From DNA to Protein (11.2)
What is a Protein? Complex, 3-dimensional structures made from chains of amino acids Regulate cell functions Produced at the ribosomes Ex: Blood contains red blood cells (RBC) that transport oxygen to different parts of our bodies. RBC’s use a protein called “hemoglobin” to capture and carry the oxygen. If the instructions (DNA) are changed or “mutated” changes in the hemoglobin protein could result. The RBCwould no longer be able to carry oxygen (Sickle Cell Anemia).
Sickle Cell Anemia Each sickle cell will reproduce a new sickle cell. More common in african americans
How are proteins made? Nucleic acid- stores cellular information in cells in form of a code
Protein Synthesis RNA (Ribose Nucleic Acid) How does RNA differ from DNA? Single stranded (half-zipper) The sugar in RNA is ribose (DNA has deoxyribose) Instead of Thymine (T), RNA contains Uracil (U) in RNA Adenine (A) pairs with Uracil (U)
3 types of RNA Messenger RNA (mRNA) -Brings instructions from DNA in the nucleus to the cytoplasm Ribosomal RNA (rRNA) -binds to the mRNA and uses instructions to assemble the amino acids in the correct order Transfer RNA (tRNA) -Supplier. Delivers amino acids to the ribosome to be assembled into a protein. (amino acid delivery truck) Cant bring book out of library. Make copies of pages you need. Leave library
Transcription (DNA mRNA) Enzyme unzips DNA molecule Free RNA nucleotides form with complementary base pair (GC and AU) New mRNA strand leaves nucleus and enters the cytoplasm (finds ribosome) http://www.stolaf.edu/people/giannini/flashani mat/molgenetics/transcription.swf
DNA replication vs. Transcription Double stranded DNA Purpose? Single stranded RNA Purpose? DNA replication Purpose- Double number of chromosomes for mitosis Transcription purpose- bring message to the ribosome to make protein
Genetic Code 3 nitrogenous bases of mRNA code for one Amino Acid Each group is known as a codon Ex: The codon GCU results in the amino acid Alanine 64 combinations are possible when using a sequence of 3 nitrogenous bases Universal Code for all organisms
Genetic Code “Alphabet”
Amino Acids (Serine, Leucine, etc) Proteins Chains of amino acids Amino Acids (Serine, Leucine, etc) Codons (3 nucleotides -UCA, CUA, etc) Nucleotide Nitrogenous Base This slide might be confusing. Still working on it
Translation (mRNA protein) p.294 Occurs in the cytoplasm at the ribosomes mRNA attaches to ribosome. tRNA (carrying a specific AA) approaches ribosome tRNA (anticodon) attaches with mRNA (codon) A new tRNA molecule attaches next to previous tRNA molecule and AA from each tRNA bond together (peptide bond) Ribosome slides down mRNA molecule to allow a new tRNA to attach. Old tRNA molecules are released. A long chain of AA is formedprotein!! Como say llama Whats ur name
Protein Synthesis Animation Do it yourself When we eat a steak and all that protein what is the difference b/w the protein we eat and the protein we make? Protein we eat is broken up into AA that our cells use to make more protein