Structure and Function of Large Biological Molecules Flashcards
Macromolecule
are polymers built from monomers
monomers
molecules of a polymer (building blocks of polymer)
polymers
many monomers covalently (held on one atom) linked together
Dehydration reaction
polymers are assembled this way, and a H2O molecule is lost in the reaction of combining monomers together
Hydrolysis
polymers are broken down through this and a H2O molecule is added between monomers to break the bond
Diversity of Polymers
small molecules common to all organism ordered into unique macromolecules
Homopolymers
same monomers in chain eg. starch which is polymerized glucose
Heteropolymers
different monomers in chain eg. DNA
Carbohydrates: energy storage
- glycogen in human muscles and liver
- starch in plants
Carbohydrates: energy transport
- glucose in blood
- sucrose in plants
Carbohydrates: building material
- cellulose in plant cell walls
- chittin in arthropod skeletons and fugal cell walls
Carbohydrates: Molecular recognition and communication at the cell surface
-membrane glycoprotein and glycolipids such as MHC complex on the surface of our cells
Monoscacharides
simple sugar, 3-7 carbons
Aldose
possessed aldehyde group HCOR (C=0) at the end
Ketose
possessed ketone group RCOR (C=0) at the middle
Isomeric form
arrangement of groups on asymmetric carbon atom (mirror image)
Straight chain or ring forms
rings form predominates in aqueous solutions at pH 7
Disaccharides
two monosacharides attached to each other by a glycosidic linkage
glycosidic linkage
covalent bond formed between two monosaccharides (same or different) by a dehydration reaction
isomers
orientation of the -H and -OH groups on the #1 carbon
oligosaccharides
several monosaccharides attached together, often covalently linked to the noncytoplasmic side of the protein (glycoprotein) and lipids (glycolipids)
starch
the main storage of polysaccharides of plants and some algae
-shape of helix
amylose
linear polymer of glucose with alpha 1-4 glycosidic linkage (no branches)
amylopectin
similar to amylose except it has alpha 1-6 and branches
Glycogen
main storage of polysaccharide of animals
-similar to amylopectin but branch point are more frequent
amylase
digest starch and glycogen
cellulose
principal component of plant cell wall, most abundant polysaccharide
-glucose linkage beta 1-4
Cellulose structure
- unbranched and straight
- hydroxyl group H bond to those on cellulose molecules lying parallel, forming cables called microfibrils (good building material)
Cellulase
- cows and termites have bacteria in stomach to to make cellulase
- not all animals have this