chapter five pt 1 Flashcards
what are proteins made from
amino acids
what are nucleic acids made from
nucleotides
what are carbohydrates made from
monosaccharides joined by glycosidic linkage
which large biological molecule is not considered a macromolecule?
lipids
4 main classes of important macromolecules for life
carbohydrates, nucleic acids, proteins, lipids
polymers
large molecule consisting of many similar building blocks linked by covalent bonds
monomers
repeating units (smaller molecule) in a polar
condensation reaction
connects monomer to monomer/polymer, where 2 molecules are covalently bonded to each other w/ loss of a molecule
- (building polymer)
what is condensation reaction the same as
dehydration reaction
dehydration reaction
if a water molecule is lost
hydrolysis
reverse of dehydration reaction, adds water molecule back in to break bonds between monomers
- (breaks polymers apart)
main function of carbohydrates
- fuel
- building materials
carbohydrates
both sugars and polymers of sugars (ketoses/aldehydes)
monosaccharides
simplest carbohydrates (sugars)
- either ketose/aldehyde
disaccharides
2 monosaccharides joined by a glycosidic linkage
glycosidic linkage
covalent bond formed between 2 monosaccharides by dehydration reaction
ex of disaccharides
- sucrose (glucose + fructose)
- maltose (glucose + glucose)
- lactose (glucose + galactose
polysaccharides
macromolecules, hundreds/thousands of monosaccharides joined by glycosidic linkage
4 types of polysaccharides
starch, glycogen, cellulose, chitin
starch
- polymer of glucose monomers
- represents stored energy
- alpha 1,4 linkage
- plants
glycogen
- polymer of glucose
- more extensively branched than starch
- breaks down to glucose when demand for energy
- beta 1,4 linkage
- animals
cellulose
polysaccharide that make up cell walls of plant cells
- most abundant organic compound
- provides structure
chitin
polysaccharide carbohydrate used by arthropods (insects, spiders, crustaceans, fungi) to build exoskeletons
difference between starch and glycogen
glycogen more extensively branched and for animals
why can’t we get energy from cellulose
our enzymes can’t digest it
ex. of pentoses (5 C sugars)
- DNA - deoxyribose
- RNA - ribose
ex. of hexoses (6 C sugars)
- glucose
- galactose
- fructose
lipids
hydrophobic molecules that don’t mix with water
what do lipids consist of?
C,H and some O
- mostly hydrocarbon regions
composition of fats
glycerol molecule + 3 fatty acids
fatty acids
has long carbon skeleton (usually 16-18), C at one end is part of carboxyl group (hence acid)
triacylglycerol
fat molecule w/ 3 fatty acids
saturated fatty acid
has all the hydrogen it can holdu
unsaturated fats
has one of more double bonds
- creates kink in tail
uses of fats
- energy storage
- cushions vital organs
phospholipid composition
glycerol + 2 fatty acids + 3rd hydroxyl group joined to phosphate group
what are phospholipids a major component of?
cell membranes (phospholipid bilayer)
- hydrophobic tails, hydrophilic heads
steroids
lipids characterized by 4 fused rings in carbon skeleton + functional group
cholesterol
precursor of many steroids
what else is cholesterol good for?
component of animal cell membranes, synthesizes hormones
ratio of hydrogen to oxygen in carbohydrate
2:1
