Cell Controls How does a cell control its processes?

DNA – deoxyribonucleic acid Unit of heredity Blueprint for proteins (instructions) Found in chromosomes in the nucleus of every cell

DNA Watson and Crick – proposed double helix shape of molecule (twisted ladder)

DNA Structure Monomer – nucleotide 1.Sugar (Deoxyribose) 2.Nitrogen Base 3.Phosphate biology.clc.uc.edu/graphics/bio104/nucleotide.jpg

DNA Structure Polymer – nucleic acid Backbone made of sugar and phosphate chain Steps of ladder are nitrogen bases mages/ch1_nucleotide.jpg

DNA Structure Four possible nitrogen bases in DNA Adenine Thymine Cytosine Guanine Base pair rules users.rcn.com/.../BiologyPages/B/BasePairing.gif

DNA Structure Video f0&feature=player_embedded f0&feature=player_embedded

DNA Model Lab Purpose: create a model of a DNA molecule 1.Separate gumdrops into color groups. 2.Designate a color for each component of the model, list in lab notebook. 3.Build a double helix model using toothpicks for bonds. 4.Use p. 284 in the text for a guide.

DNA Model Activity Questions Draw your model in your lab notebook. Answer: 1.In your model, are the sugar molecules directly across from each other? 2.Are the phosphates molecules directly across from each other? 3.What makes up the backbone? 4.How many adenine – thymine rungs did you make? 5.How many cytosine – guanine rungs did you make? 6.Is the arrangement of the bases of your ladder the same as others in the class? Why or why not?

DNA Replication Makes an exact copy of DNA molecule Occurs in nucleus before cell division Each cell will have its own set of instructions

DNA Replication Steps 1.Original DNA strand unzipped by enzymes, base pairs separate /DNA_replication_split.svg/297px- DNA_replication_split.svg.png&imgrefurl= plit.svg&usg=__8ipMfzUIe3bIB_V2tVy2tUoCmj0=&h=599&w=297&sz=74&hl=en&start=7&um=1&tbnid=g 8l_98FU03rvEM:&tbnh=135&tbnw=67&prev=/images%3Fq%3DDNA%2Breplication%26um%3D1%26hl%3 Den%26rls%3Dcom.microsoft:en-us%26sa%3DN

DNA Replication Steps 2. Free nucleotides base pair with open bases

DNA Replication Steps 3. Results in two identical copies of DNA molecule

DNA Replication Semi-conservative replication: each new strand has one backbone of the original strand A/semiconservative%20replication.jpg

DNA Replication Practice Original DNA Strand New DNA Strands

DNA Replication Video Clips S0&feature=player_embedded S0&feature=player_embedded tus&feature=player_embedded tus&feature=player_embedded rg&feature=player_embedded rg&feature=player_embedded

RNA – ribonucleic acid Works to make proteins Ribose sugar in backbone Single stranded Base pairs: – Guanine, Cytosine – Adenine, Uracil – (No thymine in RNA)

Three types of RNA 1. Messenger RNA (mRNA) Found in nucleus and at ribosomes Forms codons – 3 base sequence Does transcription – copies DNA code in nucleus, moves to ribosome Cell Nucleus

mRNA video

Three types of RNA 2. Ribosomal RNA (rRNA) Makes up ribosomes Reads mRNA codons and helps assemble amino acids in correct order

Three types of RNA 3. Transfer RNA (tRNA) Found in cytoplasm Transports amino acids to ribosomes and assembles them into a protein (translation)

Three types of RNA 3. Transfer RNA (tRNA) Brings amino acid to ribosome Anticodon pairs with mRNA codon at the ribosome Amino acid Anti-codon

Types of RNA video

Compare DNA and RNA Deoxyribonucleic acid Holds the code for making proteins “The Boss” Found in the nucleus of cells Double helix – 2 strands Made of nucleotides Backbone Deoxyribose sugar Phosphate Nitrogen Bases Adenine Thymine Cytosine Guanine Ribonucleic Acid Copies the codes and helps make the proteins “The Workers” Found in nucleus and cytoplasm 3 types Messenger – mRNA Ribosomal – rRNA Transfer – tRNA Single strand Made of nucleotides Backbone Ribose sugar Phosphate Nitrogen Bases Adenine Uracil Cytosine Guanine

DNA Rap O8 O8

Biology Central Dogma DNA  RNA  Protein Transcription Translation

How are proteins made in a cell? Transcription: – Occurs in nucleus when a protein is needed – DNA  mRNA nucleus

Steps of transcription 1.DNA unzips 2.Free mRNA nucleotides join the open DNA bases 3.mRNA leaves DNA, DNA rezips 4.mRNA segment leaves nucleus, moves to ribosome

Steps of transcription Code is copied (transcribed) from DNA instructions DNA = T A C C G A T T G mRNA = A U G G C U A A C mRNA codon = 3 bases, codes for 1 amino acid

RNA Transcription Practice DNA strand: ATCCGGAATCCGTACGCTCTATAA RNA strand: ____________________________ What is this process called? Where does this process occur? Where will mRNA go after being made? What is the 3 base code on mRNA called? What does it code for?

Biology Central Dogma DNA  RNA  Protein Transcription Translation

mRNA code is translated into a protein Occurs at ribosome mRNA codon = amino acid How do we know what codon codes for which amino acid?

Amino Acid Chart

Steps of translation 1.mRNA attaches to ribosome 2.rRNA reads codons 3.tRNA brings in amino acid 4.tRNA anticodon matches mRNA codon 5.amino acids joined by peptide bonds to form a protein

Easter Eggs and Proteins 1.Find ONE egg 2.Copy the DNA code from your egg 3.Transcribe it into mRNA codons 4.Determine the anticodon sequence for each message 5.Search out the correct anticodon card and copy the word on back in lab notebook 6.Write the sentence from the revealed words

Protein Synthesis Practice DNA: TACCGCTATCCCGAATAATAGAAT Copy this table and complete. Answer questions. DNAProcess  mRNAProcess  Amino Acid tRNA TAC

Protein Synthesis Practice Where is DNA in the cell? Where are amino acids assembled? Where is the codon found? What is it used for? Where is the anticodon found? What is it used for? Did you build a protein? Why?