DNA STRUCTURE 3.3.3 page 63-74 What are the monomers of the nucleic acids? What are the elements...

DNA STRUCTURE 3.3.3page 63-74

• What are the monomers of the nucleic acids?

• What are the elements found in the nucleic acids?

Where is DNA found in a prokaryotic cell? In eukaryotic cell

STRUCTURE OF NUCLEIC ACIDS

• Types of nucleic acids:

Polynucleotide 3.3.3

Structure of nucleotide 3.3.1

Types of nucleotides 3.3.2

How is polymer of nucleic acids formed?

What are the chemical bonds between them?

Nucleoside

phosphate

ribose

Nitrogeneous base

.

Double helix

DNA (deoxyribonucleic acid)

• Functions of the DNA:

1-

2-

3.4. Replication of DNA1-

2-

3-

4-

* This process is called semi-conservative replication. Why?

DNA replication 3.4

3.4

3.5 Ribonucleic acid

3.5 Nitregenous bases

mRNA (messenger RNA):

tRNA (transfer RNA):

rRNA (ribosamal RNA)

3.5 Transcription, translation

3.5 How does DNA control cellular activities?

• How does Mr.Du Rand control school activities?

1-

2-

• How does the information in DNA lead to the synthesis of specific proteins? How is the information in DNA transported from the nucleus to the cytoplasm?

Language of life

• There are 4 letters in the language of DNA (A,G,T,C)

• Three letters form a word such as AAA, GTA ….. There are 64 different words in this language.These triplet nucleotides (words) are called genetic code.

• 61 genetic codes code amino acids, 3 of them do not code.

Transcription:

1-

2-

3-

4-

Language of RNA

• mRNA takes genetic information from DNA by transcription.

• The letters of RNA are A, G, C, U. Three letters form a codon which codes an amino acid.

• There are 64 different codons, only 61 code amino acids, 3 of them do not code amino acid.

DNA has AAGTCGCTCACC sequence

mRNA has UUCAGCGAGUGG sequence

There are 64 different codons on mRNA.

What is the amino acid sequence of a polypeptidewhich is produced from thismRNA?

Translation

tRNA molecules transfer amino acids according to codon anti-codon recognition.

3.5.5. One gene-one enzymepage 71-74

In the past it is believed that each gene codes an enzyme. This hypothesis is called one gene-one enzyme.After further researches, one gene one enzyme hypothesis is modified as one gene one polypeptide

Each gene works by coding for the synthesis of one particular protein, such as an enzyme.

Questions:

• A DNA strand has AAGTCCGCTTAA nucleotide sequence.1- What will be nucleotide sequence of the complementary

strand of this DNA strand?2- What will be nucleotide sequence of the mRNA which is

transcribed from this DNA strand?3- What would happen to the DNA strand after transcription?