CH5: THE STRUCTURE AND FUNCTION OF LARGE BIOLOGICAL MOLECULES Flashcards
large, complex molecules - carbs, protein, nucleic acids
have unique emergent properties from orderly arrangement of atoms
macromolecules
what are the 4 large molecules of life
carbohydrates, lipids, proteins, nucleic acids
long molecule consisting of many similar or identical building blocks linked by covalent bonds
polymer
the smaller, repeating molecules that are the building blocks of a polymer
monomers
what are the 3 macromolecules
carbs (polymers of sugar and starches)
proteins (polymers of amino acids)
nucleic acids (polymers of nucleotides (DNA, RNA)
specialized macromolecules that speed up chemical reactions such as those that make or break down polymers
usually proteins that ends in ASE
enzymes
reactions in which two monomers are covalently bonded to each other through the loss of a water molecule
short polymer + unlinked monomer - water = longer polymer
dehydration reactions
reverse of the dehydration reaction
disassemble polymers into monomers
longer polymer + water = break bond
hydrolysis
includes sugars and polymers of sugars
carbohydrates
simple sugars/carbs
usually have CH2O (i.e. glucose, the most common)
classified by location of carbonyl group and number of carbons in carbon skeleton
monosaccharides
double sugars, two monosaccharides joined by a glycosidic linkage
disaccharides
a covalent bond formed between two monosaccharides by a dehydration reaction (remove water makes a link to combine 2 sugars)
glycosidic linkage
macromolecules, polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages
composed of at least two sugar building blocks
polymers of sugars, have energy storage and structural roles
polysaccharides
a polymer of only glucose monomers stored by plants
store surplus starch as granules within chloroplasts and other plastids
UNBRANCHED/SOMEWHAT UNBRANCHED
starch
simplest form of starch
amylose
a polymer of glucose that is amylopectin but HIGHLY BRANCHED; stored by animals
glycogen
polymer of glucose with differing glycosidic linkages in the 2 polymers major component of the tough walls that enclose plant cells
MOST ABUNDANT ORGANIC COMPOUND
UNBRANCHED (straight, unflexible)
difference based on two rings for glucose - alpha and beta
cellulose
enzymes that digest starch by hydrolyzing ______ linkages can’t hydrolyze _____ linkages in cellulose
alpha, beta
structural polysaccharide found in animals
builds exoskeletons in arthropods
provides structural support for the cell walls of fungi
used in surgical thread
cicada/locusts leave it behind when hatch
chitin (pronounced kaitin)
mix poorly, if at all with water
NOT POLYMERS (not repeated structures); too small to be macromolecules
mostly hydrocarbon regions (form nonpolar covalent)
lipids
constructed from two kinds of smaller molecules - glycerol and fatty acids
fat
long carbon skeleton, usually 16-18 carbon atoms in length
fatty acid
three-carbon alcohol with a hydroxyl group attached to each carbon
glycerol
three fatty acids linked to one glycerol molecule
most potential energy
triacylglycerol
NO DOUBLE BONDS between carbon atoms
said to be _______ with oxygen
most animal fats: butter, lard, etc that are solid at room temp
saturated fatty acid
how do saturated fats contribute to cardiovascular diseases?
through plaque deposits
unsaturated fats with trans double bonds when hydrogenating vegetable oils
trans fats
converts unsaturated to saturated by adding hydrogen
hydrogenation
HAS DOUBLE BONDS with fewer H atoms on each double bond
safer than saturated
most plant and fish fats - olive oil, etc; liquid at room temp
unsaturated fatty acid
what is the main functions of fat?
long term storage of energy; cushion organs and be insulative
similar to a fat molecule but has only two fatty acids attached to glycerol rather than three
hydrophilic, phosphate containing head
hydrophobic tail (1 tail with kink from double bond)
self assemble without energy needed
phospholipid
lipids characterized by a carbon skeleton consisting of four fused rings
steroids
a type of steroid that is crucial in animals and a precursor from which other steroids are synthesized
high level is highly hydrophobic and bad for health
cholesterol
account for 50% dry mass of most cells
functions: defense, energy storage, transport across and out cell, cellular communication, movement, structural support (very versatile)
protein
selective acceleration of chem rxns - changes chem rxn rate without itself being changed into a different thing in the process
enzymatic proteins
protection against disease - makes antibodies that bond to invaders
defensive proteins
storage of amino acids
storage proteins
moves substances (i.e. channel proteins in cell membrane)
transport proteins
coordination of organism’s activities
signal proteins that bring something to tell the cell what to do (triggers a series of things for the cell to do)
i.e. insulin to regulate sugar
hormonal proteins
response of cell to chemical stimuli - bind to signal molecules to transmit second messengers to trigger something else
receptor proteins
movement - truckers of the cell that transport from one side to the other of a cell or out of it
i.e. striated muscle - actin and myosin (release grab pull to shorten muscle)
contractile and motor proteins
support; polypeptide braided rope; i.e. keratin in hair
structural protein
chemical agents that selectively speed up chemical reactions without being consumed by the reactions
brings 2 things close; protein changes shape and jams two together; can do things without getting used up
catalysts
a polymer of amino acids; unbranched polymers built from amino acids
polypeptide
the covalent bond that joins amino groups to each other through a dehydration reactions
peptide bond
a biologically functional molecule made up of one or more polypeptides, each folded and coiled into a specific 3D structure
protein
an organic molecule with both an AMINO group and CARBOXYL group; 20 types
amino acid
t/f: polypeptides vary in length from few to 1K+ monomers
TRUE
carboxyl end of polypeptide
C-terminus
amino end of polypeptide
N-terminus
a protein’s sequence of amino acids (from amino to carboxyl end)
determined by inherited genetic info
1* Primary Structure
the coiled and folded structure that results from H-bonds between repeating constituents of the polypeptide backbone
H-bonds between backbone in diff sections of polypeptide forms 2 shapes - coiled alpha helix or folded beat pleated sheet
Secondary Structure 2*
a delicate coil held together by H-bonding between every 4th amino acid
alpha helix
folded/bended structure; long sheet
beta pleated sheet
the overall shape of a polypeptide resulting from interactions from the side chains (R-groups) of the various amino acids
more bending, folding, twisting by H-bonds, ionic bonds, hydrophobic interactions, van der waals
Tertiary Structure 3*
contributes to the tertiary structure; _________ parts want to stay in and hydrophilic wants to stay out
hydrophobic interaction
really strong covalent bonds that may further reinforce that protein shape
only those with sulfur in their amino acid - Methionine & Cysteine
disulfide bridges
the overall protein structure that results from the aggregation of these polypeptide subunits
2 or more proteins that have to come together and act as 1 to do something
i.e. collagen, hemoglobin
Quaternary Structure 4*
an inherited blood disorder caused by the substitution of one amino acid (valine) for the normal one (glutamic acid) at a particular position in the beta unit primary structure of hemoglobin, the protein that carries oxygen in red blood cells
shape doesn’t do stuff efficiently
makes you less susceptible to malaria
sickle-cell disease
the change caused by an altered environment that leads to the weak chemical bonds and interactions within a protein may be destroyed; the loss of a proteins native structures
affects physical and chemical conditions
alterations in pH, salt conc, temp, etc can unravel protein
______ protein = biologically inactive
denaturation
used to determine the 3D structure of many proteins
X-ray crystallography
other protein molecules that assist the proper folding of other proteins
Chaperonins
