DNA and RNA Replication Transcription and Translation 1122020

DNA and RNA Replication, Transcription and Translation 11/2/2020 SB 2 b 1

SB 2 b o Students will analyze how biological traits are passed on to successive generations. b. Explain the role of DNA in storing and transmitting cellular information 11/2/2020 SB 2 b 2

Essential Question o What is the role of DNA in the process of passing biological traits from one generation to the next? 11/2/2020 SB 2 b 3

REPLICATION 11/2/2020 SB 2 b 4

Replication of DNA o DNA has to copy itself because when new cells are made, the cell has to have an exact copy of the DNA. o This occurs during the cell cycle in the S phase. o This process is called Replication n 11/2/2020 It is considered semiconservative SB 2 b 5

Replication continued o Replication begins with DNA untwisting itself and opening up n DNA Helicase p Responsible for unwinding the molecule o The old DNA strands = templates o New nucleotides come and bond to the template creating a new strand = Complementary Strand n DNA Polymerase p Responsible for adding nucleotides p Forms covalent bond between nucleotides n 11/2/2020 DNA ligase binds the two new strands SB 2 b 6

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11/2/2020 SB 2 b Taken from concepts in motion Glencoe CD 9

Replication continued o DNA is read in parts n It does not start at the beginning and go all the way to the end, that would take too long o Replication can start at many points in eukaryotes 11/2/2020 SB 2 b 10

Replication continued o DNA is “proof read” by enzymes n The enzymes fix any mistakes p DNA n polymerase Mistakes not fixed will cause problems p We will discuss the problems when we get to human genetics 11/2/2020 SB 2 b 11

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Practice Replication 11/2/2020 n TTGCTAG n TAGCGCT n ACCGTCA n GCTATGT SB 2 b 13

Central Dogma 11/2/2020 SB 2 b 14

Central Dogma o The central dogma states that information flows in one direction from DNA to RNA to proteins. 11/2/2020 SB 2 b 15

TRANSCRIPTION 11/2/2020 SB 2 b 16

Transcription o Transcription is the process of m. RNA copying DNA n n This is how new m. RNA is made Copies a gene and can make many copies o This occurs in the nucleus o Occurs just like replication but with RNA instead n Only one side of the DNA is copied n Enzyme – RNA Polymerase 11/2/2020 SB 2 b 17

Practice Transcription o. T T G C T A G o. T A G C T o. A C C G T C A o. G C T A T G T 11/2/2020 SB 2 b 18

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11/2/2020 SB 2 b Taken from concepts in motion Glencoe CD 20

TRANSLATION 11/2/2020 SB 2 b 21

Translation o a/k/a Protein Synthesis o DNA is ultimately a code for protein production o Proteins in turn make up all the parts of cells which will then control all chemical processes o Proteins are made up of Amino Acids 11/2/2020 SB 2 b 22

Translation 11/2/2020 1. m. RNA transcribes the DNA (gets the message/code) 2. m. RNA carries the message from the nucleus to the ribosomes (on the ER) 3. r. RNA inside the ribosomes reads the m. RNA SB 2 b 23

Translation continued 11/2/2020 4. r. RNA tells t. RNA which Amino Acids are needed 5. t. RNA collects and brings back the Amino Acids 6. r. RNA hooks together the Amino Acids into a protein SB 2 b 24

Codons o Every 3 nitrogen bases on the m. RNA = Codon n A codon is a code for an Amino Acid or start and stop codons. p Start Codon: AUG (needed for process to begin) p Stop Codons: UAA, UGA, UAG o On the t. RNA is an anticodon – it is complementary to the codon o Example: Codon UUU, Anticodon AAA o Practice: Codon CGC, Anticodon 11/2/2020 SB 2 b 25

The genetic code matches each RNA codon with its amino acid or function. 11/2/2020 SB 2 b 26

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