Download Organic Molecules Proteins: The Workhorses of Life Carbohydrates

Organic Molecules
Proteins: The Workhorses of Life
Carbohydrates
Lipids
Minerals and Vitamins
Great Idea:
A cell s major parts are constructed from a few simple
molecular building blocks
Organic Molecules Four Basic Characteristics
•  Most molecules based on chemistry of
carbon
–  Organic molecules
•  Life s molecules form from few
elements
–  H, O, C, N à 97.5% of body weight
•  Molecules composed of simple building
blocks
–  Arranged differently
•  Shape determines behavior
–  Determines ability for bonding
Atoms in the Human Body
Chemical Shorthand •  No H atoms or bonds to H are shown •  C atoms are not shown explicitly Shorthand
Proteins: The Workhorses of Life Proteins:
The Workhorses of Life
Amino Acids:
Building Blocks of Proteins
•  Amino acid
–  Carboxyl group
–  Amino group
–  Carbon atom
–  Side group
•  Side group
–  Makes amino acid unique
Amino Acid Structure
Distinctive Side Chain on
Amino Acids
Proteins
•  Protein –  Large molecule –  Chain of amino acids •  Only 20 amino acids in living organisms Science by the Numbers
•  How many proteins can you make?
Proteins as Enzymes •  Enzymes –  Specific shape and structure –  Facilitates bonding –  Recycled An Enzyme in Action
Computer-­‐Generated Image of an Enzyme in AcOon The Science of Life
•  Proteins and diet –  EssenOal amino acids –  High-­‐quality proteins –  Low-­‐quality proteins Essential Amino Acids in
Eggs and Cornmeal
How Drugs Work
•  Blocking enzymes
–  Block active site
–  Molecules cannot bond
–  Reaction does not take place
•  Shape of molecules
–  Block membrane transport
–  Block neurotransmitters
Carbohydrates
Structure
C, H, O
Simplest - sugars
CnH2nOn
Monosaccharides
Polysaccharides
Starches
Cellulose
Glucose Fructose Polysaccharides Lipids
•  Lipids –  Insoluble in water •  Role of lipids –  Cell membranes –  Store energy •  Phospholipids –  Make up cell membrane Structure of a Phospholipid Saturated vs. Unsaturated Lipids Cell Membranes •  Cell membrane –  Hydrophilic –  Hydrophobic Lipid Bilayer Minerals and Vitamins
Vitamin and Mineral Supplements Minerals •  Minerals –  All chemical elements except C, H, N, O •  Example –  Calcium •  2% of weight RDAs for Minerals Vitamins •  Vitamins –  Organic molecules –  Must be taken in with food •  Except vitamin D •  FuncOon –  Assist enzymes Types of Vitamins •  Water soluble –  Vitamins B & C •  Fat soluble –  Vitamins A, D, E, & K Citrus Fruit and Vitamin C RDAs for Vitamins Classical and
Modern Genetics
Chapter 23
Great Idea:
All living things use the same genetic code to guide
the chemical reactions in every cell.
Chapter Outline
•  DNA and the Birth of Molecular
Genetics
•  The Genetic Code
DNA and the Birth of
Molecular Genetics
Nucleotides: The Building
Blocks of Nucleic Acids
•  Nucleotide
–  Three molecules
•  Sugar
–  DNA: deoxyribose
–  RNA: ribose
•  Phosphate ion
•  Base
–  Adenine (A)
–  Guanine (G)
–  Cytosine (C)
–  Thymine (T); uracil (U) in RNA
Ribose and Deoxyribose
Nucleotide
DNA Structure
•  Bonding pattern
–  Adenine:Thymine
–  Cytosine:Guanine
AT
TA
CG
GC
DNA Structure
RNA Structure
•  Differences
–  One string of nucleotides
–  Sugar is ribose
–  Thymine replaced by uracil
•  Uracil (U) bonds with adenine
The Replication of DNA
•  DNA replication
–  Occurs before mitosis and meiosis
•  Process
–  DNA double helix splits
–  New bases bond to exposed bases
–  Result
•  Two double-stranded DNA molecules, each
identical to the original molecule
DNA ReplicaOon The Genetic Code
Transcription of DNA
•  Transcription
–  Information transport
–  Uses RNA
•  Process
–  Unzip DNA
–  RNA binds to exposed bases
–  RNA moves out of nucleus (mRNA)
TranscripOon of DNA tRNA •  tRNA
–  Reads message
–  Structure
•  Amino acid
•  3 bases
The Synthesis of Proteins •  Process
–  mRNA moves to ribosome
–  rRNA aligns mRNA and tRNA
–  tRNA matches codon on mRNA
–  Amino acid chain forms
•  Basis for protein
Computer-­‐Generated Model of tRNA The InteracOon of mRNA and tRNA The FormaOon of a Protein The GeneOc Code Protein Synthesis -­‐ cont. •  One gene codes for one protein
•  Protein drives chemical process in
cell
•  DNA
–  Introns
–  Exons
•  All living things on Earth use the same
