DNA

"The Blueprint of Life"

DNA stands for...

D

eoxyribo

N

ucleic

A

cid

DNA FACTS • established by James Watson and Francis Crick • Shape of a double helix

• codes for your genes (traits) • made of repeating subunits called nucleotides

What is a nucleotide?

Has three parts: PHOSPHATE DEOXYRIBOSE (sugar) BASE (A,T,G,C)

Base-Pair Rule Adenine <==> Thymine Guanine <==> Cytosine The sides of the DNA ladder are phosphate & sugar held together by hydrogen bonds

Base Pair Rule One side: A T A T C A Other side: T G C G G G

How the Code Works The combination of A,T,G,C determines what traits you might have.....

C A T C A T = purple hair T A C T A C = yellow hair

Think of the bases of DNA like letters.

Letters form words....

Words form sentences....

*endless combinations

Let's Review What We Know About DNA 1. DNA stands for: De _____ ribo ______ acid 2. What is the shape of DNA? _______________ 3. Who established the structure of DNA? ____________ 4. Adenine always pairs with _______________ 5. The sides of the DNA ladder are deoxyribose and _____ 6. Guanine always pairs with _____________ 7. What is the complimentary sequence: A A T G C A 8. The two sides of DNA are held together by _______ bonds.

9. DNA is composed of repeating subunits called ______________________ 10. What are the 4 bases that make up the rungs of the DNA ladder? _______________________________________

DNA REPLICATION the process by which DNA makes a copy of itself (cell division) SEMI-CONSERVATIVE - half of the old strand is saved

RNA - the messenger *single strand *ribose sugar *contains no thymine, uracil instead *follows base pair rule DNA: A T A G C G RNA:

RNA carries the "message" to the ribosomes, where proteins are made

DNA --> RNA --> Protein Proteins are the building blocks of the organism (traits)

Transcription - process where RNA is made from DNA Translation - process where proteins are made from RNA