BIOMOLECULES. Biologically Important Molecules Biomolecules are biologically important molecules.
Biologically Important Molecules – II !. Biologically Important Molecules I.Water...
-
Upload
brittney-moody -
Category
Documents
-
view
235 -
download
0
Transcript of Biologically Important Molecules – II !. Biologically Important Molecules I.Water...
Biologically Important Molecules – II !
Biologically Important Molecules
I.WaterII.Carbohydrates
II. CarbohydratesA. Structure
1. monomer = monosaccharidetypically 3-6 carbons, and CnH2nOn formula
II. CarbohydratesA. Structure
1. monomer = monosaccharidetypically 3-6 carbons, and CnH2nOn formulahave carbonyl and hydroxyl groups
II. CarbohydratesA. Structure
1. monomer = monosaccharidetypically 3-6 carbons, and CnH2nOn formulahave carbonyl and hydroxyl groupscarbonyl is either ketone or aldehyde
II. CarbohydratesA. Structure
1. monomer = monosaccharidetypically 3-6 carbons, and CnH2nOn formulahave carbonyl and hydroxyl groupscarbonyl is either ketone or aldehydein aqueous solutions, they form rings
II. CarbohydratesA. Structure
1. monomer = monosaccharidetypically 3-6 carbons, and CnH2nOn formulahave carbonyl and hydroxyl groupscarbonyl is either ketone or aldehydein aqueous solutions, they form ringsexamples:
II. CarbohydratesA. Structure
1. monomer = monosaccharide2. polymerization:
dehydration synthesis reaction
II. CarbohydratesA. Structure
1. monomer = monosaccharide2. polymerization3. Polymers = polysaccharides
Disaccharides
Polysaccharides
Polysaccharides
Polysaccharides
The ‘cross-linkages’ in cellulose are not digestible by starch-digesting enzymes, so animals cannot eat wood unless they have bacterial endosymbionts. Decomposing fungi and bacteria also have these enzymes, and can access the huge amount of energy in cellulose.
Polysaccharides
H-bonds link cellulose molecules together
Polysaccharides
glucosamine
II. CarbohydratesA. StructureB. Function
- energy storage (short and long) - structural (cellulose and chitin)
CO2
H2O
Glucose, Cellulose,Starch
Biologically Important Molecules
I.WaterII.CarbohydratesIII.Lipids
III. Lipids - not true polymers or macromolecules; an assortment
of hydrophobic, hydrocarbon molecules classes as fats, phospholipids, waxes, or steroids.
III. LipidsA. Fats - structure
III. LipidsA. Fats - structure
glycerol (alcohol) with three fatty acids
(or triglyceride)
III. LipidsA. Fats - structure
-saturated fats (no double bonds)
Straight chains pack tightly; solid at room temperature like butter and lard.
Implicated in plaque build-up in blood vessels (atherosclertosis)
Animal fats (not fish oils)
III. LipidsA. Fats - structure
-unsaturated fats (no double bonds)
Plant and fish oils
Kinked; don’t pack – liquid at room temperature.
“Hydrogenation” can make them saturated and solid, but the process also produces trans-fats (trans conformation around double bond) which may contribute MORE to atherosclerosis than saturated fats)
III. LipidsA. Fats - structure - functions
- long term energy storage (dense) not vital in immobile organisms (mature
plants), so it is metabolically easier to store energy as starch. But in seeds and animals (mobile), there is selective value to packing energy efficiently.In animals, fat is stored in adipose cells
III. LipidsA. Fats - structure - functions
- long term energy storage (dense) - insulation (subcutaneous fat) - cushioning
III. LipidsA. FatsB. Phospholipids
- structure
Glycerol 2 fatty acids phosphate group (and choline)
Hydrophilic and hydrophobic regions
III. LipidsA. FatsB. Phospholipids
- functionselective membranes
In water, they spontaneously assemble into micelles or bilayered liposomes.
