DNA, RNA, to Protein

So far, we have discussed

DNA DNA • This was called _______________. • The basic idea is that we are copying the DNA.

But, how does DNA store hereditary information?????

• DNA stores all of the instructions needed to make all of the proteins in an organism.

Its makes you, who you physically are!!!!

The Flow of genetic information in cells:

DNA RNA protein Location:

Nucleus nucleus to cytoplasm cytoplasm

What is RNA??– A nucleic acid

STRUCTURE– Single stranded– Sugar is ribose– Nitrogen bases

• Adenine – Uracil• Cytosine – Guanine

Journal: How is RNA structurally different from DNA?

What are some differences between RNA and DNA?

RNA DNA

1. Sugar is ribose

2. One strand

3. Uracil

4. Can be found in the nucleus or the cytoplasm

1. Sugar is deoxyribose

2. Two strands

3. Thymine

4. Can only be found in the nucleus

3 types of RNA 1. mRNA (messenger RNA)

– Sends information from DNA in the nucleus to the cytoplasm

2. rRNA (ribosomal RNA)– Assembles the amino acids to make proteins

3. tRNA (transfer RNA)– Delivers amino acids to the ribosome

What is Protein Synthesis and where does it take place?

• The making of proteins and it takes place on the ribosomes

DNA RNA protein step 1 step 2

Step 1: Transcription - DNA to RNA Step 2: Translation- RNA to Proteins

Transcription• The process of creating an RNA copy from

DNA• Where does Transcription take place?The nucleus

How does Transcription happen?1. In the nucleus, enzymes unzip a part of DNA

that is to be transcribed2. RNA nucleotides that are complementary to

the DNA strand pair up. 3. The RNA nucleotides bond to each other

creating a single strand4. The RNA breaks away and heads for the

cytoplasm5. The DNA zips back up.

RNA Processing

Not all parts of DNA carry information (give direction for making protein)

Introns: Non-coding parts of DNAExons: Coding parts of DNA

New RNA contains both parts, Introns and Exons, but the Intron are removed before the mRNA leaves the nucleus! (This is RNA Processing)

The mRNA message• Codon: group of 3 nucleotides in mRNA that

codes for 1 amino acid.

What does the RNA codonAUG code for?

Translation

• The process of converting the mRNA message into an amino acid sequence (protein)

Where does Translation take place?On ribosomes in the cytoplasm

What joins the amino acids together to form a protein?

• A peptide bond joins amino acids to make a polypeptide chain.

Where do the amino acids come from floating in the cytosol of our

cells?

• The food we eat (proteins)

What are some important proteins that we make?

Functional Proteins1. Hemoglobin -found in our red blood cells;

function in carrying oxygen2. Antibodies -help fight off viruses and

bacteria that invade the body.3. Enzymes -control chemical reactions in the

body.

What are some important proteins that we make?

Structural Proteins1. Keratin -water proofing protein on our skin.2. Actin and Myosin -proteins which make up

our muscles3. Collagen- found in cartilage and other

connective tissue

Journal• What are the DNA to RNA base paring

rules????

• DNA to RNA• A U• T A• C G• G C

Transcription/ Translation Practice

• Transcribe the DNA to RNA• Translate the resulting RNA sequence into the

amino acid sequence

DNA: TAC AAA GCT TCA GGC CCT GAT ATCmRNA: AUGAminoAcids:

Transcription/ Translation Practice

• Transcribe the DNA to RNA• Translate the resulting RNA sequence into the

amino acid sequence

DNA: TAC AAA GCT TCA GGC CCT GAT ATCmRNA: AUGAminoAcids: MET

Transcription/ Translation Prcatice

• Transcribe the DNA to RNA• Translate the resulting RNA sequence into the

amino acid sequence

DNA: TAC AAA GCT TCA GGC CCT GAT ATCmRNA: AUG UUU CGA AGU CCG GGA CUA UAGAmino

Acids: Met Phe Arg Ser Pro Gly Lue Stop

Time to practice!!!!