Lecture 4 Food Biotechnology PDF

Biotechnological Applications In Food Industry Dr. Eman Owis Lecturer Of Microbial Biotechnology – Mansoura Uni P h. D. G ö t t i n g e n U n i - G e r m a n y [email protected]  Food b...

Biotechnological Applications In Food Industry Dr. Eman Owis Lecturer Of Microbial Biotechnology – Mansoura Uni P h. D. G ö t t i n g e n U n i - G e r m a n y [email protected]  Food biotechnology Nanotechnology in Microorganisms Fermentation Genetically Modified Enzymes in food Introduction agriculture and food associated with food Biotechnology Food industry industry & Bioethics Bacteria, yeast and Applications of Definition Introduction Genetic Engineering Introduction molds nanotechnology Production of food Ethical aspects of food Branches of Factors influencing Fermenter DNA, RNA, Peotein enzymes from and agricultural biotechnology microbial activity microorganisms biotechnology Benefits of Importance of Molecular Biology Different enzymes in Types of bacteria in the food biotechnology industry fermentation techniques food industry Food biotechnology Importance of yeasts safety and regulations in foods Different techniques associated with food biotechnology  Products From Genetically Engineered Microorganisms How Do Genes Work? Microbial genetics Molecular biology Recombinant DNA technology  Terminology Molecular biology The study of biology on a molecular level including the structure, function, and makeup of biologically important molecules such as DNA, RNA, and proteins Recombinant DNA technology a set of techniques for manipulating DNA, including the identification and cloning of genes; the study of the expression of cloned genes; and the production of large quantities of the gene product Genetic engineering the process of transferring DNA from one organism into another that results in a genetic modification Components involved in molecular biology Protein RNA DNA Gene : Unit of heredity The DNA segments that carry genetic information are called genes. It is normally a stretch of DNA that codes for a type of protein or for an RNA chain that has a function in the organism. Genes hold the information to build and maintain an organism's cells and pass genetic traits to offspring.  Deoxyribonucleic acid (DNA) DNA is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. DNA is a set of blueprints needed to construct other components of cells , such as proteins and RNA molecules.  Two long strands make the shape of a double helix. two strands run in opposite directions to each other and are therefore anti-parallel. Chemically, DNA consists of two long polymers of simple units called nucleotides, with backbones made of base , sugars and phosphate groups.  Sugar +Base = nucleoside Phosphate+ sugar + Base = nucleotide  DNA Basics Quiz 1. What is DNA? 2. The first people to make a model of DNA were ________ & ______. 3. A strand of DNA is made up of repeating units of __________. 4. A nucleotide is composed of 3 parts, name all three. 5. List the 4 different nitrogenous bases. 6. Which part of the nucleotide makes up the backbone of the strand of DNA? 7. Out of Adenine, Guanine, Cytosine & Thymine, tell me the two complementary pairs.  Ribonucleic acid (RNA) RNA is a biologically important type of molecule that consists of a long chain of nucleotide units. Each nucleotide consists of a nitrogenous base, ribose sugar, and phosphate.  Difference between RNA & DNA RNA DNA RNA nucleotides contain DNA contains deoxyribose ribose sugar RNA has the base uracil DNA has the base thymine presence of a hydroxyl group Lacks of a hydroxyl group at the 2' at the 2' position of the ribose position of the ribose sugar. sugar. RNA is usually single-stranded DNA is usually double-stranded Difference between DNA and RNA  All RNA types are translated to protein. This statement is not correct. Why? Because rRNA, mRNA, and tRNA are not translated to proteins. Why? They are folded once produced and their folding did not allow their assembly in ribosomes for protein synthesis. They have functions in the cell. Messenger RNA (mRNA) mRNA carries information about a protein sequence to the ribosomes , the protein synthesis factories in the cell. It is coded so that every three nucleotides (a codon) correspond to one amino acid. In eukaryotic cells, once precursor mRNA (pre-mRNA) has been transcribed from DNA, it is processed to mature mRNA. This removes its introns —non-coding sections of the pre- mRNA.  