1. DNA and Replication

2. Nucleic Acids: Nucleic acids are made of smaller units called nucleotides. –Each nucleotide has 3 main parts: Phosphate group Sugar Nitrogenous base There are two major types of nucleic acids: DNA and RNA.

3. DNA: A DNA nucleotide will contain the following parts: –Phosphate group –Deoxyribose (sugar) –Cytosine, Guanine, Adenine, and Thymine (nitrogenous bases)

4. RNA: An RNA nucleotide will contain the following parts: –Phosphate group –Ribose (sugar) –Cytosine, Guanine, Adenine, and Uracil (nitrogenous bases)

5. DNA Replication

6.  Replication = DNA copies itself exactly (Occurs within the nucleus during S phase) (Occurs within the nucleus during S phase)  Any mistake in copying = mutation

7. Basic Facts of DNA Replication Complementary base pairing makes replication possible C - G A - T

8. Basic Facts of DNA Replication One side of DNA molecule is a template for making the other side

9. Process of DNA Replication 1. Uncoil & unzip DNA molecule - Enzyme (helicase) breaks weak hydrogen bonds between bases

10. B. Process of DNA Replication 2. Enzyme (DNA polymerase) brings in complementary N-bases

11. B. Process of DNA Replication 3. Enzymes join the new nitrogenous bases together to form a single strand. The original parent strand and the new strand are held together with hydrogen bonds, just like the original DNA strand.

12. Semi-conservative replication Each new DNA molecule contains one old strand & one new strand

14. DNA vs. RNA DNARNA Sugar = deoxyribose Sugar = ribose Double-stranded molecule Single-stranded molecule Thymine bonds with adenine Uracil instead of thymine

15. DNA vs. RNA DNARNA Nuclear DNA Mitochondrial DNA Chloroplast DNA mRNA = messenger tRNA = transfer rRNA = ribosomal Nuclear DNA never leaves the nucleus Assembled in nucleus, moves to cytoplasm (leaves the nucleus)

16. DNA vs. RNA