III. LipidsA. FatsB. PhospholipidsC. Waxes
- structureAn alcohol and fatty acid
Wax Alcohol Fatty Acid
CarnubaCH3(CH2)28CH2-OH CH3(CH2)24COOH
BeeswaxCH3(CH2)28CH2-OH CH3(CH2)14COOH
SpermaceticCH3(CH2)14CH2-OH CH3(CH2)14COOH
III. LipidsA. FatsB. PhospholipidsC. Waxes
- structure - function
Retard the flow of water (plant waxes)Structural (beeswax)Signals – waxes on the exoskeleton can signal an insect’s
sexual receptivity.
III. LipidsA. FatsB. PhospholipidsC. WaxesD. Steroids
- structuretypically a four-ring structure with side groupscholesterol and its hormone derivatives
Cholesterol
Biologically Important Molecules
I.WaterII.CarbohydratesIII.LipidsIV.Proteins
IV. ProteinsA. structure
- monomer: amino acids
IV. ProteinsA. structure
- monomer: amino acidsCarboxyl group
Amine group
IV. ProteinsA. structure
- monomer:
amino acids
20 AA’s found in proteins, with different chemical properties. Of note is cysteine, which can form covalent bonds to other cysteines through a disulfide linkage.
IV. ProteinsA. structure
- monomer: amino acids- polymerization: dehydration
synthesis
The bond that is formed is called a peptide bond
IV. ProteinsA. structure
- monomer: amino acids- polymerization: dehydration
synthesis- polymer: polypeptide
IV. ProteinsA. structure
- monomer: amino acids- polymerization: dehydration
synthesis- polymer: polypeptideMay be 1000’s of aa’s longNot necessarily functional (“proteins” are functional polypeptides)Sequence determines the function
IV. ProteinsA. structure
- monomer: amino acids- polymerization: dehydration
synthesis- polymer: polypeptide- protein has 4 levels of structure
1o (primary) = AA sequence
IV. ProteinsA. structure
- monomer: amino acids- polymerization: dehydration synthesis- polymer: polypeptide- protein has 4 levels of structure
1o (primary) = AA sequence2o (secondary) = pleated sheet or
helix
The result of H-bonds between neighboring AA’s… not involving the side chains.
Some proteins are functional as helices - collagen
IV. ProteinsA. structure
- monomer: amino acids- polymerization: dehydration synthesis- polymer: polypeptide- protein has 4 levels of structure
1o (primary) = AA sequence2o (secondary) = pleated sheet or
helix3o (tertiary) = folded into a glob
The three dimensional structure of the protein is stabilized by all types of bonds between the side chains… ionic between charged AA’s, Hydrogen bonds between polar AA’s, van der Waals forces, and even covalent bonds between sulfurs.
IV. ProteinsA. structure
- monomer: amino acids- polymerization: dehydration synthesis- polymer: polypeptide- protein has 4 levels of structure
1o (primary) = AA sequence2o (secondary) = pleated sheet or
helix3o (tertiary) = folded into a glob4o (quaternary) = >1 polypeptide
Actin filament in muscle is a sequence of globular actin proteins…
http://3dotstudio.com/prenhall/muscle.jpg
50 myofibrils/fiber (cell)
IV. ProteinsA. structureB. functions! - catalysts (enzymes) - structural (actin/collagen/etc.) - transport (hemoglobin, cell membrane) - immunity (antibodies) - cell signaling (surface antigens)
IV. ProteinsA. structureB. functions!C. designer molecules
If protein function is ultimately determined by AA sequence, why can’t we sequence a protein and then synthesize it?
IV. ProteinsA. structureB. functions!C. designer molecules
If protein function is ultimately determined by AA sequence, why can’t we sequence a protein and then synthesize it?
Folding is critical to function, and this is difficult to predict because it is often catalyzed by other molecules called chaparones
IV. ProteinsA. structureB. functions!C. designer molecules
If protein function is ultimately determined by AA sequence, why can’t we sequence a protein and then synthesize it?
Folding is critical to function, and this is difficult to predict because it is often catalyzed by other molecules called chaparones
Perhaps by analyzing large numbers of protein sequences and structures, correlations between “functional motifs” and particular sequences will be resolved.