DNA, RNA, Protein Synthesis DNA Structure DNA Replication : DNA  DNA RNA Structure Protein Synthesis Transcription : DNA RNA Translation : mRNA  amino acid

Human Genotype The human genotype contains 46 chromosomes Each chromosome has 2 chromatid legs Each chromatid leg has thousands of genes Each gene has thousands of DNA nucleotides in loose strands called chromatin

Role of DNA 1) DNA stores the genetic information in the nucleus until is time to pass the genetic information on to progeny 2) DNA is the blueprint for the cell to make proteins

DNA Structure DNA is a double helix = twisted ladder DNA is a polymer of DNA monomers Eg. DNA nucleotides in a DNA strand are like beads in a necklace

DNA Nucleotide Each nucleotide has 3 sub-components 1) 5 carbon sugar called deoxyribose 2) phosphate group 3) nitrogen-containing base

DNA Nucleotide Base There are four bases: adenine (A), thymine (T), guanine (G) and cytosine (C) The name of the DNA nucleotide is the name of the base The DNA nucleotides undergo “complementary” base-pairing: A=T , T=A, G=C, C=G

DNA Nucleotides Hydrogen bonding between complementary bases : A=T T=A G=C C=G Keeps the two DNA strands together in the double helix shape

DNA Replication DNA Replication = 1 “Parent” Double Strand DNA  2 “Progeny” Double Strand DNA DNA Replication is called “Semi-conservative” because each progeny double strand DNA has one original parent DNA strand and one new DNA strand

DNA Replication DNA replication requires 3 enzymes: DNA helicase : “unzips” the double helix by breaking hydrogen bonds between bases DNA polymerase : attaches new DNA nucleotide to complementary DNA nucleotide in parent DNA strand DNA ligase: ties the strands back together

RNA Structure DNA Double helix Deoxyribose sugar A=T, T=A, G=C, C=G DNA remains in nucleus RNA Single strand Ribose sugar Uracil base replaces Thymine base A=U, T=A, G=C, C=G RNA is made in nucleus and moved to cytoplasm

Role of RNA Messenger RNA : carries protein synthesis information stored in DNA in the nucleus to the ribosome in the cytoplasm Transfer RNA: brings amino acids to the ribosome for protein synthesis Ribosomal RNA: combines with proteins to make the ribosomes