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Chapter 15. Biochemistry. Energy of Life. Sun energy is converted to chemical energy by plants 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Building energy molecules = anabolism Breaking down molecules for energy = catabolism. Molecules of Life: Carbohydrates. Formed from C, H, and O
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Chapter 15 Biochemistry
Energy of Life • Sun energy is converted to chemical energy by plants 6CO2 + 6H2O C6H12O6 + 6O2 • Building energy molecules = anabolism • Breaking down molecules for energy = catabolism
Molecules of Life: Carbohydrates • Formed from C, H, and O • Types: • Sugars = monosaccharides • Names end in –ose • Starches = polysaccharide • Plant starch = amylose, large granules • Animal starch = glycogen, small granules • Cellulose = polysaccharide • Different linkages than starches
Molecules of Life: Fats • Called lipids • Types: • Fatty acids (triglycerides) • Steroids: cholesterol, sex hormones • Fat-soluble vitamins • Waxes • Classified by degree of saturation • Insoluble in water • Usually less dense than water
Molecules of life: Proteins • Vital: present in all body tissues • Combinations of amino acids • 9 are essential amino acids • All have 3-letter abbreviations • How many combinations can you make from threonine (Thr), proline (Pro), cysteine (Cys), and leucine (Leu)?
Molecules of life: Protein Structure • Primary • Amino acid sequence: long chain • Secondary • Pleated sheet • α- helix • Tertiary • 3-dimensional folding of chain • Quaternary • Multiple separate tertiary structures bonded together
Molecules of life: Protein Structure α-helix Pleated sheet Both due to hydrogen bonding!
Molecules of life: Protein Structure • Linking proteins together • Primary = peptide bonds (amide linkage) • Secondary • Hydrogen bonds • Tertiary, Quaternary • Ionic bonds (“salt bridge”) • Disulfide bond (covalent) • Dispersion forces • Most important for non-polar side-chains
Molecules of Life: Special Proteins • Enzymes • Catalyze reactions • Lower activation energy: bring reactants into precise proximity • Increase reaction rate • Lower necessary temperature • Not used up in reaction! • Some for catabolism, some for anabolism
Molecules of Life: Nucleic Acids • Nucleotides: • Sugar • Ribose (in RNA) • Deoxyribose (in DNA) • Phosphate • PO43- polyatomic ion bonded to sugar • Backbone of the DNA • Amine base • Purines: adenine (A), guanine (G) • Pyrimidines: cytosine (C), thymine (G), uracil (U) in RNA • Purines bond with pyrimidines • Linked by hydrogen bonding
Molecules of Life: Nucleic Acids • Double helical structure • DNA synthesis • Unzipped by enzymes for replication • “Semi-conservative replication” • Sets of nucleotides copied into new strand
Molecules of Life: Nucleic Acids • Protein Synthesis • Transcription • mRNA: “negative” copy of DNA in nucleus • Translation • tRNA: amino acids make protein structure
DNA Analysis Crime Scene Suspect 1 Suspect 2 Suspect 3 Suspect 4 • Paternity Testing • 50% of DNA from each parent • DNA fingerprinting • Compare evidence to known samples Source: http://www.copernico.bo.it/subwww/webnewbio/webbiotec/html/K5_DNA%20Fingerprinting.html
DNA Manipulation Recombinant Genetics