Transfer RNA (tRNA) Transfer RNA (tRNA) is a small RNA chain of about 80 nucleotides that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. It has sites for amino acid attachment and an anticodon region for codon recognition that site binds to a specific sequence on the messenger RNA chain through hydrogen bonding.  Ribosomal RNA Ribosomal RNA (rRNA) is the catalytic component of the ribosomes. Eukaryotic ribosomes contain four different rRNA molecules: 18S, 5.8S, 28S and 5S rRNA. rRNA molecules are synthesized in the nucleolus. In the cytoplasm, ribosomal RNA and protein combine to form a nucleoprotein called a ribosome. The ribosome binds mRNA and carries out protein synthesis. Several ribosomes may be attached to a single mRNA at any time. rRNA is extremely abundant and makes up 80% of the 10 mg/ml RNA found in a typical eukaryotic cytoplasm.  RNA Quiz 1. Protein synthesis results in the creation of ________. 2. RNA has _______ strands. 3. RNA has the sugar _________. 4. Name the 4 bases for RNA. 5. RNA is usually ______ than DNA. 6. Name the 3 types of RNA. 7. What does mRNA do? 8. What does tRNA do? 9. rRNA is found on what cell part? 10.What are the base-pairing rules for RNA? Protein Proteins (also known as polypeptides) are made of amino acids arranged in a linear chain and folded into a globular form. The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded in the genetic code. The genetic code specifies 20 standard amino acids. Amino acids Amino acids are the monomers that make up proteins. Specifically, a protein is made up of one or more linear chains of amino acids, each of which is called a polypeptide. There are 20 types of amino acids commonly found in proteins in addition to selenocysteine “The 21 amino acid added recently”. Amino acids share a basic structure, which consists of a central carbon atom, also known as the alpha (α) carbon, bonded to an amino group NH 2​ a carboxyl group COOH, and a hydrogen atom. Peptide bond formation Genetic code Basic players in molecular biology: DNA, RNA, and proteins. Central dogma The central dogma of molecular biology is a theory stating that genetic information flows only in one direction, from DNA to RNA, to protein, or RNA directly to protein. This states that once 'information' has passed into protein it cannot get out again. In more detail, the transfer of information from nucleic acid to nucleic acid, or from nucleic acid to protein may be possible, but transfer from protein to protein, or from protein to nucleic acid is impossible. Information means here the precise determination of sequence, either of bases in the nucleic acid or of amino acid residues in the protein. Transcription Transcription is the process of creating an equivalent RNA copy of a sequence of DNA. Transcription is the first step leading to gene expression. During transcription, a DNA sequence is read by RNA polymerase , which produces a complementary, antiparallel RNA strand. Transcription results in an RNA complement that includes uracil (U) instead of thymine (T). Transcription process The stretch of DNA transcribed into an RNA molecule is called a transcription unit and encodes at least one gene. If the gene transcribed encodes for a protein , the result of transcription is messenger RNA (mRNA). This mRNA will be used to create that protein via the process of translation. Alternatively, the transcribed gene may encode for either rRNA or tRNA, other components of the protein-assembly process, or other A DNA transcription unit encodes for a protein (the coding sequence) and regulatory sequences that direct and regulate the synthesis of that  Transcription The rewriting of genetic instructions from DNA into RNA “transcribes” DNA into genes Takes place in the nucleus of eukaryotic cells Takes place in the cytoplasm of prokaryotic cells  Transcription Steps 1. Unwinding & separating the DNA strands  The enzyme RNA polymerase binds to a promoter (a specific codon that starts transcription) on the DNA molecule  DNA unwinds & separates Transcription Steps: Unwinding & Separating DNA File:RNA polymerase (1i6h).png  Transcription Steps 2. Adding RNA nucleotides to create a strand of RNA  RNA polymerase adds free-floating RNA nucleotides to one of the exposed DNA strands  The nucleotides that are added are complementary to one of the DNA strands  Only a specific section of the DNA strand is used to create the strand of RNA Adding RNA Nucleotides  Transcription Steps 3. Release of the RNA molecule  RNA polymerase reaches a termination signal that tells it to stop  RNA polymerase releases both the DNA & the newly formed RNA molecule  RNA created is mRNA  The RNA molecule is free to perform its “job”  RNA polymerase is available to transcribe more genes Releasing both DNA & RNA  Transcription Quiz 1. Transcription rewrites what? 2. Where does transcription take place in eukaryotic cells? 