Download Chemistry: (Organic) Biochemistry

Biochemistry: Chemicals of Life
• Organic compounds
• Contain carbon
• Most are covalently bonded
• Example: C6H12O6 (glucose)
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Slide 2.21
Important Organic Compounds:
Carbohydrates
• Characteristics of Carbohydrates
• Water soluble
• Produce 4 Kcal/gram of energy
• Formed by dehydration synthesis
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Slide 2.26
Important Organic Compounds
• Functions of Carbohydrates
• Stored as energy by plants, animals
• Starches
• Glycogen
• Components of larger structural molecules
• Components of nucleic acids
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Slide 2.26
Important Organic Compounds
• 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
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Slide 2.26
Carbohydrates
Figure 2.12a, b
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Slide 2.27
Carbohydrates
• Polysaccharides – long branching chains
of linked simple sugars
• Most are forms of energy storage
•Plants: “starches”
•Animals: glycogen
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Slide 2.29
Carbohydrates
Figure 2.12c
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Slide 2.28
Important Organic Compounds:
Lipids
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
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Slide 2.29
Important Organic Compounds:
Lipids
Functions of Lipids
• Major component of cell membranes
• Stored in living systems
• Pad and protect vital organs
• Basis for steroid hormones
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Slide 2.29
Important Organic Compounds
• Common lipids in the human body
• Neutral fats (triglycerides)
• Found in fat deposits
• Composed of fatty acids and glycerol
• Source of stored energy
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Slide 2.30a
Lipids: Neutral Fats
Figure 2.14a, b
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Slide 2.31
Lipids
• Common lipids in the human body
(continued)
• Phospholipids: important component of
biological membranes
• Polar head
• Hydrophobic tail
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Slide 2.30b
Phospholipids
Slide 2.31
Fig. 2.14
Figure 2.14a, b
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Lipids
• Common lipids in the human body
(continued)
• Steroids
• Include cholesterol, bile salts, vitamin D,
and some hormones
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Slide 2.30b
Cholesterol
Figure 2.14c
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Slide 2.32
Important Organic Compounds:
Proteins
• 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
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Slide 2.33a
Proteins
• 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
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Slide 2.33b
Enzymes
• Act as biological catalysts
• Increase the rate of chemical reactions
Figure 2.16
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Slide 2.34
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:
Nucleic Acids
• Provide blueprint of life
• Nucleotide bases
• A = Adenine
• G = Guanine
• C = Cytosine
• T = Thymine
• U = Uracil
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Slide 2.35
Important Organic Compounds:
Nucleic Acids
• DNA: DeoxyriboNucleic Acid
•Carries all genetic information
•Can replicate itself
• RNA: RiboNucleic Acid
•Directs protein synthesis
•Three kinds: mRNA, tRNA, rRNA
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Slide 2.35
Important Organic Compounds
• Deoxyribonucleic
acid (DNA)
• Forms a double helix
• Replicates before
cell division
• Carries data for
every protein
Figure 2.17c
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Slide 2.36
Deoxyribonucleic acid (DNA)
Fig. 2.19b
• Sugar-phosphate
backbone
• Nitrogenous bases
form “rungs”
• A bonds to T
• C bonds to G
• With hydrogen
bonds
Important Organic Compounds:
Adenosine triphosphate (ATP)
• Chemical energy used by all cells
• Energy is released by breaking high energy
phosphate bond
• ATP is replenished by oxidation of food
fuels
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Slide 2.37
Adenosine Triphosphate (ATP)
Figure 2.18a
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Slide 2.38
How ATP Drives Cellular Work
Figure 2.19
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Slide 2.39
Protein Synthesis
 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
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Slide 3.37
Protein Synthesis
 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
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Slide 3.37
Role of RNA
 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
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Slide 3.38
Transcription and Translation
 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
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Slide 3.39
Protein Synthesis
Figure 3.15
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Slide 3.40