November 16GRADING PEN! Each ANSWER = 1 ptGrade Study guide homeworkNotes Ch. 12-1 and 12-2 (right side)

HW – DNA/RNA coloring wksheet

DNAdeoxyribonucleic acid

: The Blueprint of Life

Where have scientists been?

Avery, Oswald (1944) Discovered that the nucleic acid -

DNA stores and transmits the genetic information from one generation of an organism to the next

ALFRED HERSHEY & MARTHA CHASE (1952) CONCLUDED THAT THE GENETIC MATERIAL

OF THE BACTERIOPHAGE WAS DNA, NOT PROTEIN

USED RADIOACTIVE PHOSPHOROUS AND SULFUR

Chargaff, Erwin discovered a relationship

in the nitrogenous bases ADENINE (A) = THYMINE (T)

GUANINE (G) = CYTOSINE (C)

Rosalind Franklin (1952) TOOK AN X-RAY OF THE DNA

STRUCTURE SO THE PATTERNS COULD BE SEEN

THE X-RAYS SHOW THAT DNA IS TWISTED AROUND EACH OTHER LIKE A HELIX AND HAS 2 STRANDS

Watson and Crick (1953) STUDIED THE STRUCTURE OF DNA BY

BUILDING A 3-DIMENSIONAL MODEL OF THE MOLECULE AFTER USING CLUES FROM FRANKLIN’S X-RAY OF DNA.

Watson and Crick (1953) proposed that DNA is made up of 2

chains of nucleotides held together by nitrogenous bases & that the 2 strands are twisted together in a shape called a double helix.

DNA is a polymer made up of repeating monomers of nucleotides. DNA determines an organism’s traits by controlling the manufacturing of specific proteins. The sequencing of nucleotides forms unique genetic information.

The Structure of DNA

The nucleus of a cell contains chromosomes

Which are

made up of coiled DNA

Eukaryotic chromosomes contain DNA wrapped around proteins called Histones.

Each strand of DNA is made up

of subunits called

Each nucleotide is constructed of 3 parts:

a PHOSPHATE group,a SUGAR molecule,

&

1 of 4 nitrogen bases

Adenine (A)

Guanine (G)

Cytosine (C)

Thymine (T)

purines

pyrimidines

Because of the hydrogen bonds,

Adenine can only bond with Thymine

&

Guanine can only bond with Cytosine

e

e

e

e

*A purine is always paired with a pyrimidine.*

http://www.biology.washington.edu/fingerprint/dnapair.gif

This is known asCOMPLEMENTARYbase pairing

For example: TCG AAC TGG AGC TTG ACC

You try: CCA GAT TGA

GGT CTA ACT

DNA Replication

Copying process by which a cell duplicates its DNA

DNA molecule separates into two strands, then produces two new complementary strands following the rules of base pairing Each strand of the double helix of

DNA serves as a template for the new strand

How Replication Occurs

Enzyme – DNA Helicase unzips DNA by breaking the hydrogen bonds between the base pairs, which produces two replication forks DNA polymerase Joins individual nucleotides to make

a new strand Proofreads each new strand

RNA & Protein Synthesis

DNA remains in the nucleus, but in order for it to get its instructions translated into proteins, it must send its message to the ribosomes where proteins are made. The chemical used to carry this message is Messenger RNA.

RNA = ribonucleic acid 3 Types of RNA:1.      mRNA= Messenger RNA: FX: Carry the genetic information out of the nucleus for protein synthesis2.      tRNA= transfer RNA: FX: decode the information by transferring the amino acid to the ribosome as it is specified by coded messages in mRNA3. rRNA= Ribosomal RNA: constitutes 50% of a ribosome, which is the site of protein synthesis.

RNA is similar to DNA except:

1. has one strand instead of two strands.

2. has uracil instead of thymine.

3. has ribose instead of deoxyribose.

mRNA has the job of taking the message from the DNA to the nucleus to the ribosomes.

Transcription - RNA is made from DNA

Translation - Proteins are made from the message on the RNA