs
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Usually the Y chromosome. __________________ Male genotype = XY
Male vs. Female MALE Usually the Y chromosome. __________________ Male genotype = XY FEMALE Usually the X chromosome. Larger than the Y __________________________ Except Birds Male = XX Female = XY
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Paired bases DNA structure double helix 2 sides like a ladder Bases match together A pairs with T A = T C pairs with G C = G
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DNA replication Before DNA can be replicated, it must be _______________ __________________ (enzyme that opens up strands) - break the ____________________ between bases DNA Helicase
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Enzyme _______________ DNA bases in nucleus DNA replication DNA
polymerase
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Completing the replication
After the DNA molecule splits apart, _____________________ bond to their complimentary nitrogen bases by _____________________.
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Get 2 ____________________________ to split between new cells
New copies of DNA Get 2 ____________________________ to split between new cells DNA polymerase DNA polymerase
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Copying DNA ______________________ allows DNA to be easily copied _______________________ means that you conserve part of the original structure in the new one. You end up with _______________________.
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Copied & Paired Up Chromosomes
_____________________ human chromosomes ready for mitosis ___________
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DNA must be duplicated…
chromosomes in cell 4 single-stranded chromosomes nucleus cell _______________________ nucleus cell ______________________ duplicated chromosomes 4 double-stranded chromosomes
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Mitosis: Dividing DNA & cells
Stage 1: _______________________ Copy DNA! DNA cell nucleus (_________________)
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Mitosis: Dividing DNA & cells
Stage 2: ________________________________ DNA is wound up into chromosomes to keep it ____________ duplicated chromosomes Wind up! cell nucleus (______________)
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Mitosis: Dividing DNA & cells
Stage 3: Chromosomes line up _________________________________ attached to protein “cables” that will help them move Line up! duplicated chromosomes lined up in middle of cell (_____________)
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Mitosis: Dividing DNA & cells
Stage 4: Chromosomes separate ________________________________ start moving to opposite ends Separate! chromosomes split & move to _____________ (___________)
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Mitosis: Dividing DNA & cells
Stage 5: Cell starts to divide cells start to divide _____________________ Divide! (______________)
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Mitosis: Dividing DNA & cells
Stage 6: ______________________ cells separate now they can do their every day jobs Bye Bye! (_____________)
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New “daughter” cells Get 2 exact copies of original cells ______________
