1. Aim: How does a chromosome code for a specific protein ?
HW read pages
Answer ques. #1-5
section 12-3 pg 306

2. DNA is made up of chains of nucleotides
Hydrogen bonds
The order of the bases is important in the production of a specific protein. A portion of the DNA codes for a specific protein.
Remember there are 22 pairs of autosomes and 1 pair of sex chromosomes that all contain codes for specific proteins.
Sugar-phosphate backbone
Key
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
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3. DNA makes RNA - Transcription
Adenine (DNA and RNA)
Cystosine (DNA and RNA)
Guanine(DNA and RNA)
Thymine (DNA only)
Uracil (RNA only)
The strand of RNA produced has complimentary base pairs along the ribose-phosphate backbone. It is different in that Uracil replaces Thymine in the sequence of bases. Only mRNA leaves the nucleus.
RNA polymerase
DNA
RNA
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4. RNA makes Protein Questions to ponder:
1. When does replication occur? (Mitosis or Meiosis)
2. When does transcription occur? (copy of gene is made for production of protein)
What kind of RNA is involved in translation? (tRNA carries the code for amino acid)

5. Three types of RNA mRNA, rRNA, tRNA
Nucleus
Messenger RNA .
mRNA
Amino acid
Amino Acids
tRNA
There are three main types of RNA
Messenger RNA (mRNA) produced in the nucleus from DNA
Ribosomal RNA – structure of the ribosome in the cytoplasm of the cell
Transfer RNA (t RNA) transfers amino acids to the ribosome as it is specified by the coded message in mRNA to produce a protein
Ribosomal RNA
mRNA
Codon
Section:

6. Importance of Base Sequence
DNA has the following sequence of nucleotides
GACAAGTCCACAATC
mRNA
Write the code for messenger RNA
CUGUUCAGGUUGUUAG

7. CODON – 3 nucleotides on mRNA that specify a particular amino acid
m RNA CUGUUCAGGUGUUAG
t RNA
T RNA bases are complimentary to mRNA bases
GAC AAG UCC AAC AAU CGG

8. The Genetic Code GAC AAG UCC AAC AAU CGG Section 12-3
The Genetic Code shows the amino acid to which each of the 64 possible codons corresponds. To decode a codon, start at the middle of the circle and move outward.
What is the sequence of amino acids for this protein?
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9. Proteins are made from amino acids
A total of 9 amino acids are considered essential (must be ingested), while another 11 or so nonessential can be synthesized by cells.
Essential amino acids : Histidine, isoleucine, Leucine, lysine, methionine phenylalanine, threonine tryptophan, and valine
Nonessential amino acids: Alanine, arginine, aspartic acid, cystine, glutamic acid, glycine, proline, serine, and tyrosine

10. Importance of polypeptide chain  protein
Section 12-3
The Polypeptide “Assembly Line”
Growing polypeptide chain
Ribosome
tRNA
Lysine
tRNA
mRNA
Completing the Polypeptide
mRNA
Translation direction
Ribosome
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11. Importance of protein synthesis
The cell goes to a lot of trouble to synthesize proteins correctly because proteins define what the cell looks like, how it functions, how it grows, and how it passes this information to its daughter cells

12. Which statement best expresses the relationship between the three structures represented below?
(1) DNA is produced from protein absorbed by
the cell.
(2) Protein is composed of DNA that is produced
in the cell.
(3) DNA controls the production of protein in
(4) Cells make DNA by digesting protein.

13. The diagram below shows some of the steps in protein synthesis.
The section of DNA being used to make the strand of mRNA is known as a
(1) carbohydrate
(2) ribosome
(3) gene
(4) Chromosome
The site of protein synthesis is the
Answers: gene, ribosome

14. The types of human cells shown below are different from one another, even though they all originated from the same fertilized egg and contain the same genetic information.
Different genes are turned on that signal the cell to produce proteins that make the cell specialized.
Explain why these genetically identical cells can differ in structure and function.