1. Bell Work
GCCTTA
What would be the DNA compliment of the section of DNA above?
a. CGGAAT
b. CGGUUT
c. ATTCCG
d. TAAGGC

2. Question 1. Which of the following is NOT true about DNA replication?
It occurs during interphase
The new DNA is identical to the original DNA
It is semi-conservative
The sequence of the nucleotides is changed

3. Question 2. DNA contains genetic information on its ___.
Hydrogen bonds
Deoxyribose sugar
Nucleotide sequence
Phosphate bonds

4. Question
3. Which of the following is true about the relationship between DNA, genes, and chromosomes?
Chromosomes and proteins make up genes and genes make up DNA
Chromosomes are made up of DNA and protein. Genes are sections of DNA on a chromosome
Genes and proteins make up DNA. The sequence of genes and proteins make up a chromosome.
Proteins make up chromosomes and DNA. DNA and chromosomes make up genes.

5. Notes Proteins control all the processes of the cell
DNA controls the production of every protein
To be made correctly, 3 processes must occur
1. DNA replication
2. transcription
3. tanslation
If the nucleotide sequence changes, then the information that it carries will change

6. Notes DNA Made of nucleotides 1953: Crick and Watson
3 parts of a nucleotide
Sugar (deoxyribose)
phosphate group
nitrogen bases (complimentary pairs: A-T, C-G)
1953: Crick and Watson
Discovered that DNA was made of two nucleotide chains joined at the nitrogen bases by hydrogen bonds.
Discovered that it was a twisted helix

7. Notes
The more closely the DNA sequences are between two organisms, the more similar they are.

8. DNA Chromosomes are made of proteins and DNA
Genes are the sections of DNA that provide information about specific traits.

9. Notes:
Replication, Transcription and Translation allow an organism to express its inherited genes.

10. DNA Replication DNA replication The process by which DNA copies itself
Takes place during interphase
An exact replica of the DNA is made

11. Step 1 of DNA Replication
An enzyme breaks the hydrogen bonds between the nitrogen bases causing the DNA to “unzip”, exposing the nitrogen bases

12. Step 2 of DNA Replication
Nucleotides that are floating around in the cell (free nucleotides) pair with the exposed nitrogen bases
This type of replication is called “semi-conservative” since the new molecules of DNA will have one side of the original DNA and the other side will be formed new from free nucleotides.

13. Step 3 of DNA Replication
The sugar and phosphate parts of the free nucleotides bond together to form a complete strand that will make up the new side of the DNA molecule
The original strand bonds to the new strand

14. Step 4 of DNA Replication
The result is two molecules of DNA that are identical since the base pairs have to join their complimenting nitrogen base

15. Transcription and Translation
RNA
Consist of the sugar ribose, instead of the deoxyribose sugar of DNA
Pairs A to U instead of A to T
Single strand instead of double strand
3 types: messenger RNA (mRNA), transfer RNA (tRNA) and ribosomal RNA

16. Why RNA is needed
Proteins are made on the ribosomes in the cell, but the DNA (instructions) are located in the nucleus
Information from the DNA must be sent to the ribosomes…..TRANSCRIPTION

17. Transcription Transcription
A process that copies the instructions in the DNA onto a strand of mRNA

18. Notes: Steps in Transcription
DNA unzips like it did in replication
Free RNA nucleotides pair with the nitrogen bases
Adenine (A) pairs with uracil (U)
Cytosine (C) still pairs with guanine (G)

19. Notes: Steps in Transcription
Base pairing finishes
mRNA breaks away from the DNA strand
2 DNA strands zip back together
The mRNA goes out of the nucleus and into the cytoplasm of the cell

20. Notes: mRNA
Codons
Nitrogen bases in the mRNA also forms groups of three bases called codons
The code for an amino acid
64 different combinations of 3 bases are possible.
These combinations make up the codes for the twenty different amino acids
Combinations of the 20 amino acids make up proteins in all organisms

21. Notes: Translation Translation The process that builds proteins
Takes place after the ribosomes attach to the mRNA
The mRNA attaches to the rRNA and “reads” the sequence 3 bases at a time

22. Notes Transfer RNA (tRNA) is used to carry amino acids to the ribosome
Has a three nucleotide sequence called an anticodon
Anticodons form base pairs with the codons of the mRNA

23. Notes: Translation
tRNA carries a specific amino acid that was determined by the anticodon sequence
A bond forms between the two amino acids.
The tRNA is released

24. Notes: Translation continued
Process repeats itself over and over and a chain of amino acids is built
When the rRNA reads a special stop codon, translation stops and the chain is released into the cytoplasm
The polypeptide may then be used in cellular processes OR it may bond with other polypeptides to form proteins

25. Notes
Proteins

26. Notes
Proteins

27. Notes
Proteins

28. Notes
Proteins