AP Biology Modified from: Kim Foglia, Explore Biology Chapter 10.3 Regulation of Cell Division.
Chapter 5 The Structure & Function of Macromolecules Slide show modified from Kim Foglia @ .
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Transcript of Chapter 5 The Structure & Function of Macromolecules Slide show modified from Kim Foglia @ .
Chapter 5The Structure &
Function of Macromolecules
Slide show modified from Kim Foglia @ http://www.explorebiology.com
4 MAJOR MACROMOLECULES4 MAJOR MACROMOLECULES
•Carbohydrates•Lipids•Proteins•Nucleic acids
POLYMERSPOLYMERS
Large molecule made by linking smaller subunits together– Monomers (small subunits)– Covalent bonds
Image by Riedell
SEE ANANIMATION
SEE ANANIMATION
CARBOHYDRATESCARBOHYDRATES
http://www.graphic-design.com/Type/sugar/index.html http://www.ifr.ac.uk/SPM/images/Starch%20products.jpg
MONOSACCHARIDESMONOSACCHARIDESSimple sugar moleculesSimple sugar molecules
C6H12O6
http://www.cybercolloids.net/library/sugars/glyceraldehyde.gifhttp://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.htmlhttp://217.60.75.10/llt/biokemi/images/galactose.jpghttp://217.60.75.10/llt/biokemi/images/galactose.jpghttp://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html
C5H10O5
D-glyceraldehyde
C3H6O3
Composed of C,H,O (CH2O)n
3-7 carbonsName often ends in –ose
NUMBERINGNUMBERING•Carbons are numbered•Carbon with carbonyl group
is #1
Is it D or L ?Is it D or L ?
• For sugars with more than one chiral center, the D or L designation refers to the asymmetric carbon farthest from the aldehyde or keto group.
• Most naturally occurring sugars are D isomers.
• D & L sugars are mirror images with same name.
Pentoses and Pentoses and hexoses can hexoses can cyclizecyclizein waterin water
See animationSee animation
• Carbons can be numbered• Carbon with carbonyl group is #1
CARBOHYDRATES SUPPLY ENERGYCARBOHYDRATES SUPPLY ENERGY
Images from: http://www.miranda.com/library.en/Images/Pictures/girls-runners.jpg http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html
Cells burn glucose and store the energy released as ATP
Disaccharides • Use dehydration synthesis to join
TWO sugar molecules
• covalent bond between 2 monosaccharides = GLYCOSIDIC linkage
EX: Sucrose (table sugar) • most common disaccharidehttp://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Biochemistry/bioche1.gif
http://www.biotech.iastate.edu/lab_protocols/HSSB-TLC_images/sucrose.gif
DISACCHARIDESDISACCHARIDES
Glucose + Fructose → Sucrose + H20
Glucose + Glucose → Maltose + H20
Glucose + Galactose → Lactose + H20
POLYSACCHARIDES~ “many POLYSACCHARIDES~ “many sugars” sugars”
Ex: STARCH Ex: STARCH • polymer of αlpha glucose • linked by α 1-4 glycosidic linkages
Function: Energy storage in PLANTSMost animals have the enzymes to hydrolyze starch, too
http://www.langara.bc.ca/biology/mario/Assets/Amylopectin.jpg
http://www.district87.org/biology87/apbio/biochem/Activity6_notes.pdf
POLYSACCHARIDES~ “many POLYSACCHARIDES~ “many sugars” sugars”
TWO KINDS OF STARCH: amylose = unbranched starch
amylopectin = branched starch
http://www.langara.bc.ca/biology/mario/Assets/Amylopectin.jpg
POLYSACCHARIDES~ “many POLYSACCHARIDES~ “many sugars” sugars”
EX: GLYCOGENEX: GLYCOGENalpha 1-4 glycosidic bonds like starchalpha 1-4 glycosidic bonds like starchMore branched than amylopectinMore branched than amylopectin
FUNCTION:FUNCTION: Energy storage in ANIMALS Energy storage in ANIMALS
Stored in liver and muscle tissue
http://www.abcbodybuilding.com/magazine04/scientific.htm
POLYSACCHARIDES~ “many POLYSACCHARIDES~ “many sugars” sugars” FUNCTION: StructuralFUNCTION: Structural
PLANTS ~ CELLULOSEPLANTS ~ CELLULOSEMajor component in cell wallsMajor component in cell wallsMost abundant organic compound on Most abundant organic compound on
EarthEarthbeta (ß) 1-4 glycosidic linkagesbeta (ß) 1-4 glycosidic linkages
