Presentation is loading. Please wait.

Presentation is loading. Please wait.

RNA A nucleic acid which acts as a messenger between DNA and the ribosomes to carry out the process of making proteins from amino acids. Structure is similar.

Similar presentations


Presentation on theme: "RNA A nucleic acid which acts as a messenger between DNA and the ribosomes to carry out the process of making proteins from amino acids. Structure is similar."— Presentation transcript:

1 RNA A nucleic acid which acts as a messenger between DNA and the ribosomes to carry out the process of making proteins from amino acids. Structure is similar to DNA

2 http://www.genome.gov/P ages/EducationKit/downlo ad.html#3dvid Short video clip introducing translation.

3

4 RNA vs. DNA 1. Type of Sugar: Sugar in RNA=Ribose Sugar in DNA= Deoxyribose 2. Structure: RNA=single strand of nucleotides DNA= double helix (2 strands of nucleotides) 3. Nitrogenous Bases: RNA= Adenine-Uracil Cytosine-Guanine DNA= Adenine-Thymine Cytosine-Guanine 4. Function

5 RNA Consists of nucleotides: 1. Sugar= ribose 2. Base 3. Phosphate **only one strand** A U C G

6 Types of RNA rRNA - Ribosomal RNA: makes up the ribosomes: the organelles that help make proteins tRNA - Transfer RNA: Brings amino acids to ribosomes during translation (protein synthesis). mRNA - Messenger RNA: Helps make proteins by directing which proteins are made.

7 Transcription Defined: RNA synthesis= the unzipping of the DNA strands and synthesis of an RNA; by RNA polymerase(enzyme) and using one of the DNA strands as a template. Transcription (making RNA) : WHY is transcription needed? DNA stays in the nucleus so it needs a messenger like RNA, to carry the genetic information outside the nucleus.

8 Transcription and Translation Learning Goal: Describe the process and purpose of transcription and translation and how these processes create a protein.

9 Transcription First Step: RNA polymerase binds to a promoter on the DNA. A promoter is a sequence which RNA polymerase recognizes and signals the starting point of transcription. This first step is called Initiation : RNA polymerase binds to a promoter

10 Elongation: RNA polymerase synthesizes a new complimentary RNA strand. Base pairing is done with DNA according to the rules, except U pairs with A, instead of T. U – uracil

11 Termination: Transcription continues until the RNA polymerase reaches a specific sequence of DNA, that signals RNA polymerase to release both the DNA molecule and the newly made single- stranded RNA molecule. In eukaryotes: the most common termination sequence is AATAAA.

12 In eukaryotes, the new RNA molecule is actually called pre-m RNA. It contains large segments of DNA that do not code for any proteins. These non-coding segments of DNA are called introns These introns are spliced out and the remaining segments of RNA are cut and pasted together. The segments of DNA that code for proteins are called exons.

13 Transcription

14 Transcription=animated

15 Codon: 3 nucleotide segment of m RNA that codes for a specific amino acid.

16 Translation: (Protein Synthesis)=decoding of m-RNA into amino acids to form proteins

17 Amino Acids =subunits of Proteins or polypeptides

18 Amino Acids: 20 different amino acids

19 M-RNA Strand t-RNA:

20 Translation: the conversion of mRNA code into a protein. Occurs in the cytoplasm at ribosomes. Requires mRNA, ribosomes (rRNA & proteins), tRNA, Amino Acids, and energy.

21 tRNA structure: a strand of RNA ~80 nucleotides long with the 2 dimensional shape of a cloverleaf. One end has an anti-codon, which will bind to the codon of the mRNA. The other end has the amino acid, which corresponds to the codon sequence.

22 1. Initiation: The ribosome, mRNA, and the initiator tRNA with the first amino acid come together. The initiator tRNA binds to the start codon, which is AUG. This occurs at the P-site.

23 . Elongation: An incoming tRNA (carrying an amino acid) binds to the correct codon at the A-site. Then a peptide bond (a bond between amino acids) is formed.

24 Termination: Elongation continues until a stop codon is reached. They are UAA UAG and UGA, A release factor protein binds to the A-site and causes a chemical reaction to free the polypeptide chain from the ribosome.

25 Translation (animated) * Process takes place on a ribosome

26 Formation of Polypeptide Chain(Protein)= Translation

27 Termination of Translation: When the t-RNA anticodon reaches a stop codon on m-RNA


Download ppt "RNA A nucleic acid which acts as a messenger between DNA and the ribosomes to carry out the process of making proteins from amino acids. Structure is similar."

Similar presentations


Ads by Google