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Name ____________________________________ Date ____________ Period _____
Proteins
Raven Ch. 3
Big Idea 2: BIOLOGICAL SYSTEMS UTILIZE FREE ENERGY AND MOLECULAR
BUILDING BLOCKS TO GROW, TO REPRODUCE AND TO MAINTAIN HOMEOSTASIS.
Essential Knowledge:
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All living systems require constant input of free energy.
Organisms capture and store free energy for use in biological processes.
Organisms must exchange matter with the environment to grow, reproduce and maintain organization.
Organisms exhibit complex properties due to interactions between their constituent parts.
Interactions between molecules affect their structure and function.
Variation in molecular units provides cells with a wider range of functions.
Proteins- ___________________________________________
 Most structurally & functionally diverse group
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Function: ______________________________________________
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enzymes- ex: ______________________________________________________
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structure ex: ______________________________________________________
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carriers & transport ex: ______________________________________________________
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cell communication
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signals ex: ______________________________________________________
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receptors
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defense ex: __________________________________
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movement ex: __________________________________
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storage ex: __________________________________
Structure
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monomer = ________________________________
o _____ different amino acids
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polymer = _________________________________
o protein can be ______________________________ chains folded & bonded together
o ________________________ molecules
o complex 3-D shape
_____________________
___________________
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__________________
Amino acids
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Structure
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_________________________
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_________________________
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_________________________
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_________________________
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___________________ group
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different for each amino acid
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confers _____________________ chemical properties to each amino acid
 like 20 different letters of an alphabet
 can make many words (proteins)
Effect of different R groups:
__________________ amino acids
Why are these nonpolar & hydrophobic? ______________________________________________________
__________________________________________________________________________________________
Effect of different R groups:
_________________ amino acids
Why are these polar & hydrophilic? ______________________________________________________
__________________________________________________________________________________________
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Ionizing in cellular waters:
Amino Acids can be:
Sulfur containing amino acids
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Form ____________________________________
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__________________ cross links between _____________________________
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stabilizes 3-D structure
Building proteins
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_________________________________________
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covalent bond between NH2 (___________________) of one amino acid & COOH
(_________________) of another
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C–N bond
_______________
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Polypeptide chains have ____________________
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________________ = NH2 end
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________________ = COOH end
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repeated sequence (_________________) is the polypeptide backbone
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can only grow in _________________ direction
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__________
__________
Protein Structure & Function
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Function depends on structure
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3-D structure
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_________________________________________ into unique shape
__________________ (1°) structure
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Order of _______________________ in _____________________
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amino acid sequence determined by ___________________________
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slight change in amino acid sequence can affect protein’s ____________________ & its
________________________
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even just one amino acid change can make all the difference!
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Sickle cell anemia
___________________________ (2°) structure
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“_______________________________”
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folding along short sections of polypeptide
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interactions between ___________________________
amino acids
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___________________________
 weak bonds between __________ groups
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forms sections of 3-D structure
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_____________________
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_____________________
________________________ (3°) structure
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“_______________________________________”
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interactions between ______________ amino acids
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__________________________ interactions
 cytoplasm is water-based
 __________________ amino acids cluster
away from water
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______________ bonds & _________________ bonds
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_______________________ bridges
 covalent bonds between sulfurs in _______________________ (S–H)
 anchors 3-D shape
______________________________ (4°) structure
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_______________________________________ chain bonded together
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only then does polypeptide become ____________________________________
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______________________ interactions
Protein structure (review)
Protein denaturation
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___________________________ a protein
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conditions that _______________________ H bonds, ionic bonds, disulfide bridges
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_____________________________
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_________________
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_________________
alter ________________________ structure
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alter 3-D shape
destroys _______________________
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some proteins can return to their functional shape after denaturation, many cannot
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