Download Chapter 5: Structure and Function of Macromolecules

Chapter 5: Structure and Function of Macromolecules
Macromolecules


Giant molecules weighing over 100,000 daltons
Emergent properties not found in component parts
Macromolecules Multiple Units

“meris” = ____________

_______________
  “one part” a relatively small molecule
 May repeat to make a more complex molecules

_______________
  “two parts”
 Complex molecule made of two units of a monomer

____________
  “many parts”
 A long complex molecule made of similar or identical monomers

Dimers & polymers connected by ____________ bonds
Synthesis of Dimers and Polymers

Synthesis by ______________ reactions
 = “______________” reactions
 Because molecule of ______________ lost in process

One monomer contributes H+, other contributes OH-
 Process repeats while building polymer
 Requires ______________ input
 Aided by ______________
Breakdown of Dimers and Polymers
 Broken down by ______________

“water” + “break”
 Bonds between monomers break with addition of ______________

H+ goes on one monomer

OH- goes on the other
 e.g. During digestion

Breakdown large molecules

Redistribute parts

Re-assemble parts into new polymers elsewhere
Four Classes of Macromolecules

______________

______________

______________

______________ ______________
Carbohydrates

______________ – and their polymers
 ___________________ (single, or simple sugars)
 Monomers
 e.g. glucose
 ___________________ (two monosaccharides joined by condensation)
 Dimers
 e.g. sucrose (table sugar)
 ___________________ (many sugars joined by condensation reactions)
 Polymers
 e.g. cellulose
Monosaccharides

Generalized formula: ______________
 e.g. C6H12O6 (glucose)
 Name usually ends in “ – __________ ”
 Multiple hydroxyl groups
 One carbonyl group
 Size of carbon skeleton varies (3-7 carbons long)
 Most common:
______________
______________
______________
Some Monosaccharides – Linear Form
Monosaccharides Form ______________ at Equilibrium
Uses for Monosaccharides

Major source of ______________ for cells
 ______________ most common

Used as component parts in
 Disaccharides (dimers)
 Polysaccharides (polymers)

Carbon skeletons used for ______________ of small organic molecules
 Amino acids
 Fatty acids
Disaccharides

Two monosaccharides joined by ______________ linkage (dehydration reaction)

e.g. maltose (2 glucoses) – ingredient in beer production

e.g. sucrose (glucose + fructose) – transport sugar in plants
Polysaccharides

Polymers of sugars (monosaccharides)
 Several hundred to several thousand monomers

______________ linkages
 Functions related to architecture and position of glycosidic linkages

Two groups of polysaccharides
 ______________ polysaccharides
 ______________ polysaccharides
 Starch
 Cellulose
 Glycogen
 Chitin
Storage Polysaccharides – Starch

______________ – repeating glucose monomers
 Storage in ______________
 Helical form
 Amylose (simplest form) unbranched with 1–4 linkages
 Amylopectin (more complex) branches at 1–6 linkages
Storage Polysaccharides – Glycogen

______________ – repeating glucose monomers
 Storage in ______________ (liver and muscle)
 ______________ storage – not long-term
 Can’t store enough to sustain for more than a day
 Similar to amylopectin, but more branched
Structural Polysaccharides – Cellulose

______________ – found in cell walls in plants
 Polymer of glucose (like starch)
 Every other glucose is upside down
 Due to differential placement of –OH group
 β-glucose has –OH ______________ ring
 α-glucose has –OH ______________ ring
Starch vs Cellulose

______________ with α-glucose 1-4 linkages

______________ with β-glucose 1-4 linkages
Structure of Cellulose

Straight chain (starch is helical)

No branching

______________ bonding between parallel chains
Digestion of Starch and Cellulose

Enzymes that digest starch (α-glucose) cannot digest cellulose (β-glucose)

Most ______________ cannot digest cellulose
 Use cellulose as fiber to aid movement of food through the gut

What can digest cellulose?
 Some ______________
 Some ______________
 Present in the ______________ of cows and other ruminants
(1st compartment of stomach)
 Present in the gut of termites
Structural Polysaccharides – Chitin

Glucose monomer with N-containing branch at #2 carbon

Found in cell walls of ______________

Found in exoskeletons of ______________
 Insects
 Spiders
 Crustaceans (lobsters, shrimp, etc)
Lipids

