Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different...

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RNA Another Nucleic Acid

Transcript of Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different...

Page 1: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

RNAAnother Nucleic Acid

Page 2: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

RNA Structure• RNA is the second type of nucleic acid

found in a cell.• There are 3 different types of RNA• Structure of RNA:• Long chain of nucleotides• 5-carbon sugar called ribose• Phosphate• Nitrogen bases- Adenine, Guanine,

Cytosine and Uracil (instead of Thymine)

• Just a single strand

Page 3: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Function of RNA• The function of RNA is to carry the code

from DNA in the nucleus to the ribosomes in the cytoplasm (where the code will be used to make proteins).

Page 4: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Quick Check• Compare the details of DNA to RNA

Feature DNA RNA

# of strands 2 1

Type of sugar Deoxyribose Ribose

Nitrogen bases A, T, G, C A, U, G, C

Location in cell Nucleus Nucleus → Ribosome in cytoplasm

Number of forms 1 3

Job description Carries genetic information

Take info from DNA to the ribosomes to make proteins

Page 5: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Types of RNA• Messenger RNA (mRNA)- this is the piece

of RNA that takes the code (“message”) from the DNA to the ribosome.

• Transfer RNA (tRNA)- this RNA brings (“transfers”) amino acids from the cytoplasm to the ribosome/ mRNA.

• Ribosomal RNA (rRNA)- this is the structural part of a ribosome (a ribosome is only protein and RNA)

Page 6: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Types of RNA

Page 7: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Transcription• Transcription is the process in which a

part (gene) of the DNA is copied into mRNA.

• Players• Piece of DNA• Nucleotides• Enzyme- RNA polymerase

Page 8: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Transcription• What happens:• RNA polymerase finds a sequence called the promoter, binds to the DNA and unzips the strands• RNA polymerase “reads” one strand of the DNA and adds the appropriate complementary RNA nucleotides• The product= a single strand of mRNA

Page 9: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Quick Check• 1. The three types of RNA are _______ , _______

and ______ .• 2. The process of making RNA from DNA is

called ________________.• 3. mRNA has to be made from DNA because

the DNA cannot leave the _________ and the proteins coded for by the DNA are made by the ____________ which are found in the _____________.

• 4. If the sequence of DNA is AGTAGGTCA, what is the mRNA made from it? __________________

mRNA

tRNA

rRNA

transcription

nucleus ribosom

escytoplasm

UCAUCCAGU

Page 10: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

The Genetic Code•Proteins are continuously made by linking together amino acids.•There are 32 different amino acids.•The sequence of nitrogen bases in DNA and mRNA determine the order of amino acids in protein.•Codon= the sequence of 3 nucleotides that codes for a specific amino acid.•Anti-codon= the complementary sequence to the codon; it is found on the tRNA

Page 11: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Codon Chart

Page 12: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Quick Check• Use your amino acid chart to identify the

amino acid that goes with each codon.• 1. AUG ___________________• 2. UGA ___________________• 3. AAA ___________________• 4. GAG ___________________• 5. UCA ___________________• 6. UCC ___________________

Methionine (start)Stop

LysineGlutamat

e SerineSerine

Page 13: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Translation• The sequence of nucleotides in mRNA

provides the instructions to the ribosomes for putting together a protein.

• Translation- the decoding of an mRNA message into an amino acid chain (protein).

• Parts involved:•mRNA• Ribosome• tRNA• Amino acids

Page 14: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Translation• How it’s done:•mRNA attaches to a ribosome in the cytoplasm• The codon on the mRNA is “read” by the ribosome.• The ribosome brings in the correct anti-codon with an amino acid attached.• The anti-codon of the tRNA matches up with the codon on the mRNA.

Page 15: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Translation• The second codon is “read” and the ribosome brings

in the next tRNA.• A peptide bond forms between the amino acids on

the 2 tRNA’s in the ribosome.• The first tRNA loses its amino acid and it leaves the

ribosome.• The ribosome slides along continuing the process until

a STOP codon is reached.

Page 16: Another Nucleic Acid. RNA is the second type of nucleic acid found in a cell. There are 3 different types of RNA Structure of RNA: Long chain of nucleotides.

Quick Check• Complete the remaining Quick Check in your

notes. We will go over the answers in 15 minutes.• http://www.online-stopwatch.com/countdown-time

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