Presentation is loading. Please wait.

Presentation is loading. Please wait.

From gene to protein. DNA:nucleotides are the monomers Proteins: amino acids are the monomers DNA:in the nucleus Proteins:synthesized in cytoplasm.

Similar presentations


Presentation on theme: "From gene to protein. DNA:nucleotides are the monomers Proteins: amino acids are the monomers DNA:in the nucleus Proteins:synthesized in cytoplasm."— Presentation transcript:

1 From gene to protein

2 DNA:nucleotides are the monomers Proteins: amino acids are the monomers DNA:in the nucleus Proteins:synthesized in cytoplasm

3 DNA -mRNA-Protein = gene expression -central dogma of biology -a section of DNA's code (a gene) is copied (transcribed) onto mRNA. -mRNA carries the code to the ribosome where the code is translated, with the help of tRNA, into a sequence of amino acids (polypeptide)

4 -three bases on DNA = triplet -code for three bases on mRNA = codon -codes for one amino acid

5 - occurs in nucleus - purposes is to produce a copy of DNA called messenger RNA which carries genetic information to the cytoplasm.

6

7 -One strand of DNA acts as template - RNA polymerase binds to promoter region which includes the initiation site on a section of DNA (gene)

8 - RNA polymerase moves along the DNA strand unwinding and unzipping, separating the strands by breaking the hydrogen bonds. - the mRNA strand grows. It is complementary to the DNA template

9 - transcription continues until a termination site is reached -mRNA strand is released

10 Watch video clip: http://youtu.be/WsofH466lqk Complete questions in notes and go over

11 - triplet = 3 bases on DNA - codon= 3 bases on mRNA - codes for a specific amino acid. One of twenty possible amino acids. Redundancy built into system. 64 possible codons - universal code since it used by all organisms -stop and complete questions/ go over

12 - purpose is to translate info on mRNA into a chain of amino acids that fold into a functional protein. - one gene codes for one protein

13 - ribosomes have two subunits made up of protein and RNA - site of attachment of mRNA and tRNA -site of protein synthesis

14 - a folded strand of RNA with a site for amino acid to attach at one end. - the other end has three bases exposed which complement with an mRNA codon - called an anticodon

15

16 - initiation - elongation - termination

17 - mRNA attaches to small ribosomal subunit - start codon AUG - tRNA carrying amino acid methionine pairs with codon AUG (anticodon UAC on tRNA) - large ribosomal subunit sandwiches mRNA -2 codon sites on ribosome "P" & "A" - "P" site occupied, "A" site empty

18

19 - a second tRNA with an anticodon moves into the "P" site - covalent peptide bond forms between a.a of "A" site and a.a of "P" site. -"P" site tRNA breaks away to get another a.a - ribosomal complex shifts along mRNA to next codon. Process continues, polypeptide grows

20

21 - elongation continues until a "stop" codon is reached - UAA, UAG, UGA - release factor ( a special protein) binds to the A site. - the polypeptide is released and the ribosome separates into the large and small subunits

22 Protein synthesis Video http://youtu.be/5bLEDd-PSTQ Complete questions 1-3


Download ppt "From gene to protein. DNA:nucleotides are the monomers Proteins: amino acids are the monomers DNA:in the nucleus Proteins:synthesized in cytoplasm."

Similar presentations


Ads by Google