1/19/12Building Life- The Cell o The basic unit of lifeo Two kinds Somatic – compose all your body except Sex (or germ) Cells - Ova/eggs- Sperm For a trait to be significant, it must be carried in the sex cells- Egg and sperm join to form zygote- Zygote – replicates to form entire organism- Kingdoms of Animalso Monera Algae, bacteria No nucleus (Prokaryotes)o Protista - eukaryoteo Fungi – eukaryote (nucleus), sexual reproductiono Plants – eukaryote, sexual reproductiono Animals – eukaryote, sexual reproduction- DNA o Found in nucleus of eukaryoteso Chromosomes are made of DNAo Deoxyribonucleic Acido Can be thought of as 64 three-letter words Made up of nucleotides- Sugar + phosphate + one of four bases- Baseso Adenine (A)o Thiamine (T)o Cytosine (C)o Guanine (G) A always bonds to T C always bonds to Go Structure Ladder- Sides are made up of sugars and phosphates- Rungs are bases- Double helix form- AT/CG are held together with hydrogen (H) bondso Replication for Cell division Making a copy of DNA Enzyme breaks apart H bonds Bases attract partners (A:T/C:G) and creates copyo Protein Synthesis (The most important thing DNA does) DNA can’t leave nucleus mRNA - m = messenger- carries DNA info out of nucleus tRNA - t – transfer- carries amino acids with bases to make protein Ribosome - Helps produce proteins Two stages- Transcription o The cell gets a signal to make a proteino Only a portion of the strand of DNA has information for protein synthesiso The DNA unwinds and exposes the sectiono The RNA is attracted to it due to the attraction of the baseso RNA organizes code by means of this transcription- Translation o Triplet – 3 letters of DNAo Codon – 3 letters of mRNAo Anticodon – 3 letters of tRNAo mRNA moves outside nucleus and brings information to the ribosomeo ribosome interprets codons and tRNA brings anticodon matcheswith amino acidso Amino acids form together to make a protein or a part of a proteino The ribosome provides energy to bond the amino acids together There are 64 possible combinations of the letters, resulting in 20 words with
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