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Biology I. Chapter 11—DNA: The Molecule of Heredity. Chapter 11 Section 1: DNA and Genes. Understanding the structure and role of DNA helps us make advances in the following research areas: ____________________ ____________________ ____________________ ____________________
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Biology I • Chapter 11—DNA: The Molecule of Heredity
Chapter 11 Section 1: DNA and Genes • Understanding the structure and role of DNA helps us make advances in the following research areas: • ____________________ • ____________________ • ____________________ • ____________________ • ____________________ • ____________________ genetic disorders viral diseases cancer aging genetic engineering criminal investigations Shetland ponies
11.1 Section Objectives – page 281 Section Objectives: Analyze the structure of DNA Determine how the structure of DNA enables it to reproduce itself accurately.
Section 1 Vocabulary • Nucleotide • Double helix • DNA replication
Section 11.1 Summary – pages 281 - 287 What is DNA? • A large __________________ containing genetic information that codes for the production of _______________ • Proteins make up many _______________ components of our bodies • Special proteins, called __________, are involved in actions such as… • __________ • __________ • __________ polymer proteins structural enzymes eating All actions involve ATP!! running thinking
What does DNA stand for? • What eukaryotic organelle contains DNA? Deoxyribonucleic acid The nucleus
Section 11.1 Summary – pages 281 - 287 DNA as the genetic material Before 1950 – scientists thought that ______ contained the genetic information Alfred _________ and Martha ________ conducted an experiment with ____________ to determine if proteins or DNA contained the genetic content proteins Hershey Chase viruses
DNA • Viruses are made up of a ________ coat and a molecule of _______ or ________ protein DNA RNA Protein coat
Viruses may _______ a cell and take over its metabolism, causing it to create more ____________ • But what part of a virus controls this behavior? enter viruses Lytic cycle
Hershey and Chase radioactively ____________ the ________________ and ________ within a virus to see which part entered a bacteria cell… • Result? • Only the _____ entered the bacteria cell and produced new viruses • Conclusion? • _____ must contain genetic material marked protein DNA DNA DNA
Section 11.1 Summary – pages 281 - 287 The structure of DNA DNA is a polymer made of repeating subunits called _______________ nucleotides Phosphate group Sugar (deoxyribose) Nitrogenous base
Section 11.1 Summary – pages 281 - 287 • Nucleotides are made up of 3 parts… • ____________________ • Simple __________ called ______________ • ___________________ phosphate group sugar deoxyribose Nitrogenous base Phosphate group Sugar (deoxyribose) Nitrogenous base
Section 11.1 Summary – pages 281 - 287 • Four possible nitrogenous bases: • ______________ • ______________ • ______________ • ______________ Adenine (A) Guanine (G) Cytosine (C) Thymine (T) Cytosine (C) Guanine (G) Thymine (T) Adenine (A)
Section 11.1 Summary – pages 281 - 287 • In _______, two scientists named James ________ and Francis _______ hypothesized that DNA… • is made of ____ strands or long chains 1953 Watson Crick 2 • and is ______ into a coil like a spring • This structure is called a ________ __________ (twisted zipper) twisted double helix
This shape was supported by the work of Rosalind ___________ • Used X-ray crystallography to make _____________ of DNA • Took as long as _____ hours of exposure to make a single image • She died of _________ , likely related to her X-ray exposure Franklin photos 100 cancer
Section 11.1 Summary – pages 281 - 287 Nucleotides _________ together to make long strands of DNA Circle some nucleotides shown in the diagram join
Section 11.1 Summary – pages 281 - 287 • Each strand has a ________________ made of … • _______________________ • _______________________ • What letter in the diagram represents a phosphate group? _______ • What letter represents deoxyribose sugar? _____ backbone phosphate groups deoxyribose sugars P D
Section 11.1 Summary – pages 281 - 287 • The “teeth” of the zipper are made up of ______________ ______________ • Certain bases always pair together • ___ and ____ • ___ and ____ • Bases that pair together are called ________________ nitrogenous bases C G A T complementary
These bases are held together by weak _____________ bonds that are put together or broken by ______________ hydrogen enzymes
The DNA of all living organisms is made up of the ______ 4 base pairs • Different organisms just have different ___________ or orders of the base pairs Chromosome same sequences
For example, a nucleotide sequence of ATTCGT carries ______________ information from a sequence of ATCGGG • The closer the DNA sequences are, the more ____________ organisms will be different similar
Out of a gorilla, chimpanzee, and a tiger, which two organisms do you think have similar DNA sequences? Why? Gorilla and chimpanzee…more similar organisms.
Section 11.1 Summary – pages 281 - 287 DNA Replication • In order for DNA to be passed on to new cells, it must be copied during ______________ • Three steps to this process! interphase
uncoils • Step 1: The DNA _________ or unwinds 5’ A – T G – C C – G T – A A – T 3’ 3’ 5’
Note that the two sides of DNA run in __________ directions, from 5’ to 3’ and 3’ to 5’. • This helps ensure that the new DNA will copy __________. opposite correctly
opens up complementary • Step 2: The zipper _________...notice that each strand is __________________ to the other A - - T G - - C C - - G T - - A A - - T
Step 3: Free nucleotides come in and make new base pairs A - - T G - - C C - - G T - - A A - - T T A Result? There are ____ new molecules of DNA that are ___________ copies 4 strands = 2 molecules 2 G C exact G C A T T A New strand Old strand Old strand New strand
Since the bases must follow the base-pairing rules, when your body cells ________________, each new cell inherits a ________ of the DNA replicate copy
Review: Section 1 Vocabulary • Nucleotide— • Double helix— • DNA replication— Basic component of DNA molecule with a sugar and phosphate group attached to either Adenine, Guanine, Cytosine or Thymine. Shape of DNA where 2 strands are twisted into a coil and held together by the nitrogenous bases. Process in which an exact copy of DNA is made.
Review: Objective 1 • Analyze the structure of DNA Each DNA molecule is … a coiled Double helix, with a “Backbone” of phosphate and sugar, and “Teeth” made of nitrogenous bases, which can be A, C, G, or T.
Review: Objective 2 • Determine how the structure of DNA enables it to reproduce itself accurately. • The two strands are complementary because the bases must follow the base-pairing rules. Each new strand is a reverse copy of the originals.