Dr. Ramesh U2 L2. Basic structure of DNA and RNA Introduction to Genetics

Transcription

1 Dr. Ramesh U2 L2 Basic structure of DNA and RNA Introduction to Genetics

2 Do Now! Directions: Answer the following questions in complete sentences. 1. Where is DNA located in the eukaryotic cell? 2. Where does your DNA come from? 3. Draw the shape of DNA.

3 Objective! The student will (TSW) explain and model the structure of DNA and identify the nitrogenous base-pairing rule for DNA.

4 Genetics!

5 Genetics! Genetics is the study of how the characteristics (traits) of DNA are passed down to offspring.

6 Genes! Genes are sequences of DNA that code for a specific trait.

7 DNA! DNA (deoxyribonucleic acid) is a molecule that is the genetic code for an organism s traits.

8 What does DNA do?! DNA makes all the proteins that creates traits. When new cells form, they have a copy of DNA passed down from the parent cells.

9 Structure of DNA!

10 Structure of DNA! There are two parts of DNA: 1. The sides (sugar-phosphate groups) 2. The steps (nitrogenous bases) Together, these make up nucleotides (building blocks of DNA).

11 Structure of DNA!

12 Structure of DNA! There are four nitrogenous bases: 1. Adenine (A) 2. Thymine (T) 3. Guanine (G) 4. Cytosine (C)

13 Structure of DNA!

14 BASE PAIRING: CHARGAFF S RULE The four nitrogenous bases are paired like this: A always pairs with T and G always pairs with C

15 Structure of DNA! The ordering of base pairs determines what traits the organism will show.

16 Structure of DNA! A T C C G A

17 Structure of DNA! A T T A C G C G G C A T

18 Twizzler DNA!

19

20 Location Since DNA is the master copy of an organism s genetic code, it must be kept safe so it NEVER leaves the nucleus. DNA in the nucleus is safe But DNA in the cytoplasm can be destroyed

21 Nucleotides The order nucleotides line up in creates a unique genetic code for each organism Only identical twins have the same DNA!

22 2 types of nucleic acids DNA: deoxyribonucleic acid RNA: ribonucleic acid

23 Key Point #1 Nucleic acids are molecules that store and express the genetic code of living things.

24 DNA Nucleotide 1. Phosphate group 2. Sugar: Deoxyribose sugar 3. Nitrogenous bases: A : Adenine T : Thymine G : Guanine C : Cytosine

25 Key Point #2 DNA is the master copy of an organism s genetic code.

26 Key Point #3 Since DNA can t leave the nucleus, it sends the genetic message out into the cell with RNA RNA = RIBONUCLEIC ACID

27 Structure of RNA: RNA has only ONE strand of nucleotides. RNA is SINGLE stranded.

28 RNA vs. DNA -single stranded instead of double -uracil instead of thymine -ribose instead deoxyribose

29 RNA nucleotide 1. Phosphate group 2. Sugar: Ribose sugar 3. Nitrogenous bases - A : adenine - U : uracil - G : guanine - C : cytosine

30 DIRECTIONS Voices at a Level Zero Complete the Guided Practice Copy the following slides in your note books. Raise your hand if you have questions

31 RNA Review RNA DNA and RNA base pairing... loves U

32 Back to building!

33 Build the SINGLE RNA that is complementary to this DNA strand A T T U A A

34 Build the SINGLE RNA strand that is complementary to this DNA strand T C A A G U

35 Build the SINGLE RNA strand that is complementary to this DNA strand A C G U G C

36 Alert: way harder! Build the DNA strand that this RNA strand was copied from A G U

37 Alert: way harder! Build the DNA strand that this RNA strand was copied from A T G C U A

38 Alert: way harder! Build the DNA strand that this RNA strand was copied from C C U

39 Alert: way harder! Build the DNA strand that this RNA strand was copied from C G C G U A

40 DIRECTIONS Voices at a Level Zero Complete the Independent Practice Answer in complete sentences Raise your hand if you have questions

41 DNA v. RNA: DNA RNA # of strands Nitrogenous bases used Type of sugar in backbone What does it do to genetic information? Is it made of nucleotides? Found in nucleus? Cytoplasm? Complimentary strand to DNA of GATTACTACGA? Complimentary strand to DNA of TTTAGGGCCCA T ATGC TWO Deoxyribose Stores it; holds it yes Nucleus only- never leaves CTAATGATGCT AAATCCCGGGTA

42 DNA v. RNA: DNA RNA # of strands TWO ONE Nitrogenous bases used ATGC AUGC Type of sugar in backbone Deoxyribose Ribose What does it do to genetic information? Stores it; holds it Is it made of nucleotides? yes yes Found in nucleus? Cytoplasm? Complimentary strand to DNA of GATTACTACGA? Complimentary strand to DNA of TTTAGGGCCCA T Nucleus only- never leaves CTAATGATGCT AAATCCCGGGTA Takes messages Nucleus, can move into cytoplasm CUAAUGAUGCU AAAUCCCGGGUA

43 You build the complementary strand Structure of DNA! A T C C G A

44 Structure of DNA! A T T A C G C G G C A T

45 You build the complementary strand of RNA Structure of RNA! A T C C G A

46 Independent Practice! Study Guide/Work Book pages 75, 76. Text: Pages

47 Structure of RNA! A U T A C G C G G C A U

48 DIRECTIONS Voices at a Level Zero Complete the Exit Ticket Answer in complete sentences Raise your hand if you have questions

49 Exit Ticket! DIRECTIONS: Copy and answer the following questions. 1) What is the function of DNA? 2) Draw the structure of DNA.