• Enzymes that digest starch by hydrolyzing alpha linkages can’t hydrolyze beta linkages in cellulose• Cellulose in human food passes through the digestive tract as insoluble fiber• Some microbes use enzymes to digest cellulose• Many herbivores, from cows to termites, have symbiotic relationships with these microbes
POLYSACCHARIDESPOLYSACCHARIDESFUNCTION: StructuralFUNCTION: Structural
EX: CHITINEX: CHITINStructural polysaccharide made from ß Structural polysaccharide made from ß glucose with a NITROGEN containing group glucose with a NITROGEN containing group attachedattached
Major component of:Major component of: Exoskeletons in Arthropods Exoskeletons in Arthropods Cell walls in Fungi Cell walls in Fungi Dissolvable surgical thread Dissolvable surgical thread
FATTY ACIDS USED CAN :FATTY ACIDS USED CAN :• Be same or different in one molecule• Vary in length• Vary in number/location of double
bonds• Saturated (single bonds)
vs. unsaturated fats (double bonds)
Kink in chain wherever a cis double bondoccurs
FATSFATS
LONG HC chain• NON-POLAR• HYDROPHOBIC
FUNCTION:•Energy storage very rich
2X energy in carbos•Cushions organs•Insulates body
Think whale blubber!
Lipids, IILipids, II
PhospholipidsPhospholipidsHEAD (PHILIC) Glycerol Phosphate group-PO4
-
Negative charge
TAILS (PHOBIC)2 fatty acids
instead of 3
SEE AMOVIE !
PROTEINSPROTEINS
http://images.foodnetwork.com/webfood/images/gethealthy/nutritionalallstars/LeanProteins_header.jpg
PROTEINS ARE MADE FROM AMINO ACID SUBUITS
• Structure– Central carbon– Amino group– Carboxyl group– R group (side chain)
• Variable group• Confers unique chemical properties
•polar (hydrophilic), nonpolar (hydrophobic), acid or base
• Join via DEHYDRATION SYNTHESIS reactions
Each kind of amino acid has a different R Each kind of amino acid has a different R groupgroup
20 different amino acids are used by cells to 20 different amino acids are used by cells to make proteins make proteins
(There are a few other aa’s, but rare)(There are a few other aa’s, but rare)
R GROUPS
See ananimation
POLYPEPTIDESPOLYPEPTIDES
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookCHEM2.htmlhttp://www.cherishedtimedesigns.com/images/BaliCharmBraceletGraduation500.jpg
• POLYMERS OF AMINO ACIDS ARE CALLED POLYPEPTIDES
•DNA determines the amino acid sequence
Image from: http://www.tvdsb.on.ca/saunders/courses/online/SBI3C/Cells/Protein-Structure03.jpg
A functional PROTEIN is not just thepolypeptide chain.
A PROTEIN consists of one or more polypeptide chains twisted, folded, and coiled into aunique molecular shape
What determines the shape?
SEE AN ANIMATION
PROTEIN STRUCTURE & FUNCTIONPROTEIN STRUCTURE & FUNCTION
Function depends on structure• 4 levels of organization• result in 3-D structure
Primary StructurePrimary Structure
Amino acid substitution: in hemoglobin code
sickle-cell anemiaA
T
Secondary StructureSecondary Structurefolding along short sectionsfolding along short sections
• Due to: R group interactions (phobic/philic)
• Alpha Helix:coiling;
• ß Pleated Sheet:parallel;
• Hydrogen bondsbetween adjacentamino acidshold shape
Tertiary StructureTertiary Structureinteractions between side chainsinteractions between side chains
Conformation: irregular contortions from R group bonding
√ hydrophobic √ disulfide bridges √ hydrogen bonds
√ ionic bonds
Functional GroupsFunctional Groups• Sulfhydral Group
• Called: thiols•
http://www.mun.ca/biology/scarr/Disulfide_bridge.htm
DISULFIDE BRIDGESDISULFIDE BRIDGES
STABLIZE 3-D SHAPE
http://sandwalk.blogspot.com/2007/02/disulfide-bridges-stabilize-folded.html
BETWEEN nearbyCYSTEINE amino acids(Notice name change when bonded)
Quaternary StructureQuaternary Structure• Conformation:
2 or more polypeptide chains aggregated into one macromolecule
√ collagen (connective tissue)
√ hemoglobin
See ananimation
WHAT DO PROTEINS DO?WHAT DO PROTEINS DO?
