carbohydrates (biomols) Flashcards
what 3 elements are carbs made from
carbon, hydrogen, oxygen
what are carbs also known as
saccharides/sugars
what monomer units make up carbs
monosaccharides (single sugar unit)(simple sugar)
what are the 3 hexose monosaccharides
glucose, fructose, galactose
what are the 2 pentose monosaccharides
ribose+deoxyribose
when 2 monosaccharides join, what do they form
a disaccharide (complex sugar)
what are the 3 disaccharides
lactose, sucrose, maltose
what monosaccharides make up lactose
glucose + galactose
what monosaccharides make up sucrose
glucose + fructose
what monosaccharides make up maltose
glucose + glucose
what common monosaccharide is in the disaccharides lactose, sucrose, and maltose
glucose
when many monosaccharides join what is formed
a polysaccharide - not sugars (complex carbohydrate)
how is a polysaccharide formed
many condensation reactions. a polysaccharide is ,made up of sugar subunits
what are the 3 polysaccharides
starch, glycogen, cellulose
what bond forms between monosaccharides
glycosidic
what is a hexose/pentose
6 carbons or 5 carbons
how many carbons are in glucose
6 - making it a hexose sugar
what is the role of glucose in living organisms
it is the substrate of aerobic respiration, glucose is released as energy
what are the 2 forms of glucose
alpha glucose + beta glucose, they are isomers of eo
what is the structure of beta glucose
H is on the bottom and the OH is ontop, and the opposite for alpha glucose
how many carbons are in ribose + deoxyribose
5 in each
what is the difference between ribose +deoxyribose
deoxyribose has 4 o2 instead of 5 (has hydrogen instead of hydroxide)
what are the nucleic acids
ribose +deoxyribose
features of monosaccharides
sweet, water soluble, simple sugars, reducing sugars
what reaction occurs when a disaccharide is formed
a condensation reaction (loss of water) happens between 2 monosaccharides, forming a 1-4 glycosidic bond
what is a 1-4 glycosidic bond
a bond between carbon 1 and carbon 4 with another carbon 1 and carbon 4 off another monosaccharide
what is the equation for the formation of maltose
c6.h12.06 + c6.h12.o6 = c12.h22.o11 + h20
how would u make maltose back into2 alpha glucose molecules
it would be a hydrolysis reaction, add water and enzyme maltase to catalyse reaction
all disaccharides are the typical sugar; a reducing sugar, sweet and soluble in water however one disaccharide isn’t like this which one is it
its sucrose, sucrose is not a reducing sugar
what roles do disaccharides have in organisms
- they can easily + quickly be hydrolysed back into the monosaccharides that make them up, then used in cellular respiration (as they’re all made up of a glucose which is a substrate of ar)
- sucrose is the main transport sugar in the phloem
- lactose is the sugar found in mammalian milk, it has a high energy content for suckling young.
what are the energy storage polysaccharides
starch (plant cells)
glycogen (animal cells)
what is starch and what is it made up of
starch is a polysaccharide. its made up of 2 alpha glucose arranged in 2 different ways: amylose + amylopectin
what is the structural strength polysaccharide
cellulose
what is the structure of amylose
long chains of 1,4 linked alpha glucose, coiled into spiral shape helix. stabilised by hydrogen bonds holding the helix shape
what is the structure of amylopectin
branched long chains of 1,4 linked alpha glucose molecules w short side branches 1,6 linked
what is the difference between amylose + amylopectin
amylose is coiled into a helix while amylopectin is long branched chains, and amylopectin has 1,6 linked short side branches.
how does the structure of starch make it a brilliant energy storage molecule in plants
amylose being helix means greater SA great for storing more energy, it also makes it a compact structure so lots can be stored in cell.
amylopectin being branched means there are many end points so glucose molecules can easily be broken off by hydrolysis for use in respiration - therefore amylopectin can provide rapid supply of energy.
starch is a large macromolecule, so its insoluble + unreactive, meaning it can be used as an energy store and wont affect other cellular reactions
what are macromolecules
large molecules
what is the structure of glycogen
long chains of alpha glucose with1,4 glycosidic bonds, highly branched (branch points with 1,6 glycosidic bonds).
glycogen is very similar to amylopectin except its more branched and more compact so its an even greater store of energy than starch
why would animals need an energy storage molecule that’s even more branched than starch for plant cells
animals need faster release of energy to maintain higher cell respiration rate, plants less active than animals., animals need the ability to survive in harsh envts, migrate long distances and complete endurance related activities.
what’s the structure of cellulose
made from beta glucose. beta molecules cant join the same way alpha glucose joins bcos the hydroxyl groups on C1 and C4 are too far apart to react so these groups get flipped 180 (alternate molecules flip upside down), bcos of this it means that cellulose cannot coil or branch. it is a straight chain molecule.
cellulose is made up of microfibrils + macrofibrils.
what bond links many cellulose chains
hydrogen bonds
what are microfibrils
many cellulose chains linked tg by hydrogen bonds, forming strong fibres - microfibrils.
what are macrofibrils
many hydrogen bond linked cellulose chains all joined. even though hydrogen bonds are weak many tg give great strength (cellulose fibres)
how are the cell wall of plants formed
the macromolecules are interwoven and embed into pectin which hold them all in place to from the cell wall of plants.
how does the structure of cellulose make it ideal for the structure of plant cell walls
microfibrils and macrofibrils have high tensile strength due to the glycosidic bonds between all of the individual beta glucose molecules and the hydrogen bonds holding the cellulose chains tg. the macrofibrils are then crisscrossed in pectin to give more strength.
why do plants need cellulose to be so strong
to keep plant upright
when plants take in water by osmosis, they don’t burst and instead become turgid
strong cell wall protects the membrane around plant cells
why cant most animals digest cellulose/why is cellulose very difficult to digest/breakdown
cellulose lacks the enzyme cellulase, this means that cellulose usually passes thru the digestive system of an animal + comes out in the faeces
what is the test for carbs (reducing sugars)
benedict’s test. applies to all of the monosaccharides and most of the disaccharides (except sucrose)
what is the test for carbs (non reducing sugars)
themodifbenedicts test. applies to sucrose