______________ macromolecules
 Not polymers (________ repeating monomers)
 Smaller than polymeric macromolecules
 Mostly _________________
 ____________ polar bonds
 Grouped together because of ______________ affinity for water

Major groups
 ______________
 Minor groups
 ______________
 Waxes
 ______________
 Some pigments
Lipids – Fats

“_________________”
 Formed by ______________ synthesis

Glycerol + 3 fatty acids
 ______________
 _____ – carbon ______________ chain, each C has -OH
 ______________ acids
 Long ________________ chain w/ carboxyl functional group on end
 May be ______________, or may be 3 ______________ fatty acids
Lipids – Fats

Purpose: ______________ storage
 Much more compact than polysaccharides
 Energy rich (______________, like petroleum)
 Animals use in ______________ (fat) tissue (compact)
 Also protects organs
 Plants use in seeds (compact)
Variation
 ______________ of chains
 ______________of double bonds
 ______________ of double bonds
Fatty Acids and Fats

______________ fatty acid
 ______ double bonds
 All ______________ bonds w/ hydrogen
 Pack ______________ together
 ______________ at room temperature
 Animal origin
Fatty Acids and Fats

______________ fatty acid
 One or more ______________bonds
 ______________ in fatty acid tails
 Can_____ pack tightly
 ______________ at room temperature
 Plant (or fish) origin
 Hydrogenating turns unsaturated into saturated
 (e.g. peanut butter)
Lipids – Phospholipids

Similar to fats
 _____ fatty acid tails (not 3)
 ______________ group on third hydroxyl of glycerol
 Negative charge
 Polar/charged molecules may associate

______________ tail

______________ head
Phospholipid Bilayers in Cell Membrane

______________ bilayer
 Cell membrane components
 Hydrophobic tails to the ______________ of bilayer
 Hydrophilic heads to the ______________ of bilayer
Lipids – Steroids

Lipids with special carbon skeleton

Four fused ______________
 Different functional groups

______________ important
 Precursor to other steroids
 e.g. Testosterone
 e.g. Progesterone
Proteins

From Greek “proteios” = “first place”

Important class of molecules
 More than half the dry-weight of cells

Complex _______________

Multiple _______________ – multiple structures
 Structural ______________
 _______________
 _______________
 _______________
 _______________
 _______________
 Regulate metabolism
 Accelerate specific reactions in cell
 e.g. Estrogens
Building Blocks of Proteins

All proteins are complex polymers
 All use same ________ monomers

Amino Acids (monomers) = _______________
 Amino group and carboxylic acid group

_______________
 Polymer of amino acids

_______________
 One or more polypeptides, folded and coiled
Amino Acids

Organic molecules with both _______________ group and _______________group

Amino group bonded to α (alpha) carbon

“_____” – variable group, or “side chain”

_____________ ______________ determines which amino acid
R-groups

____ different R-groups give ____ amino acids
 From hydrogen to complex chains with ring structures and functional groups

R-group determines
 The _______________ of amino acid
 _______________ or _______________of amino acid
Nonpolar Amino Acids Determined by R-Group
Polar Amino Acids Determined by R-Group
Electrically Charged Amino Acids Determined by R-Group
Linking Peptides: the _______________ Bond
 Peptides linked by peptide bonds

_______________
 Formed by _______________ (condensation) reaction

_______________ (triggered) by enzymes
 Reaction is between _______________ group and _______________ group
 Polypeptide has amino end and carboxyl end

____ – terminus and ____ – terminus
Polypeptide to Protein

Polypeptide – long _______________ of peptides

Protein – _______________ into unique conformation
 How it folds determines function

Four levels of protein structure
 _______________
 _______________
 _______________
 _______________
Primary Structure

Each protein has a unique _______________ of amino acids
 e.g. Lysozyme has 129 amino acids
(enzyme that lyses cells)
 Arranged in a predetermined order
 Arrangement determined by genetics
 20 possible a.a.s at each position
 20129 ways of arranging a.a.s
 Change primary structure, can change rest of _______________ and change
function
Secondary Structure

_______________ or _______________ due to hydrogen bonding

Coils
 _______________ _______________
 e.g. lysozyme

Folds
 _______________ _______________ sheets
 e.g. spider silk – structure makes spider silk very strong
Tertiary Structure

Further _______________ of polypeptide
 “Hydrophobic interaction”
 Clustering of _______________ regions _______________ from water
 _______________ bonding
 Weak
 _______________ bonding
 Weak
 Disulfide bridges between cysteine monomers
 _______________ and very strong
Quaternary Structure

