how to make biological molecules (ch. 5)
DESCRIPTION
How To Make Biological Molecules (Ch. 5). Macromolecules. Smaller organic molecules join together to form larger molecules macromolecules 4 major classes of macromolecules: carbohydrates lipids proteins nucleic acids. H 2 O. HO. H. HO. H. HO. H . Polymers. - PowerPoint PPT PresentationTRANSCRIPT
How To Make Biological Molecules(Ch. 5)
Macromolecules• Smaller organic molecules join together to
form larger molecules– macromolecules
• 4 major classes of macromolecules:– carbohydrates– lipids– proteins– nucleic acids
H2O
HO
HO H
H HHO
Polymers• Long molecules built by linking repeating
building blocks in a chain – monomers
• building blocks• repeated small units
– covalent bonds
Dehydration synthesis
H2O
HO
HO H
H HHO
How to build a polymer• Synthesis
– joins monomers by “taking” H2O out• one monomer donates OH–
• other monomer donates H+ • together these form H2O
– requires energy & enzymes
enzymeDehydration synthesisCondensation reaction
You gotta be open to“bonding!
H2O
HO H
HO H HO H
How to break down a polymer• Digestion
– use H2O to breakdown polymers • reverse of dehydration synthesis• cleave off one monomer at a time• H2O is split into H+ and OH–
– H+ & OH– attach to ends
– requires enzymes– releases energy
Breaking upis hard to do!
HydrolysisDigestion
enzyme
2007-2008
Any Questions??
OH
OH
H
H
HO
CH2OH
HH
H
OH
O
Carbohydratesenergy
molecules
Carbohydrates• Carbohydrates are composed of C, H, O
carbo - hydr - ateCH2O
• Function:– energy – energy storage– raw materials – structural materials
• Monomer: sugars• ex: sugars, starches, cellulose
sugar sugar sugar sugar sugar sugar sugarsugar
C6H12O6(CH2O)x
Sugars • Most names for sugars end in -ose• Classified by number of carbons
– 6C = hexose (glucose)– 5C = pentose (ribose)– 3C = triose (glyceraldehyde)
OH
OH
H
H
HO
CH2OH
HH
HOH
O
Glucose
H
OH
HO
O H
HHO
H
Ribose
CH2OH
Glyceraldehyde
H
H
H
H
OH
OH
OC
C
C6 5 3
Functional groups determine function
carbonyl
ketone
aldehyde
carbonyl
Sugar structure5C & 6C sugars form rings in solution
Carbons are numbered
Where do you find solutions
in biology?In cells!
Numbered carbons
C
CC
C
CC
1'
2'3'
4'
5'6'
O
energy stored in C-C bonds
Simple & complex sugars• Monosaccharides
– simple 1 monomer sugars– glucose
• Disaccharides– 2 monomers– sucrose
• Polysaccharides – large polymers– starch
OH
OH
H
H
HO
CH2OH
HH
H
OH
O
Glucose
Building sugars• Dehydration synthesis
glycosidic linkage
|glucose
|glucose
monosaccharides disaccharide
|maltose
H2O
Building sugars• Dehydration synthesis
|fructose
|glucose
monosaccharides
|sucrose
(table sugar)
disaccharide
Let’s go to the videotape!
H2O
Polysaccharides • Polymers of sugars
– costs little energy to build– easily reversible = release energy
• Function:– energy storage
• starch (plants)• glycogen (animals)
– in liver & muscles
– structure• cellulose (plants)• chitin (arthropods & fungi)
Linear vs. branched polysaccharides
starch(plant)
glycogen(animal)
energystorag
e
What doesbranching do?
Let’s go to the videotape!
slow release
fast release
Polysaccharide diversity
• Molecular structure determines function
isomers of glucose structure determines function…
in starch in cellulose
Digesting starch vs. cellulose
starcheasy todigest enzyme
enzyme
cellulosehard todigest
Cellulose • Most abundant organic
compound on Earth– herbivores have evolved a mechanism to digest
cellulose– most carnivores have not
• that’s why they eat meat to get their energy & nutrients
• cellulose = undigestible roughage
But it tasteslike hay!
Who can liveon this stuff?!
Chitin, a different structural polysaccharide
(a) The structure of the chitin monomer.
OCH2OH
OHH
H OH
H
NH
C
CH3
O
H
H
(b) Chitin forms the exo- skeleton of arthropods. This
cicada is molting, shedding its old exoskeleton and emergingin adult form. It is also found in
Fungal Cell Walls.
(c) Chitin is used to make a strong and flexible surgical
thread that decomposes after the wound or incision heals.
OH
Cowcan digest cellulose well; no need to eat other sugars
Gorillacan’t digest cellulose well; must add another sugar source, like fruit to diet
Helpful bacteria• How can herbivores digest cellulose so well?
– BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals
RuminantsTell me aboutthe rabbits,
again, George!
I eatWHAT!
Caprophage
2006-2007
Let’s build some
Carbohydrates!
EATX
Review Questions
1. Polymers of glucose units are used as temporary food storage in both plant and animal cells. Glucose units are connected to one another by 1, 4-linkages to make a linear polymer and by 1, 6-linkages to make branch points.
• (cont.) Polysaccharides of glucose unitsvary in size. The three most commonly encountered are:
Type of Starch
Cell Type Polymer Size
Average Number of 1,4-Bonds Between Branches
Amylopectin Plant 100,000,000 24 to 30
Amylos Plant 500,000 Linear Glycogen Animal 3,000,000 8 to 12
• (cont.) When each polymer bond is made, a water molecule is released and becomes part of the cell water. How many water molecules were released during formation of each of the Glycogen?A. 1,000,000B. 2,000,000C. 2,666,666D. 3,000,000E. 3,300,000
2. Which of the following is a polymer?
A. Simple sugar (aka monosaccharide)B. Carbon atomsC. GlucoseD. CelluloseE. deoxyribose
3. Starch and Glycogen bothI. Serve as energy storage for
organismsII. Provide structure and supportIII. Are structural isomers of glucose
A. I onlyB. II onlyC. I and II onlyD. I and III onlyE. I, II, and III