Do you know what this is?

DNA Stands for Deoxyribose Nucleic Acid It is a long molecule called a polymer Shape: double helix

DNA Located: nucleus of eukaryote cell Made up of repeating units of nucleotides

DNA has 3 Basic Parts 5-Carbon Sugar called Deoxyribose Phosphorous group Nitrogenous Base A 5-carbon sugar, phosphate, and nitrogenous base is called a nucleotide

A Nucleotide

Nitrogenous Bases 4 Types of Nitrogenous Bases They are: Adenine, Thymine, Guanine, and Cytosine Nitrogenous bases are “complimentarily paired”

Complementary Bases Adenine (A) always pairs with Thymine (T) Guanine (G) always pairs with Cytosine (C)

What is the complimentary strand of this sequence? A-T-G-C-A-T-A-C-G-A-T-T-A-G-C T-A-C-G-T-A-T-G-C-T-A-A-T-C-G

Double Helix 2 strands twisted around each other Each strand is made up a chain of nucleotides Strands are held together by Hydrogen Bonds between nitrogenous bases

Chromosomes: DNA is on Chromosomes in the form of Genes

GENES: 1) Small portions of DNA 2) Found on Chromosomes *add* Gene-chromosome theory is that genes are on chromosomes

STOP

STEP 1: DNA UNZIPS into 2 strands This structure is a Replication Fork DNA Replication

Replication Fork- when it opens up

Template (STEP 2) An enzyme takes free nucleotides and attaches them to the exposed strands of DNA The Original strand of DNA acts as a template for the new strand of DNA

New Strand

DNA Unzips Use Old Strands as a template

How does DNA Replicate DNA uses enzymes to replicate DNA enzymes “unzip” the two strands The principal enzyme used is DNA Polymerase

DNA Polymerase Polymerizes individual nucleotides to produce DNA Also Proofreads It’s an enzyme

STEP 3 You end up with 2 strands of DNA

STOP

DNA codes for Proteins Proteins become enzymes, and are what genes express Protein Synthesis

Building blocks: amino acids Their shape determines their function Proteins are polymers of amino acids *Polymers are long chains Proteins Refresher

It is a nucleic acid just like DNA It is single stranded, it’s sugar is Ribose, and has 4 Nitrogenous bases. RNA: Ribonucleic Acid

4 Nitrogenous Bases Adenine Uracil (NOT THYMINE) Guanine Cytosine

DNA: A-T-G-T-T-A-A-A-A-G-C RNA: U-A-C-A-A-U-U-U-U-C-G RNA still follows the complementary base pairing, BUT SUBSTITUTES U FOR T Practice Converting DNA to RNA

mRNA (Messenger RNA) rRNA (Ribosomal RNA) tRNA (Transfer RNA) 3 Types of RNA

1. mRNA: Messenger RNA JOB: Carries a copy of DNA from the nucleus to the ribosome

JOB: Clamps onto mRNA and uses its information to make amino acids 2. rRNA: Ribosomal RNA

Job: transfers amino acids to ribosome 3. tRNA: TRANSFER RNA

m in mRNA is for Messenger t in tRNA is for Transfer

Ribosome

stop

2 stages 1) Transcription 2) Translation Protein Synthesis

WAIT, WHAT DOES SYNTHESIS MEAN?

1. WHERE: NUCLEUS 2. WHAT: DNA double helix unzips 3. WHO: mRNA TRANSCRIPTION

Transcription 1. mRNA copies the DNA code 2. mRNA leaves the nucleus and brings the code to a ribosome 3. Similar to DNA Replication, but RNA is single stranded and uses U instead of T

Ribosome On it’s way to ribosome mRNA leaves

EX: mRNA DNA: A-T-G T-C-A mRNA: U-A-C A-G-U RNA-NO THYMINE!

Genetic Code EVERY 3 Nucleotides code for 1 Amino Acid EX: U-U-U codes for Phenylalanine Each set of 3 nucleotides in mRNA is called a CODON

There are Codons that STOP and START the production of Proteins

1. WHERE: Cytoplasm and ribosomes 2. mRNA molecule attaches to a ribosome 3. As each codon of the mRNA moves through the ribosome,the proper amino acid is brought in by tRNA an attached to the mRNA. 2. Translation

Translation 1. The anticodon on tRNA matches the codon of mRNA. 2. mRNA continues to move through the ribosome and tRNA continues to add amino acids.

What’s an Anticodon? It is the complement of the Codon Remember the codon is 3 nucleotides from mRNA

mRNA Codon: U-U-U tRNA ANTI-CODON A-A-A

Carries the Anticodon on one end An Amino acid is located on the other end of tRNA tRNA