_______________ or _______________ polypeptide units aggregated together
 e.g. collagen
 Fibrous protein w/coiled helices coiled again in supercoil – like rope
 Makes good connective tissue
 e.g. hemoglobin
 Globular protein w/2 α and 2 β chains per hemoglobin molecule
Effect of Amino Acid Substitution

Single amino acid _______________ changes protein _______________

e.g. Normal hemoglobin to abnormal  sickle-cell anemia
 Hemoglobin has 146 a.a.s
 Change glutamine to valine in ONE spot
 Hemoglobin collapses into sickled cells

This variant is encoded on DNA and is inherited
Normal and Sickled Red Blood Cells
Denaturation
 A change in _______________, or folding
 Occurs when conditions change

_______________

_______________concentration

_______________

Change from _______________ to _______________solvent

Other chemicals
___________________

Denaturing makes protein biologically _______________

Some can renature (reverse) when conditions change back

Others are irreversible – e.g. egg whites
Nucleic Acids

_______________ polymers

Two types of nucleic acids
 ________ (Deoxyribonucleic acid)
 OR
 ________ (Ribonucleic acid)

DNA is the repository of information
 _______________ of instructions for making proteins

RNA is the reader, or messenger
 Directs protein synthesis
 Proteins mediate all other processes
DNA

Storehouse of _______________ _______________

Instructions for all cellular and intercellular processes

Does ______ directly participate in those processes
 Doesn’t even oversee processes

Just a repository of the instructions

Must be something to read the instructions and to direct synthesis so processes can
proceed
 ____________
Reading DNA to Make Proteins
 DNA holds information
 ____RNA picks up the information from the DNA

In nucleus in eukaryotes
 mRNA relays information to ribosomes (in cytoplasm)
 Ribosomes made of ____RNA and protein
 ____RNA bring correct amino acids to ribosome

In cytoplasm
 Polypeptide assembled at ribosome
 How many kinds of RNA are used in this process? _______
Nucleotides: Component Parts of Nucleic Acids

Nucleic acid polymers made from _______________ monomers

Each nucleotide composed of ____________ parts
 _______________ group
 _______________ (5-carbon sugar)
 _______________ or
 ____________________
 _______________ base
 Pyrimidines – smaller
 Purines – larger
___________________

6-membered ring of carbon & nitrogen

Three pyrimidines differentiated by functional groups
 _______________ (DNA or RNA)
 ________________ (DNA only)
 ________________ (RNA only)
____________________

6-membered ring of carbon & nitrogen

Plus 5-membered ring fused to first ring

Two purines differentiated by functional groups
 _______________ (DNA or RNA)
 _______________ (DNA or RNA)
____________ucleotides

Many nucleotides linked by phosphate groups and sugar of next nucleotide

Results in repeating _______________ -_______________ backbone

Appendages are nitrogenous bases
 Purines or pyrimidines

_______________ of bases along backbone determines gene (e.g. AGGTAACT)

_______________ = information to make one protein

RNA is _______________ strand – not very long
Double Helix of DNA

DNA is _______________ – stranded – very long

Spiral form, wound around imaginary axis

Sugar-phosphate _______________ are on _______________

Nitrogenous _______________ are in _______________

Bases are paired & held by _______________ bonds
Complementary _______________ _______________
 Each base has a partner that it pairs with

Adenine with Thymine

Guanine with Cytosine

Always a purine with a pyrimadine
 Strands are __________________
 So if one strand reads

AGGTAACTT
 Then the matching strand reads

TCCATTGAA
 Predictable – therefore easy to copy
DNA __________________

DNA must be replicated before cell division

Strands separate

Each one is a _______________ for a new strand to be made

Two identical copies are made

_______________ of DNA makes _______________ (heritability) possible
Mistakes in DNA Replication

Mistakes relatively common
 Usually corrected by enzymes that check

Sometimes mistakes slip through

Next generation of cells will replicate change

_______________ in DNA may _______________resulting _______________
Changing Proteins Help Us Track Evolutionary Relationships

Many changes over _________ results in variation in proteins handed down to offspring

This results in protein differences in different _______________ or groups of organisms

Differences in proteins from two populations may _______________ until the
populations are very different from one another

More _______________ proteins indicate changes a _______________ time ago