DNA, RNA, and Protein Synthesis
DNA review What are the components of a nucleotide: 1. a deoxyribose sugar 2. a phosphate group 3. one of the four nitrogenous base What nitrogenous bases pair together in DNA: Adenine with Thymine Cytosine with Guanine
The sequence of bases in DNA forms the Genetic Code A group of three bases (a triplet) controls the production of a particular amino acid in the cytoplasm of the cell. The different amino acids and the order in which they are joined up determines the sort of protein being produced.
A sequence of triplets in the DNA molecule may code for a complete protein. Such a sequence forms a gene. Gene: a sequence of nucleotide bases that codes for a protein and thus determines a trait. There may be a thousand or more bases in one gene.
Proteins Proteins are Hormones Enzymes Antibodies Proteins are used for Repair and Maintenance Energy Proteins are made up of amino acids linked together by peptide bonds. The long chain of amino acids are called polypeptides.
DNA is found inside the nucleus of eukaryotes Proteins, however, are made in the cytoplasm of cells by the ribosomes Ribosomes may be free-floating or attached to the surface of rough ER
Protein Synthesis- How the genetic code in the nucleus (contained in DNA) gets to the ribosome (to build a protein) https://www.youtube.com/watch?v=gG7uCskUOrA
LiveSlide Site https://www.youtube.com/watch?v=gG7uCskUOrA
DNA versus RNA DNA stands for Deoxyribonucleic Acid DNA is double stranded DNA contains the sugar deoxyribose DNA is the master plan in code RNA stands for Ribonucleic Acid RNA is single stranded RNA has the sugar ribose RNA is the transcription of that code
DNA versus RNA DNA contains thymine RNA contains uracil
Three Types of RNA Messenger RNA (mRNA): copies DNA’s code and carries the genetic information to the ribosomes Ribosomal RNA (rRNA): along with proteins, makes up the ribosomes Transfer RNA (tRNA): transfers amino acids to the ribosomes to help synthesize proteins
From DNA to a protein The sequences of bases in DNA code for various genes. Cells use the DNA code to build (synthesize) proteins. This process includes 2 steps: 1. Transcription 2. Translation
Transcription Within the nucleus, DNA is transcribed (copied) into messenger RNA (mRNA) Given the following DNA code, write out the complimentary RNA strand: A U C G T A G C
Transcription
Translation Transfer RNA (tRNA) brings the matching amino acids to build the protein *proteins are made up of amino acids linked by peptide bonds mRNA then travels to the ribosome, made up of rRNA and proteins, where the genetic code is translated.
Translation
Translation
https://www.youtube.com/watch?v=T5gEIViVAPw
Determining amino acid sequence Start in the middle and move out. Examples: AAG The genetic code shows the amino acid to which each of the 64 possible codons corresponds. To decode a codon, start at the middle of the circle and move outward. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Start in the middle and move out. Examples: AAG UCA The genetic code shows the amino acid to which each of the 64 possible codons corresponds. To decode a codon, start at the middle of the circle and move outward. Copyright Pearson Prentice Hall
Examples: GCA
Examples: GCA CAG