1. Chapter 3.3
What is DNA?

2. DNA
DNA is a large molecule in chromosomes that has genes for future generation.

3. DNA
DNA carries genes for a future organism. It’s passed from one generation to another. It has a helix shape as a twisted ladder.
Two sides of the DNA are made up of sugar called deoxyribose and phosphate. Between the two sides of the DNA, there are nitrogen bases.

4. DNA There are 4 nitrogen bases in DNA: -Adenine (A) -Thymine (T)
-Guanine (G)
-Cytosine (C)

5. DNA Matching: Adenine with Thymine And Guanine with Cytosine
Example: AAGCTGCCTT
TT C_ _ _ _ _ _ _

6. DNA STRUCTURE

7. DNA replication

8. DNA REPLICATION
DNA REPLICATION means making a copy of DNA before mitosis/meiosis. When it is a time for replication, DNA will “unzip.” The separated strand of DNA will be ready for new nitrogen bases to be paired up. The nitrogen bases follow the rules: A combines with T, and C combines with G. When the replication is finished, one DNA strand will separate and the other will remain with the old strand of DNA.

9. The role of DNA: A DNA molecule has many genes on it
The role of DNA: A DNA molecule has many genes on it. A gene will have thousands of bases (it’s called “genetic code”) that will decide traits (physical appearance) of a future organism.

10. The Structure of RNA:
RNA has only one strand and has Uracil instead of Thymine. The sugar in RNA is ribose instead of deoxyribose.
RNA – A, U, G, C
DNA- A, T, G, C

11. TYPES of RNA:
Messenger RNA (mRNA)- they are messengers from DNA to the rest of cell
Ribosomal RNA (rRNA)-are responsible for making proteins [rRNA and RNA are made of proteins, too)
Transfer RNA (tRNA)- they bring amino acids to the ribosome

12. Difference between DNA and RNA:
What is the difference?
DNA: -double helix
-sugar: deoxyribose
-A, T, G, C
-inside the nucleus
RNA:
-one strand
-sugar: ribose
-A, U, G, C
-outside the nucleus in the cytoplasm

13. Protein Synthesis PROTEIN SYNTHESIS: DNA molecule will make protein:
-for building new cells
-as a part of cell membrane
-as a part of new nails and new hair, etc.
The proteins are made of amino acids.

14. Vocabulary: Replication – DNA to DNA (duplication of DNA)
Transcription- DNA to mRNA
Translation- mRNA to protein synthesis

15. Protein Synthesis - Translation

16. TRANSLATION- protein synthesis:
Translation- During translation, the cell uses information from mRNA to produce proteins.
a. mRNA is transcribed in the nucleus
b. mRNA leaves the nucleus and enters the cytoplasm where it attaches to a ribosome. It starts translation at AUG, the start codon. Each tRNA has an anticodon that matches to a codon on mRNA. Each tRNA brings its own amino acid.

17. Translation (con’t.)
c. The polypeptide “assembly line”- The ribosome breaks the amino acid from its tRNA and joins two and more amino acids together to form a polypeptide chain. The tRNA floats away, allowing the ribosome to bind to another tRNA.
d. Completing the polypeptide- the process continues until the ribosome reaches one of three stop codons. It’ll release a newly formed polypeptide chain.

18. THE GENETIC CODE:
The “language” of mRNA instructions is called the genetic code. RNA has 4 different bases: A, U, C and G. The genetic code is read three letters at a time, so that each “word” of the coded message is three bases long.
For example:
UCGCACGGU
UCG- CAC- GGU
serine-histidine-glycine

19. The Genetic Code ACGUGCAGA ACG-UGC-AGA threonine-cysteine-arginine
amino acid
Examples:
ACGUGCAGA
ACG-UGC-AGA
threonine-cysteine-arginine
CUACCUUGA
CUA-CCU-UGA
leucine-proline-stop
nitrogen bases
on mRNA

20. Protein Synthesis Animations:

21. GENES & PROTEINS:
The role of DNA: A DNA molecule has many genes on it. A gene will have thousands of bases (it’s called “genetic code”) that will decide traits (physical appearance) of a future organism.
Genes for certain proteins can regulate the rate and pattern of growth throughout an organism, controlling its size and shape. In short, proteins are keys to almost everything that living cells do.

22. Questions: List the three main types of RNA.
Messenger RNA (mRNA)- they are messengers from DNA to the rest of cell
Ribosomal RNA (rRNA)-are responsible for making proteins [rRNA and RNA are made of proteins, too)
Transfer RNA (tRNA)- they bring amino acids to the ribosome

23. What are 4 nitrogen bases in DNA?
There are 4 nitrogen bases in DNA:
-Adenine (A)
-Thymine (T)
-Guanine (G)
-Cytosine (C)

24. What are 4 nitrogen bases in RNA?
There are 4 nitrogen bases in RNA:
-Adenine (A)
-Uracil (U)
-Guanine (G)
-Cytosine (C)

25. Describe the three main differences between RNA and DNA.
-double strand
-A, T, G, C
-has sugar called deoxyribose
-stays inside the nucleus (never leaves the nucleus)
-single strand
-A, U, G, C
-has sugar called ribose
-leaves the nucleus to enter the cytoplasm and then attaches to a ribosome to make proteins

26. How are nitrogen bases arranged in a DNA molecule?
In pairs, two bases form a step on the DNA ladder. A will connect with T, C will connect with G.
A - T
C - G
G - C
T- A

27. What is replication?
Replication is a process by which DNA is duplicated (copied).

28. Tryptophan-glutamine-cysteine
Applying concepts: Using the genetic code, identify the amino acids that have the following messenger RNA strand codes: UGG-CAG-UGC.
UGG- CAG- UGC
Tryptophan-glutamine-cysteine

29. Fill in blanks. 1. Proteins are made in ____________.
2. Four nitrogen bases in DNA are ________, ________, __________ and _________.
3. Replication is process by which DNA is ____________.
4. Adenine will connect with ____________, and guanine with ___________.
5. Proteins are made of ______________.
6. RNA’s bases are __________, _________,
____________ and ___________.
7. Three kinds of RNA are ______, ______ and _____.
8. DNA’s sugar is ______________.
9. DNA has many ______________, that are responsible for making ____________.