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Biochemistry: Chemicals of LifeBiochemistry: Chemicals of Life
Slide 2.21Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Organic compounds
• Contain carbon
• Most are covalently bonded
• Example: C6H12O6 (glucose)
Important Organic Compounds: Important Organic Compounds: CarbohydratesCarbohydrates
Slide 2.26Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Characteristics of Carbohydrates
• Water soluble
• Produce 4 Kcal/gram of energy
• Formed by dehydration synthesis
Important Organic CompoundsImportant Organic Compounds
Slide 2.26Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Functions of Carbohydrates
• Stored as energy by plants, animals
• Starches
• Glycogen
• Components of larger structural molecules
• Components of nucleic acids
Important Organic CompoundsImportant Organic Compounds
Slide 2.26Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Structure of Carbohydrates
• Contain carbon, hydrogen, and oxygen
• Include sugars and starches
• Classified according to size
• Monosaccharides – simple sugars
• Disaccharides – two simple sugars
•joined by dehydration synthesis
CarbohydratesCarbohydrates
Slide 2.27Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 2.12a, b
CarbohydratesCarbohydrates
Slide 2.29Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Polysaccharides – long branching chains of linked simple sugars
• Most are forms of energy storage
•Plants: “starches”
•Animals: glycogen
CarbohydratesCarbohydrates
Slide 2.28Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 2.12c
Important Organic Compounds: Important Organic Compounds: LipidsLipids
Slide 2.29Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Characteristics of Lipids
• Contain carbon, hydrogen, and oxygen
• Insoluble in water (hydrophobic)
• Greasy
• Produce 9 Kcal/gm energy
• May be saturated or unsaturated
• Formed by dehydration synthesis
Important Organic Compounds: Important Organic Compounds: LipidsLipids
Slide 2.29Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Functions of Lipids
• Major component of cell membranes
• Stored in living systems
• Pad and protect vital organs
• Basis for steroid hormones
Important Organic CompoundsImportant Organic Compounds
Slide 2.30aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Common lipids in the human body
• Neutral fats (triglycerides)
• Found in fat deposits
• Composed of fatty acids and glycerol
• Source of stored energy
Slide 2.31Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 2.14a, b
Lipids: Neutral FatsLipids: Neutral Fats
LipidsLipids
Slide 2.30bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Common lipids in the human body (continued)
• Phospholipids: important component of biological membranes
• Polar head
• Hydrophobic tail
Slide 2.31
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 2.14a, b
PhospholipidsPhospholipids
Fig. 2.14
LipidsLipids
Slide 2.30bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Common lipids in the human body (continued)
• Steroids
• Include cholesterol, bile salts, vitamin D, and some hormones
Slide 2.32Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 2.14c
CholesterolCholesterol
Important Organic Compounds: Important Organic Compounds: ProteinsProteins
Slide 2.33aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Characteristics of Proteins
• Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur
• Subunits are amino acids (aa)
• Amino acids joined by peptide bonds
• Produce 4 Kcal/gm of energy
• Formed by dehydration synthesis
ProteinsProteins
Slide 2.33bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Functions of Proteins
• Provides for construction materials for body tissues
• Act as enzymes, hormones, antibodies, neurotransmitters, some buffers
• Most common biomolecules
• Must be 3-D to function correctly
EnzymesEnzymes
Slide 2.34Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Act as biological catalysts
• Increase the rate of chemical reactions
Figure 2.16
Enzyme Function
Fig. 2.18
• Act to combine substrates
• Do not change
• Do not enter into the reaction
• Only increase the rate of the reaction
Important Organic Compounds: Important Organic Compounds: Nucleic Acids
Slide 2.35Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Provide blueprint of life
• Nucleotide bases
• A = Adenine
• G = Guanine
• C = Cytosine
• T = Thymine
• U = Uracil
Important Organic Compounds: Important Organic Compounds: Nucleic Acids
Slide 2.35Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• DNA: DeoxyriboNucleic Acid
•Carries all genetic information
•Can replicate itself
• RNA: RiboNucleic Acid
•Directs protein synthesis
•Three kinds: mRNA, tRNA, rRNA
Important Organic CompoundsImportant Organic Compounds
Slide 2.36Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Deoxyribonucleic acid (DNA)
• Forms a double helix
• Replicates before cell division
• Carries data for every protein
Figure 2.17c
Deoxyribonucleic acid (DNA)
• Sugar-phosphate backbone
• Nitrogenous bases form “rungs”
• A bonds to T
• C bonds to G
• With hydrogen bonds
Fig. 2.19b
Important Organic Compounds: Important Organic Compounds: Adenosine triphosphate (ATP)
Slide 2.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Chemical energy used by all cells
• Energy is released by breaking high energy phosphate bond
• ATP is replenished by oxidation of food fuels
Adenosine Triphosphate (ATP)Adenosine Triphosphate (ATP)
Slide 2.38Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 2.18a
How ATP Drives Cellular WorkHow ATP Drives Cellular Work
Slide 2.39Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 2.19
Protein SynthesisProtein Synthesis
Slide 3.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Gene: DNA segment that carries a blueprint for building one protein
Triplet Code: 3 DNA nucleotides that “code” for a single amino acid
Requires ATP and enzymes
RNA is essential for protein synthesis
Protein SynthesisProtein Synthesis
Slide 3.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
NOTE: All genetic information is carried by DNA as nucleotide sequences
Proteins differ because of variations in aa sequence and ratio
Mutations result in changes in the proteins that are made
May affect structure and/or function
Role of RNARole of RNA
Slide 3.38Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Transfer RNA (tRNA) Transfers appropriate amino acids to the
ribosome for building the protein
Ribosomal RNA (rRNA) Helps form the ribosomes where proteins
are built
Messenger RNA (mRNA) Carries the instructions for building a
protein from the nucleus to the ribosome
Transcription and TranslationTranscription and Translation
Slide 3.39Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Transcription
Transfer of information from DNA’s base sequence to the complimentary base sequence of mRNA
Translation
Base sequence of nucleic acid is translated to an amino acid sequence
Amino acids are the building blocks of proteins
Protein SynthesisProtein Synthesis
Slide 3.40Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 3.15
