biological molecules Flashcards
carbohydrates contain three kinds of atoms which are
carbon
hydrogen
oxygen
what are the simplest kinds of carbohydrates
monosaccharide, ex.glucose
what is disaccharide
two molecules of monosaccharide joined together, ex.sucrose and maltose
what is polysaccharide
when many simple sugars join together
carbohydrates has a chain of?
glucose
lipids has a chain of?
fatty acids
protein has a chain of?
amino acids
lipids contain only three kinds of atoms, which are?
carbon
hydrogen
oxygen
what is a fat molecule made of
four smaller molecules joined together, one of these is glycerol attached to three long molecules called fatty acids
protein molecules contain?
carbon
hydrogen
oxygen
nitrogen
small amounts of sulfur
what is a catalyst
substance that increases rate of chemical reaction and doesn’t change
what is an enzyme
protein that functions as biological catalyst
what is the lock and key mechanism
the substrate molecule fits into the active site of the enzyme in a key-lock mechanism
the enzyme is the lock and the substrate is the key
after the end of the reaction the enzyme is not used up
properties of enzymes
1.all enzymes are proteins
2.lower activation energy of metabolic reaction
3.enzymes work best at certain temperature. usually 37
4.enzymes work best at a specific ph
5.they are catalysts
6.enzymes are specific
how does temperature affect enzyme activity
rate of reaction increases as temperature increases, as there is more kinetic energy so more collisions, after reaching optimum temperature enzyme becomes denatured, active site changes
how does pH affect enzyme activity
at optimum ph shape of enzyme active site fits exactly into substrate
below or above ph the shape of active site changes
effect of substrate concentration on enzyme activity
as the substrate concentration increases the rate of reaction increases, due to more collisions between active site of the enzyme and substrate molecules
what are inhibitors
substances that reduce the rate of enzyme catalyzed reaction
what is competitive inhibitors
molecules with similar shape to the substrate, they fit into the active site stopping the substrate from entering
what is non competitive inhibitors
molecules of different shape than the substrate, they attach to other parts of the enzyme, which changes the shape of the whole enzyme
what are immobilized enzymes
enzymes extracted from cells or tissues and used for industrial or medical purposes
uses of immobilized enzymes
1.production of lactose free milk
-some people are lactose intolerant, as they don’t have lactase enzyme which breaks down lactose into glucose and galactose, immobilized lactase is used to produce lactose free milk and is inexpensive
2.conversion of sucrose into glucose and fructose
-invertase is used commercially to break down sucrose to produce a mixture of glucose and fructose called invert syrup, invert syrup is used for sweetening products
3.testing for glucose in blood and urine
-test strips for blood or urine glucose level use two immobilized enzymes, the first one is glucose oxidase which catalayses the oxidation of glucose to gluconic acid and hydrogen peroxide, hydrogen peroxide oxidises a colorless organic substance (XH2) to it’s colored form (X). The second reaction is catalysed by immobilised peroxidase enzyme
advantages of immobilised enzymes over dissolved enzymes
1.enzymes are more stable at high temperatures and are less likely to denature
2.more resistant to changes in pH
3.less likely to be broken down by organic solvents
