Macromolecules Flashcards
What are the four important classes of BIOLOGICAL molecules?
Carbohydrates
Proteins
Nucleic Acid
Lipids
Three classes are macromolecules that are polymers. Name them.
Carbohydrates[Glucose]: source of energy and provide structural support.
Proteins[amino acids]: helps in catalyzing reactions and transporting substances into and out of cells
Nucleic Acid[Nucleotide]:Stores genetic information and function in gene expression.
Lipids are not polymers or macromolecules . True/False.
TRUE
Lipids are group of diverse molecules that do not mix with water and key functions are
#providing energy
#making up cell membranes
#acting as hormones
Define Polymers
is along molecule consisting of many similar or identical building blocks linked by covalent bonds.[Train]
Define monomers
repeated units that serve as the building blocks of polymers are smaller molecule.
Some monomers have function of their own other than forming polymers.
True
Can dehydration and hydrolysis cab used to break down of molecules that are not polymers ?
YES. such as lipids
The large molecules have emergent properties not found in their individual components.
Yes
Carbohydrates serve as
fuel and building material
Carbohydrates includes
sugars and polymers of sugars.
General molecular formula of monosaccharides
CH2O
One eg of monosaccharides
Most common Glucose [C6 H12 O6] aldose sugar.
Fructose isomer of glucose is ketose sugar
Monosaccharides ranges by length
Hexoses
Trioses
Pentoses
Monosaccharides helps in
Not only acts as major fuel for cellular work such as cellular respiration[Glucose]but their carbon skeleton also serves as raw material for the synthesis of other types of small organic molecule such as amino acid and fatty acids.
What happens if monosaccharides are not used in such way
then they incorporated as monomers into disaccharides or polysaccharides.
Disaccharides consists of
two monosaccharides joined by glycosidic bond [covalent bond] by dehydration reaction
[glyco-carbohydrates]
eg of disaccharides
Maltose[two molecules of glucose]—- brewingg beer
Sucrose[table sugar] [two monomers of glucose and fructose]—–plants food from leaves to non-photosynthetic organs.
Lactose: Glucose + Galactose
Disaccharides must be broken down …True / False ?
TRUE
broken down into monosaccharidesto be use for energy by organisms.
Define polysaccharides
are macromolecules with few hundreds or few thousands monosacchaides joined by glycosidic linkages.
Functions of polysaccharides
Storage material–hydrolyzed as needed to provide monosaccharides for cells.
others serves as building material for structures that protect the cells or the whole organisms.
Function of polysaccharides are determined by
its monosaccharides and by the positions of its glycosidic linkages .
Plants stores Starch[a polymer of glucose monomers] in …….
Plastids [chloroplasts]
Does humans have an enzyme that can hydrolyze plant starch,making glucose available as nutients.
Yes
Amylose
Amylopectin
unbranched
branched polymer with 1-6 linkages at he branch points.
Animal storage polysaccharide
Glycogen(polymer of glucose)
like amylopectin but more extensively branched
Vertebrates stores glycogen mainly in
Liver and muscle cells
How the extensive branch in glycogen fits the function of break down?
More free ends are available for breakdown
Structural Polysaccharides
Cellulose which is the major component of the tough cell wall .of the plants.
Chitin,the carbohydrates used in arthropods to build their exoskeleton-hard cases that surround the softer parts of an animal.
Most abundant compound on earth
Cellulose
10^14 Kg [100 billion tons]
like starch cellulose is a polymer of glucose with 1-4 glycosisdic linkages .True or False
Refer pg no 119
Difference in starch and cellulose
Starch molecules is largely helical fitting their functions of efficiency in storing glucose units.
Cellulose is straight.Never branched and some hyroxyl group on its glucose monomers are free to hydrogen bond with the hydroxyls of the other cellulose ,molecules lying parallel to it.
Microfibrils[strong building materials]
In plant cell walls parallel cellulose molecules held together grouped into units called mf.
Insoluble fiber
Cellulose
Enzymes that digest alpha linkages by hydrolyzing the starch is unable to digest cellulose beta linkage due to
different shapes.
Cow can digest cellulose by
other eg Termites , Fungi
Bacteria and protists
Chitin embedded in layer of
Proteins the case is leathery and flexible at first but becomes hardened when the proteins are chemically linked to each other as in insects or encrusted with calcium carbonate as in crabs.
Fungi has chitin or cellulose
Chitin
Chitin vs Cellulose structure
Same as cellulose with beta linkages except of nitrogen attachment.
Lipids[not polymer not macromolecule since it is not big enough]
Fats
phospholipids
steroids
Fats are not polymers but they are large molecule assembled from smaller molecules by dehydration reaction.
True
Fat structure
Glycerol molecule joined to three fatty acids
Glycerol
Fatty acid
1.is an alcohol each each of its three carbons bears OH groups.
2.fatty acid has a long carbon skeleton usually 16-18 carbon atoms in length. The carbon at one end of the skeleton is part of carboxyl group hence fatty acid
Why fatty acids are hydrophobic
due to the presence of non-polar C-H bonds in hydrocarbon chain of fatty acid.
Fats separate from water because
water molecules H-bonds to one another and excludes the fatty acids .
Each fatty acids molecules is joined to glycerol by a dehydration reaction .This results in
Ester linkages [a bond between a OH group and COOH group]
Another name for fatty acids are also called as triacylglycerol and triglyceride
Nearly every = bond in naturally occuring fatty acids is a …..
cis = bond,which creates a kink in the hydrocarbon chain whenever occurs.
saturated fatty acids
since lack the of double bond cause flexibility that allows closely packed [solid at room temp ]
Unsaturated fatty acid
The kinks which prevents the molecules from tightly packing.
unsaturated to saturated can be converted by
adding hydrogen bonds[hydrogenated] allowing them to solidify.
The process of hydrogenating vegetables oils produces both
saturated and unsaturated fats with trans double bonds
Major function of fats
energy storage
A gram of fats stores more than twice as much as energy as a polysaccharides such as starch.
Because plants are immobile that store energy in the form of starch but animals need to carry their energy storage with them..so it is advantage to have more compact reservoir of fuel-fat.(adipose )
Adipose cell function
Long term food reserves which swells and shrink as fat is deposited and withdrawn from storage.
In addition to storage adipose acts as cushion such vital organs as kidneys and a layer of fat beneath the skin insulates the body.
Phospholipids
Major component of cell membrane
Difference in phospholipids and lipids
It has only 2 fatty acid attached to glycerol rather than three.The third OH group is connected to phosphate group[negative charge in the cell]
When phospholipid are added to water
they self-assemble into a double-layered sheet called a bilayer that shields their hydrophobic fatty acid tails from water.
Steroids are lipids made of
four fused rings
Cholesterol
Type of steroid crucial for animals
it is common component of animal cell membrane
precursor from which other steroid such as vertebrates sex hormones are synthesized.
Cholesterol is synthesized in _____
[vertebrates]
Liver [also by diet]
