Chapter 9DNA: The Genetic Material

Read 192-198Demo model (student race) Lab Activity from Binder

DNA and RNA Crossword puzzle

DNA/RNA Vocabulary (53-62)

53. anticodon

54. codon

55. base sequence

56. genetic code

57. RNA polymerase

58. transcription

59. translation

60. restriction enzyme

61. DNA replication

62. ribosomal RNA

I. Introduction

• Heredity- The transmission of traits from one generation to the next

• Genetics- The study of heredity, usually at the molecular level.

• Heredity occurs in the form of DNA which is coiled into chromosomes.

• Humans have 46 chromosomes (23 pairs) in each cell. These chromosomes are located in the nucleus of each cell.

DNA coiled into a chromosome

II. HISTORY• Chromosomes have been observed

microscopically since 1850.• Chromosomes are composed of protein and

nucleic acid.• The structure of DNA was discovered by

James Watson (American) and Francis Crick (British)

– Proposed in 1953 the model of DNA as a“DOUBLE HELIX”

– Won the Nobel Prize in Physiology in 1962 for their discoveries

III. DNA

A. DNA Structure

Nucleotide- Repeating unitof DNA

Has 3 parts: Phosphate, deoxyribose sugar and base

Draw and label the structure of DNA

What holds the 2 halves of the ladder together?

A. Processes Involving DNA

1. Replication- See handout in binder• DNA DNA• Each new DNA produced has ½ from the original strand

and ½ that is newly built (semi-conservative).• DNA always stays in the nucleus.• DNA helicase unzips the original DNA during replication

(breaks hydrogen bonds). • DNA polymerase forms the new halves of DNA and

proofread them for errors.• This process occurs once in a cell’s lifetime.

2. Transcription- See handout in binder • DNA code is used as a template to produce

RNA

DNA RNA (single strand)• Only ½ of the DNA is used as a template. This

is called the sense strand. The other is the non-sense strand.

• RNA polymerase builds the strand of RNA.• RNA produced leaves the nucleus to enter the

cytoplasm.• 3 types of RNA are produced: messenger RNA

(mRNA), ribosomal RNA (rRNA) and transfer RNA (tRNA)

IV. Contrasting DNA and RNA

DNA

• 2 strands• Deoxyribose sugar• Remains in Nucleus• Bases

– ATCG – A-T

G-C

RNA

• 1 strand• Ribose sugar• Exits nucleus• Bases

– AUGC

A-U

G-C

Chargraff’s Ratio: #C = #G

#A = #T

3 Types of RNA1. mRNA (messenger)- carries the

DNA’s instructions for making proteins out of the nucleus to the site of translation (cytoplasm)

• Every 3 nucleotides on mRNA is called a codon. Each codon codes for an amino acid.

– See codon table

2. tRNA (transfer)- carries a specific amino acid on one end and an anticodon on the other end. The anticodon complements the codon on mRNA.

Draw the tRNA structure:

3. rRNA (ribosomal)- Along with protein, this makes up the structure of a ribosome.

How Proteins are made (read 205-212)

Translation (protein synthesis)1. Begins when mRNA leaves the nucleus and enters the cytoplasm.

2. mRNA attaches to a ribosome.

3. At the start codon (AUG), a tRNA brings the amino acid into position. When tRNA brings each new AA, it bonds with the adjacent AA by a peptide bond.

4. After amino acids have bonded, the tRNA leaves.

5. This process continues until the STOP codon is reached.

6. The new protein is released.

Draw the translation process

PROTEINS HAVE DEFINITE SHAPES. IF THE SHAPES CHANGE,

THEY WON’T FUNCTION PROPERLY

• DNA code TGA ______________ _______________

• mRNA codon _____________ UCU _______________

• tRNA anticodon _____________ ________________ _______________

• Amino acid ____________ ______________ tryptophan

• DNA code CAT ______________ _______________

• mRNA codon _____________ GUU _______________

• tRNA anticodon _____________ ________________ _______________

• Amino acid ____________ ______________ methionine

After 4 replications of a DNA molecule, what percentage of the resulting DNA molecules contain at least 1 strand of the original DNA?

CP Biology Article Presentation• 4-5 minute summary of article summary• DO NOT READ FROM THE SUMMARY – you can

use note cards if you want• You need at least one visual that will help illustrate

points that you are making in your presentation – posters, powerpoints (4-6 slides….Be creative!)

• If you do not do this correctly, you will have to redo this in front of the class…do it right the first time!

• Do the week of January 23rd- volunteers first• Dress appropriately for giving a presentation

TEST FRIDAY – Test Topics

• Notes on DNA/RNA

• Vocab 62-71

• Reading 192-198, 205-212

• Semi Conservative Replication, Transcription and Translation – Handouts in Binder that we colored…

• DNA/RNA Lab

• Crossword, Text Questions 200,220

NOTEBOOK CONTENTS2nd Quarter Notebook

Check• Cover Sheet • Assignment Sheet • Grade Sheet w/ • Vocabulary 22 (primary

prod.) - 69 (microvilli)• Notes• Systems • Life Processes (Digestive

System pg 83-85)

• Daily Work– Too hot Not to Handle– Ecosystems WS– CH 18 WS pg 57– CH 19 WS Human Impact– Ch 2 Chem of Life– Biochem Crossword– Enzyme WS

• Labs– Pred/Prey Lab

-Beano Lab– Enzyme Computer Lab– Bat Graph

Tot. Pts % Grade

THIS IS 10% OF YOURQUARTER GRADE!!!