1. Protein Synthesis
DNA to Proteins

2. Biochemical DNA –made of 3 component parts Chromosome –DNA + protein
(sugar, phosphate, bases)
Information is stored by the sequences of the bases
Chromosome –DNA + protein
Gene –certain area of chromosome where the bases are sequenced to store information for ONE protein
Protein – made up of number of amino acids

3. Inheritance Genotype – combination of two alleles
Phenotype – expression of a particular trait
Influenced by
Genotype
Environment

4. Biochemical and Inheritance
How does one get from a particular genotype (coded for in the genes) to the expression of it in the phenotype
Connect both biochemical to inheritance
knowing that expression of a traits phenotype is influenced by proteins
sometimes a phenotype = a protein
PKU, albino, ALD

5. Protein Proteins – What do they do? ‘workhorses’ of the cell
Once a protein is synthesized it can combine with other proteins to perform a particular function
Three classes of proteins
Structural – support in the cell like the muscle cell building block, myosin
Regulating proteins - including enzymes and hormones, like the enzyme that breaks down starch molecules, salivary amylase
Transporter proteins – like the oxygen transporter, hemoglobin

6. Protein
They are so important in the cell much of the cellular machinery is concerned with translating the genetic information of DNA into specific proteins.

7. How does information in one section of DNA coding for a particular trait become a protein (sequence of amino acids)?

8. Involves RNA RNA differs from DNA Sugar is ribose (DNA deoxyribose)
One more oxygen in RNA sugar
RNA has the base uracil (DNA has thymine)
Single stranded (DNA double stranded)
RNA is smaller and more of it
RNA can go between nucleus (eukaryotic) and cytoplasm (DNA in nucleus only of eukaryotic)

9. Involves RNA
Three kinds of RNA
mRNA
tRNA
rRNA

10. Two Processes
1) Transcription – synthesis (formation) of an RNA molecule (mRNA) using the genetic information in DNA
Copying DNA to RNA
2) Translation – the actually manufacturing of a protein (putting together amino acids from the information in the mRNA molecule
Using RNA to assemble the polypeptide

11. Generally: How and Where
The genetic information in a particular region of DNA (gene) is TRANSCIBED (copied) to produce a specific molecule of RNA (mRNA)
This occurs in the nucleus
(eukaryotic organisms)

12. Generally: How and Where
The mRNA proceeds from the nucleus into the cytoplasm to a ribosome
Here the information is TRANSLATED into a corresponding specific sequence of amino acid’s to form a newly produced protein molecule (involves tRNA & rRNA)

13. Step 1) Transcription Production of mRNA
mRNA molecules (nucleotides) are put together from the sense strand of DNA
The RNA bases are complementary to the nucleotide sequence of the DNA strand
One substitution thymine is uracil

14. Step 2) Translation
mRNA becomes associated with a ribosome (rRNA) this is where translation occurs.
The ribosome slowly moves along the length of the mRNA molecule
As it moves along the ribosome ‘reads’ the information in the mRNA molecule ‘word by word’
Each word consists of 3 adjacent nucleotides (codon) in the mRNA

15. Continue Translation
Each sequence of 3 nucleotides (codon) triggers the addition of a specific amino acid
Amino acids are bonded by a particular type of bond – Peptide
Many protein bonds = polypeptide chain or a protein

16. Continue Translation tRNA Actually does the translating The Dictionary
Recognizes the codons by having at their ‘business end’ an anticodon
The other end has an amino acid attached to it that is specified for that particular anticodon
Therefore 3 base codon in mRNA specifies a particular amino acid

17. Continue Translation There are 20 amino acids
(the building blocks of proteins)
Each one is signaled by at least one codon, most by several codons
NOTE: most synonyms are identical in their first 2 nucleotides and differ only in their third positions
Important to note for when we discuss miscopying!
NOW PRACTICE!!!