B5 - enzyme Flashcards
define enzymes
protein that is involved in all metabolic reactions where they function as biological catalysts
define catalyst
a substance which increases rate of reaction without being used up in the reaction
why are enzymes biological catalysts
they’re made in cells
define substrate
molecule which an enzyme acts on
what is the lock and key hypothesis
analogy used to show reaction involving enzymes and substrate
what is the lock
active site of enzyme
7 properties of enzymes
-made of protein
-function as biological catalysts
-re-usable
-active site is specific
-can break down or join substrates
-sensitive to temp. changes
-sensitive to pH changes
what is the key
substrate
what does the substrate do to the enzyme
they bind together
what are complementary
active site and substrate
what are each enzymes (activities sites) to substrate
specific
what do enzymes do
-maintain rate of all metabolic reactions
-at rate that can sustain life
what is it called when enzyme and substrate binds together
enzyme- substrate complex
what breaks down hydrogen peroxide
-catalase
what happens to the substrate after it binds with the enzyme
-it is a products
-diffuses from the active site
-either joined tgt or broken
what is hydrogen peroxide broken down into
- hydrogen peroxide -> water and oxygen
(2H2O + O2)
what causes oxygen gas to foam
liquid detergent
where are enzymes written in a reaction
on top of arrow
3 hazards of experimenting catalase enzyme reaction
-cutting food
- H2O2 is irritant to skin
- H2O2 gets in eyes
3 control measures of experimenting catalase enzyme reaction
-cutting food downwards on a tile
-wash it off, avoid skin contact
-wear googles
which side of the table and graph is the independent variable in
-left of table
-x- axis
what is the optimum temperature in humans for most enzymes
37 C
what is the optimum temperature in plants for most enzymes
-around 25C
what can be said about the optimum temp/ pH level of each enzymes
-enzymes have different optimum temp./ pH levels
define optimum temp
temp where enzyme activity is highest
describe the relationship between rate of reaction and temp
-as temp increases until optimum temp, rate of reaction increases
-after the optimum temp, the rate of reaction decreases
explain why rate of reaction increases as temp increase until optimum temp
-more temp
-more KE in substrate and enzyme
-molecular motion of substrate and enzyme more
-more successful collisions
-more products are formed
-increased rate of reaction
when does an enzyme denature
temp past optimum temp
explain why rate of reaction decreases as temp increase after optimum temp
-molecular motion of enzyme increases so much that it denatures permanently
-bonds that stabilise enzyme’s structure are changed
-active site changes shape- no longer complementary to substrate
-enzyme cannot function
-less products
-decrease rate of reaction
is denaturing irreversible
yes
define KE
-random movement energy by enzyme and substrate
-heat increases this
define successful collisions
-when enzyme and substrate bump into each other with sufficient energy for chemical reaction to take place
define denatured
-when enzyme’s active site changes shape permanently so that itis not complementary to substrate
-caused by high temp and extreme pH
3 hazards of experimenting catalase enzyme reaction in pH levels
-cutting hazard
-corrosive/ caustic/ irritant substance
-allergies
what is pH a measure of
acidity
3 control measures of experimenting catalase enzyme reaction in pH levels
-cut down onto a tile
-wear googles, avoid skin contact
-use tweezer to pick food up
here is pH 2, pH7.5, pH9 found in the body
pH2- stomach
pH7.5- mouth
pH9- small intestine
are enzymes living things
no, they are organic chemicals made by living things
how many amino acids are enzymes made from
22 diff. natural occurring
define anabolic enzymes
enzymes that join substrate to form product
define catabolic enzymes
enzymes that break substrate to form product
does the concentration of enzyme stay the same and why
yes because it is not used up
note: when drawing line of best fit, make sure there is a peak btw 2 of the most active points
