1. DNA
Structure

2. DNA Structure
DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix.
A molecule of DNA is made up of millions of tiny subunits called Nucleotides.
Each nucleotide consists of:
A Phosphate group
A sugar
A Nitrogenous base

3. The Structure of A Nucleotide
Phosphate
Nitrogenous
Base
Pentose
Sugar

4. DNA is Structured like a Ladder
The phosphate and sugar molecules form the backbone of the DNA molecule
the bases form the “rungs”.
The “rungs” are made from Nitrogen Bases

5. The Four Types of NucleotidesA
Adenine T
Thymine C
Cytosine G
Guanine

6. The Nitrogen Bases Form a base pair. Form a base pair.
Each base will only bond with one other specific base.
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
Form a base pair.
Form a base pair.

7. DNA Structure
Because of this complementary base pairing, the order of the bases in one strand determines the order of the bases in the other strand.
If you have a strand that is ATGC, the complementary strand will be ?
Answer: TACG

8. A C T G G A T C

9. A Look At The DNA Code
To crack the genetic code found in DNA we need to look at the sequence of bases.
The bases are arranged in triplets called codons.
A G G - C T C - A A G - T C C - T A G
T C C - G A G - T T C - A G G - A T C

10. Deciphering The Genetic Code

11. Going from DNA to Proteins
A gene is a section of DNA that codes for a protein.
Each unique gene has a unique sequence of bases.
This unique sequence of bases will code for the production of a unique protein.
It is these proteins and combination of proteins that give us a unique phenotype.

12. What are Chromosomes? Chromosomes are condensed bundles of DNA.
Long thin stands of DNA (chromatin) are wrapped around protein molecules (histones) to form organized bodies of DNA = Chromosomes

13. DNA
Gene
Protein
Trait

14. The Central Dogma of Biology

15. DNA Replication
During DNA Replication, DNA copies each strand of the DNA molecule.
Each stand is copied which results in two identical copies

16. What Is RNA? RNA is also a Nucleic Acid There are three types of RNAs
It is a single stranded molecule
Uracil replaces thymine
The Sugar is Ribose
In DNA, sugar is Deoxyribose
There are three types of RNAs
mRNA
tRNA
rRNA
RNA Stands for RiboseNucleic Acid

17. The Structure of RNA?

18. The Different Forms of RNA
Each form of RNA has a very specific and different Job

19. Why Do We Need RNA?
The genetic Code from DNA is transcribed into the RNA Code
RNA carries the genetic information from the nucleus out into the cytoplasm
Messenger RNA (mRNA) brings the genetic code to the Ribosomes, where the protein will be made

20. The Central Dogma of Biology

21. The Process of Transcription

22. Transcription: From DNA to RNA
If the nitrogen bases on the DNA molecule are: A T G C
Then the RNA Stand would be U A C G

23. The Process of Transcription
mRNA is made and leaves the Nucleus

24. The Process of Translation
mRNA attaches to a ribosome
Translation begins at the AUG, start codon.
The anticodon of the tRNA binds to the complimentary codon on the mRNA
The corresponding amino acid is attached to the tRNA molecule

25. The Process of Protein Synthesis
The ribosomes join the two amino acids together forming a peptide bond.
The tRNA floats away from the ribosome and binds to its specific amino acid
The ribosome advances along the mRNA strand binding new amino acids together

26. Translation: The Final Product
The process continues until the ribosome reaches one of the three stop codons.
The result is a complete polypeptide = protein

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