Chapter 5 Flashcards
macromolecules
members of carbs, proteins, nucleic acids (huge molecules)
large biological molecules
carbs, lipids, proteins, nucleic acids
macromolecules are ___, built from ___
polymers, monomers
polymer
long molecule consisting of many similar/identical building blocks linked by covalent bonds
monomers
repeating units of a polymer
connected by dehydration reaction
enzymes
specialized macromolecules that speed up chem reactions
dehydration reaction
when 2 molecules are covalently bonded to each other w/ loss of a water molecule
one monomer provides the OH, other provides H
hydrolysis
disassembles polymers to make monomers, reverse of dehydration synthesis
bond broken w/ addition of a water molecule (eg. digestion)
how many monomers are used in constructing molecules?
40-50 common monomers and a few rare ones
how is it possible to create so many different polymers?
linear sequence is important.
*small molecules common to all organisms are ordered into unique macromolecules
carbohydrates serve as ___ and ___
fuel, building material
carbohydrates
sugars and polymers of sugars
monosaccharides
simple sugars
have molecular formulas that are the multiple of the unit CH2O (eg. glucose, C6H12O6)
molecule has carbonyl group (CO) and multiple hydroxyl groups (OH)
major nutrients for cells
disaccharides
double sugars, 2 monosaccharides joined by covalent bond (glycosidic linkage)
polysaccharides
many sugar building blocks, macromolecules
storage material, hydrolyzed as needed for sugar
building material for structures that protect the cell/whole organism
architect and function determined by sugar monomers and position of glycosidic links
aldose/aldehyde sugar
carbonyl group at end of carbon skeleton
ketose/ketone sugar
carbonyl group in middle of carbon skeleton
most names for sugars end in:
-ose
Can also classify sugars according to:
size of carbon skeleton (3-7)
eg. glucose, galactose (aldehydes), fructose (ketone) = hexoses
eg. ribose (aldehyde), ribulose (ketone) = pentoses
eg. glyceraldehyde (aldehyde), dihydroxyacetone (ketone) = trioses
sugars can also differ in
spatial diversity
glycosidic linkage
covalent bond formed between 2 monosaccharides by a dehydration reaction (e.g.. maltose = 2 glucoses, sucrose = glucose + fructose)
starch
polymer of glucose monomers, stored as granules within plastids
enables plant to stockpile surplus glucose
most glucose in it joined by 1-4 linkages (No 1 carbon to no 4 carbon)
glucose monomers are in alpha config.
glycogen
polymer of glucose like amylopectin, more extensively branched
stored mainly in liver and muscle cells
releases glucose when need for sugar incr.
cellulose
major component of tough walls of plant cells
polysaccharide
glucose monomers in beta config.
never branched
few animals can digest (some animals have cellulose digesting microbes in their stomach, eg. cows, termites)
glucose
has 2 rings (alpha and beta), alpha = water OH on bottom, beta = OH on top
chitin
carb used by arthropods to build exoskeletons, also found in fungi
has beta links, but glucose monomer of chitin has nitrogen-containing appendage
lipids are a diverse group of ___ molecules
hydrophobic
lipids
don’t include true polymers
mix poorly w/ water
mostly hydrocarbon regions
include fats, phospholipids, steroids
fat
smaller molecules, glycerol and fatty acids
3 fatty acid molecules joined to glycerol by ester linkage
fatty acid
long carbon skeleton (16-18)
carbon at one end of skeleton is part of carboxyl group (gives name acid)
ester linkage
bond formed by dehydration reaction between hydroxyl group and carbon group
triacylglycerol
3 fatty acids linked to one glycerol molecules
saturated fatty acid
no double bonds between carbon atoms composing a chain
as many H atoms as poss bonded to carbon skeleton
most animal fats = saturated: HC chains of fact acids (tails) lack double bonds and allows fat molecules to pack together tightly
unsaturated fatty acid
has 1+ double bonds, 1 few H atom on each double-bonded atom
cis double bonds
nearly all double bonds in naturally occurring fatty acids
cause a kink in hydrocarbon
atheroscerlosis
plaques develop within walls of blood vessels, cause inward bulges that impede blood flow and reduce resilience of vessels
caused by died rich in saturated fats
trans fats
unsaturated fats w/ trans double bonds
major function of fats
energy storage
adipose cells/tissue
stock long term food
cushions vital organs
insulates body
phospholipid
has only 2 fatty acids attached to glycerol rather than three; third joined to a phosphate group (neg electrical charge in cell)
additional small charged/polar mole also linked to phosphate group (eg. choline)
two ends of phospholipids are different b/c:
hydrocarbon tails = hydrophobic phosphate group = hydrophilic head form bilayers (cell membranes)
steroids
lipids w/ carbon skeleton consisting of 4 fused rings
distinguished by chem groups attached to the ensemble of rings
cholesterol
steroid crucial in animals
component of anima cell membranes
precursor to other steroids (sex hormones)
synthesized in liver and obtained in diet
high level may contrib. to atherosclerosis
proteins include a diversity of ___, resulting in a wide range of ___
structures, functions
importance of proteins
50%+ of dry mass of most cells
speed up chem reactions
some play role in defense, storage, transport, cell communication, movement, structural support
catalysts
enzymatic proteins that regulate metabolism
chem agents hat selectively speed up chem reactions w/o being consumed by the reaction
proteins are all made of:
20 proteins
polypeptide
polymer of amino acids
protein
biologically function molecule made up of one+ polypeptides, each folded and coiled into specific 3D structure
amino acid
organic molecule w/ amino group and carboxyl group
@ center is an alpha carbon, asymmetric carbon atom partnered w/ amino group, carboxyl group, H atom, variable group symbolized by R
side chain/R
differs w/ each amino acid
enzymatic proteins
selective acceleration of chem reactions
eg. digestive enzymes catalyze hydrolysis bonds in food molecules
defensive proteins
protection against disease (eg. antibodies inactivate and help destroy viruses and bacteria)
storage proteins
storage of amino acids (eg. casein, protein of mile, source of amino acids for baby mammals)
transport proteins
transport of substances (eg. hemoglobin, iron-containing protein of vertebrate blood, transports oxygen fr lungs to other parts of the body, others transport across cell membranes)
hormonal proteins
coordination of organism activities (eg. insulin, hormone secreted by pancreas, causes other tissues to take up glucose, regulating blood sugar concentration)
receptor proteins
response of cell to chem stimuli (eg. receptors built into membrane of nerve cell detect signaling molecules released by other nerve cells)
contractile and motor proteins
movement (eg. motor proteins responsible for undulations of cilia and flagella; actin and myosin proteins responsible for contraction of muscles)
structural proteins
support (eg. keratin = protein of hair, horns, feathers, etc; collagen and elastin proteins provide a fibrous framework in animal connective tissues)
acidic amino acids
have side chains hat are generally neg in charge due to presence of carboxyl group, which usually dissociate at cellular pH, hydrophilic
basic amino acids
amino groups in side chains that are generally positive in charge, hydrophilic
hydrophobic; non polar side chains
glycine, alanine, valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, proline
hydrophilic
serine, threonin, cystein, tyrosine, asparagine, glutamine
electrically charged side chains, hydrophilic
aspartic acid, glutamic acid (acidic)lysine, arginine, histidine (basic)