* See page 78 in Campbell for other examples
ENZYMESENZYMEShttp://www.biologie.uni-hamburg.de/b-online/library/cat-removed/enzyme_.gif
Enzymes are protein catalysts that accelerate chemical reactions in living things
Enzymes reduce activation energy required for reaction
Enzymes are specific and fit substrate like a lock and key.
Enzymes are not changed by reaction and are reusable.
http://www.grand-illusions.com/images/articles/toyshop/trick_lock/mainimage.jpg
LEARN MORE
SEE ANIMATIONof AMYLASE
PROTEIN CONFORMATION ALSO DEPENDS ON PHYSICAL ENVIRONMENT
•pH•Salt concentration•Temperature
http://www.desktopfotos.de/Downloads/melt_cd.jpg
http://www.nealbrownstudio.com/adm/photo/163_nb_fried_egg.jpg
See a movieChoose narrated
LEARN MORE
Proteins that have denatured are biologically inactive
Once conditions change, protein may need help returning to its functional shape.
Facilitation of folding
NUCLEIC ACIDSNUCLEIC ACIDS
Nucleic Acids
The main functions of nucleotides are: information storage (DNA), protein synthesis (RNA) energy transfers (ATP and NAD).
Nucleic Acids
Nucleic acids are polymers composed of units known as nucleotides. The main functions of nucleotides are: information storage (DNA), protein synthesis (RNA) energy transfers (ATP and NAD).
Nucleic AcidsNucleic acids are polymers composed of units known as nucleotides.
Nucleotides consist of a pentose (5C) sugar, a nitrogenous base, and a phosphate. Sugar and phosphate alone = nucleoside
Nucleic Acids
The sugars are either:
ribosedeoxyribose
OR
Nucleic Acids Nitrogeneous bases can be:
Purines (Adenine and Guanine) ~ double-ring Pyrimidines (Cytosine, Thymine and Uracil)
~ single-ring
Deoxyribonucleic acid (DNA) Nitrogen base attached to
sugar at C-1
Phosphate attached to sugar at C-5
Phosphate attached to next nucleoside at C-1 by
phosphodiester linkage
Each strand has a 3’ and 5’ end
http://staff.um.edu.mt/acus1/3Molgen.htm
DNADeoxyribonucleic acid (DNA) is the physical carrier of inheritance for 99% of living organisms.
Image from: http://sbchem.sunysb.edu/msl/dna.gif
Deoxyribonucleic acid (DNA)
Deoxyribose sugar
Nitrogeneous bases:A, C, G and T
DOUBLE HELIX sugar & phosphates
make up sides of ladder
nitrogen bases form steps
Deoxyribonucleic acid (DNA)Strands run antiparallel
http://www.biology.arizona.edu/biochemistry/problem_sets/large_molecules/06t.html
Deoxyribonucleic acid (DNA)
Complementary strands H bonds ~ between paired bases van der Waals ~ between stacked bases
http://staff.um.edu.mt/acus1/3Molgen.htm
Nucleic AcidsNucleic Acids• Inheritance based on
DNA replication• Double helix
(Watson & Crick - 1953)
• Based on Rosalind Franklin’s Xray crystallograpy
Ribonucleic acid (RNA)Ribose sugar
Nitrogeneous bases:A, C, G, and U
SINGLE STRANDED
http://www.biology.arizona.edu/biochemistry/problem_sets/large_molecules/06t.html
RNARNA functions in protein synthesis.
There are three types of RNA:
Messenger RNA (mRNA) ~ blueprint for construction of a protein.
Ribosomal RNA (rRNA) ~ construction site where the protein is made.
Transfer RNA (tRNA) ~ truck delivering the proper amino acid to the
site at the right time.
Deoxyribonucleic acid (DNA)Ribonucleic acid (RNA)
DNA → RNA → protein
NUCLEOTIDES can transfer and store energy
Adenosine triphosphate (ATP)
NUCLEOTIDES can transfer and store energy
NAD+
NADP+
FADCoenzyme A
Energy and electron carriers used in photosynthesis andrespiration
More on this next unit!