3. What is the 1st step in transcription? 4. What is the enzyme that unwinds & separates DNA? 5. What is the second step of transcription? 6. What are added to the exposed strand of DNA? 7. What tells RNA polymerase when to stop adding nucleotides? 8. The newly formed RNA is __RNA.  Transcription Quiz 9. When RNA polymerase reaches the terminal signal it releases both _______ & _______. 10.What does RNA polymerase do after it releases the DNA & newly formed RNA molecule? Translation Translation is the first stage of protein biosynthesis. In translation, (mRNA) produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or polypeptide , that will later fold into an active protein. Translation occurs in the cell's cytoplasm , where the large and small subunits of the ribosome are located and bind to the mRNA. Translation process The ribosome facilitates decoding by inducing the binding of tRNAs with complementary anticodon sequences to mRNA. The tRNAs carry specific amino acids that are chained together into a polypeptide as the mRNA passes through and is "read" by the ribosome. the entire ribosome/mRNA complex will bind to the outer membrane of the rough endoplasmic reticulum and release the nascent protein polypeptide inside for later vesicle transport and secretion outside of the cell.  Translation Is the synthesis or making of a protein The instructions for making a protein are transcripted from DNA into mRNA All three types of RNA are involved in translation  Translation Steps 1. Joining RNAs – rRNAs & tRNAs attach to a mRNA – Enzymes attach an amino acid to one end of each tRNA – The other end of the tRNA contains the anticodon for mRNA – A tRNA carrying the amino acid methionine must be present to start the reading of mRNA & attaches to a start codon on mRNA T-RNA Translation  Translation Steps 2. Creation of a polypeptide chain  tRNAs carrying correct amino acids, pair their anticodons w/ the codons on the mRNA strand  Methionine detaches from the 1st tRNA after the 2nd anticodon is added  A peptide bond forms b/t methionine & the 2nd amino acid to start a polypeptide chain  The 1st tRNA exits the ribosome  Ribosome moves one codon down on the mRNA strand Translation  Translation Steps 3. Polypeptide Chains Grow  mRNA continues to move through the ribosome  New tRNAs w/ correct anticodons move in & peptide bonds are created b/t the amino acids of each tRNA  The polypeptide chain moves from one tRNA to the next tRNA & attaches to its amino acid File:Ribosome mRNA translation en.svg Translation  Translation Steps 4. Stop Codon – Polypeptide grows one amino acid at a time until it reaches a stop codon – Polypeptide falls off Translation  Translation Steps 5. End of Translation  All the parts that are needed for translation come apart  The last tRNA exits the ribosome  The ribosome moves away from the mRNA  All the parts are free to be used over & over again Translation  Translation Quiz 1. Proteins are made of ____ ____, which are made of 3 RNA ______. 2. Polypeptides are chains of amino acids linked by _____ ____. 3. Translation is the synthesis of ________. 4. List the types of RNA involved in protein synthesis.  Translation Quiz Cont’d 8. The polypeptide chain stops growing when it reaches the ______ ________. 9. When the polypeptide chain reaches the stop codon what happens to the chain? 10.Once the polypeptide chain falls off, what happens to all the parts that assembled to translate RNA?  Post-translational modifications After translation, some proteins are subjected to modification in order to suit the function. Covalent addition of functional groups, proteolytic cleavage of regulatory subunits, phosphorylation, glycosylation, and lipidation are examples of such processes. The E. coli system is a rapid method for expressing proteins but lacks many of the posttranslational modifications found in eukaryotes. In contrast to E. coli, the eukaryotic P. pastoris, baculovirus/insect cell, and mammalian systems promote good protein folding and many posttranslational modifications.  Plasmid Vector Vector is a plasmid or manipulated artificially after ligation and digestion reaction series, whereas a plasmid naturally occurs in bacterial cells. There are several vectors, which can be used in recombinant DNA, whereas all plasmids may not be used directly in recombinant DNA technology.