genetic code
Protein ProducOon from DNA Mutations and DNA Repair
•  Mutations
–  Change in DNA of parent
–  Causes
•  Nuclear radiation
•  X-rays
•  UV light
•  DNA repair
–  10,000 hits per day
–  Cells repair damage
Why Are Genes Expressed? •  Gene control
–  Turning genes on and off
–  Each cell contains same genes
–  Not all cells have same function
–  Certain genes activated
•  Scientists currently studying how
Viruses •  Virus
–  Not alive
–  No metabolism
–  Cannot reproduce on own
•  Structure
–  Short DNA or RNA
–  Protein coating
Viruses – cont. •  How it works
–  Taken into cell
–  Takes over cell
–  Produces more copies
–  Kills cell
Bacterial Virus Herpes Virus HIV •  Human Immunodeficiency Virus (HIV)
–  Contains RNA
–  Codes back to DNA
–  DNA incorporated into cell
–  Makes new viruses
–  Cell dies
•  Complex
–  Two protein coats
•  Outer coat fits T cell receptors
•  Inner coat encloses RNA
HIV Viral Epidemics •  Viruses
–  Cannot use medication
–  Use vaccination
•  Viruses evolve rapidly
–  HIV
–  Influenza
–  SARS
–  Bird flu
Role of Phagocytes The Human Genome •  Human Genome Project
–  DNA sequencing
–  3 billion bases
Wooly Mammoth DNA, Genes, Chromosomes, and Genomes Technology •  New ways to sequence
–  J. Craig Venter
•  Faster sequencing
Thinking More about Genetics
•  The ethics of genes
–  What should we do with genetic
information?
–  Patent it?
–  Share with insurance companies?
–  Change it? Genetic engineering….
Great Idea:
Our new understanding of genetic mechanisms is leading to
enormous technological advances in medicine and other
aspects of our lives.
Chapter Outline •  The Technology of Genes •  Stem Cells, Cloning, and RegeneraOve Medicine •  The New Face of Medicine •  Unraveling the Past: Mitochondrial DNA The Technology of Genes GeneOc Engineering •  GeneOc engineering –  Foreign genes inserted –  ExisOng genes altered •  Technique –  RestricOon enzymes cut DNA –  Another DNA strand binds –  New gene is expressed GeneOc Engineering – cont. •  Examples –  Insulin –  Agriculture •  GMO –  DOA –  FDA –  EPA •  Bioterrorism RestricOon Enzymes The Process of GeneOc Engineering GeneOcally Modified Organisms Technology •  Bioterrorism –  Anthrax •  Spores –  Smallpox –  Spanish influenza – 1918 –  Department of Homeland Security Technology •  The PCR process Science by the Numbers •  PCR mulOplicaOon –  Each cycle doubles the number of DNA molecules DNA FingerprinOng •  DNA fingerprinOng –  Analysis of DNA in human Ossue –  Uses •  IdenOfy criminals •  IdenOfy vicOms •  Process –  Analyze DNA secOons for repeats –  Compare to individual of interest •  VNTR •  STR CSI STR Method of DNA FingerprinOng Stem Cells, Cloning, and RegeneraOve Medicine Stem Cells, Cloning, and RegeneraOve Medicine •  Gene Control –  Genes on or off –  Produce only copies •  Early development –  Pluripotent •  Develop into any cell in body Stem Cells, Cloning, and RegeneraOve Medicine – cont. •  Development –  Blastocyst •  Outer cells: placenta •  Inner cells: embryonic stem cells –  Gastrula •  Not pluripotent •  DifferenOaOon –  Adulthood •  SomaOc or adult stem cells •  Stem cell line –  Reproduce without differenOaOon Early Stages of Embryonic Development Science in the Making •  Cloning Dolly the sheep –  1997; Ian Wilmut –  ReproducOve cloning •  Procedure –  Other mammals cloned The First Cloned Mammal Foreign DNA Introduced into an Animal Cell The New Face of Medicine Cancer-­‐A Different Kind of GeneOc Disease •  Normal Cell –  Guardianship •  Cancer –  Cells reproduce without restraint •  Due to geneOc defect •  Usually 5–6 damaged genes –  CollecOon of diseases Cancer-­‐A Different Kind of GeneOc Disease – cont. •  GeneOc defects –  Increase cancer probability –  LifeOme risk >80% •  Cure –  Surgery, radiaOon, chemotherapy –  Gene therapy Normal and Cancer Cells DNA Repair in a Cell Plants and PesOcides Unraveling the Past: Mitochondrial DNA Unraveling the Past: Mitochondrial DNA •  Mitochondria –  Independent DNA (mtDNA) –  Single loop –  37 genes –  Non-­‐coding secOon •  1000 base pairs •  Use to study human evoluOon –  All mitochondria from mother DNA in Mitochondria Thinking More about Embryonic Stem Cells •  Issue debated •  No simple answers