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Nucleic Acids, Proteins, & Gene Expression
Honors Biology ch 4 & 8
Macromoleculesin the
Biosphere
Macromolecules are large organic carbon compoundsCarbohydrates (Cell Energy)LipidsProteins Nucleic Acids
Life is built out of carbon molecules
Part 4: Proteins & Nucleic Acids
Prior to 1900’s human civilization understood:Cells preformed various functions for lifeProteins and nucleic acids existed
History of Nucleic Acids & Proteins
1941 Beadle and Tatum determined:Nucleic acids and proteins were linkedAnd responsible for many cell functions
History of Nucleic Acids & Proteins
Monomer: Nucleotide5-Carbon SugarPhosphate GroupNitrogen Base
Polymer: DNA/ RNA strands
Nucleic Acid Structure
Biological Functions:Storage of heritable informationHelps make protein
Nucleic Acid Function
Monomer: Amino AcidCarboxylic Acid (C & O)Amine Groups (N & H)
Polymer: Polypeptide Chain
3D Structure of ProteinComplex proteins fold
Protein Structure
Biological Functions:Catalyze chemical reactions (enzyme)Build & repair tissuesTransport & signal molecules
Protein Function
Human Tissues: Skin, Hair, Nails, Organs…Enzymes: make or break molecules
Biological Examples of Proteins
How are these molecules constructed in the biosphere
Building Proteins
DNA RNA Protein
Gene Expression
Part 5: Gene Expression
Organisms are a collection of traits!
Genes of life
Every cell of every organism has genetic information
Entire set of DNA for an individual organism
Genes of life
Molecular process of converting DNA genes into a trait
Gene Expression
Gene Expression Detailed Process
Stage 1: TranscriptionGene (section of DNA) is converted into mRNA
codeStage 2: Translation
mRNA, tRNA, rRNA link amino acids based on code
Stage 3: FoldingPolypeptide chain is folded into a specific
protein shape
Gene Expression Basic Process
http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/translation.swf
http://highered.mcgraw-hill.com/olc/dl/120077/micro06.swf
http://www.youtube.com/watch?v=41_Ne5mS2ls
Translation Animations
Enzymes
One chemical changes into another:Reactant: chemical that enters rxn.Product: chemical produced by the rxn.
Review: Chemical Reaction
Not all rxns. occur spontaneouslyActivation energy:
the energy required to start a reaction
Review: Chemical Reaction
Inside a cellChemical reactions occur all the timeThese reactions are normally slow
Biological Organisms
Biological CatalystsEnzymes
Speed up reactions by lower the activation energy
Complex 3D polypeptide chain (proteins)
Enzyme Structure
Enzymes interact with substratesMake molecules
Break molecules
Enzyme Function
Water breaks down eggsPEPSIN is an enzyme
What is the substrate in the experiment?Which test tube will break down the egg fastest?
Experiment
Lock and Key ModelEnzymes must fit perfectly with substrateTherefore, one enzyme per substrate
Enzyme Specificity
Induced Fit Model:The active site of an enzyme binds to a
substrateEnzyme changes shape to perform a biological
rxn.
Enzyme Specificity
Amylase:in your mouth breaks down starch
Peptidasein your stomach break down proteins
Lipase:in your small intestine break down lipids
There are over 2000 known enzymes in your body
Common Enzymes in your Body
1. Temperature: Increase in temp. increase in enzyme speedToo much heat, the enzyme is denatured or
destroyed
2. pH: Also denature the enzyme
What affects an enzymes?
Experimental Results
Experimental Results