Carbohydrates Flashcards
what are macromolecules
large molecules composed of thousands of covalently connected atoms (carb, protein, nucleic acids)
what are polymers
long molecule consisting of many similar building blocks (monomers) linked by covalent bonds
which of the four classes of life’s organic
molecules contain polymers
carbohydrates
proteins
nucleic acids
what are carbohydrates
includes sugars and their polymers (ex: starch and cellulose)
* the names of sugars typically end in–ose
what are the functions of carbs
- short term energy (sugar)
- intermediate term energy storage (starch from plants and glycogen from animals)
- structural components in cells (cellulose in plants and chitin in fungi)
what is the ratio of carbohydrates
carbon, hydrogen and oxygen in a 1:2:1 ratio (approx.)
what are examples of monosaccharides (3)
- glucose (used in polyemer synthesis)
- fructose (component of table sugar)
- galactose (component of milk sugar)
where is ribose used
used in RNA nucleotides
where is deeoxyribose used
used in DNA nucleotides
what are examples of disaccharides (3)
- sucrose = glu+fru (table sugar, in plants)
- lactose = glu+gal (milk sugar)
- maltose = glu+glu (brewing sugar)
what are examples of polysaccharides (5)
- starch (storage in plants)
- glycogen (sorage in animals)
- cellulose (structural in plants)
- chitin (structural in animals and fungi)
- peptidoglycan (structural in bacteria)
what is the difference between aldoses and ketoses
the location of the carbonyl group (C=O)
what carb is made with aldose
glucose
what carb is made with ketose
fructose
what is the ration of monosaccharides
have molecular formulas that are some multiple of [CH2O]n (1:2:1 ratio)
– where n is a subscipt and a # from 3 to 7
what are the most common sugars
- trioses (3 carbon; smallest sugars)
- pentoses (5 carbon; in DNA)
- hexoses (6 carbon; common sugars)
what are three common monosaccharides that are all hexoses
glucose, galactose, fructose
– all C6H12O6 therefore are structural isomers from one another
what is the most common monosaccharide
glucose: forms a ring structure which is the most common form of living organisms
how can the ring structure of glucose exist
can exist as two isomers, α-glucose and β-glucose. the two isomeric forms differ in the orientation of the OH group at C1
what is the orientation in α-glucose
the OH group at C1 is on the opposite side of CH2OH
what is the orientation in β-glucose
the OH group at C1 is on the same side as CH2OH
what is the end product of photosynthesis in plants
glucose
what happens during cellular respiration
cells oxidize glucose molecules converting the stored energy to a form that can be readily used for cell work
why do mechanisms evolve
mechanisms evolve to maintain the concentration of glucose at constant levels in the blood, which is regulated by the hormones insulin and glucagon produced by the pancreas and transported through the body via blood vessels
what is insulin
insulin can bind to receptors on surface of fat, muscle and liver cells and promote the transport of
glucose inside cells
what is the purpose of insulin
- it’s made in the pancreas, released into the blood stream and then bind to receptors
- a lot of glucose triggers the release of insulin to decrease blood glucose