IB Biology Topic C1.1.9 Measurements in Enzyme-catalysed Reactions Revision Notes (SL/HL)

IB Biology Topic C1.1.9 Measurements in Enzyme-catalysed Reactions Revision Notes (SL/HL) | RevisionDojo

Written by official IB examiners

Enzyme Rate Is the Amount of Product Made, or Substrate Used, Per Unit Time

Definition

Reaction rate

The reaction rate is the speed at which substrates are converted into products.

We measure the rate of an enzyme reaction as the product formed per unit time.
We can instead measure the substrate consumed per unit time, since substrate falls as product rises.

Note

Rate is given as an amount changed per unit time, for example cm³ of gas per second or moles per litre per second.

Two Ways to Track the Change Over Time

Fixed-time method
1. Let the reaction run for a set time, then measure how much substrate was used or product was made.
Completion-time method
1. Measure the time taken for a set amount of substrate to be used up.

Tip

The best estimate of enzyme activity is the initial rate, found from the tangent at the start of the curve.
At the start, substrate is plentiful and little product has built up, so the rate reflects the enzyme itself.

Catalase: Measuring Oxygen Released Over Time

Catalase breaks down hydrogen peroxide into water and oxygen.
The oxygen given off is easy to collect, so we can follow the reaction by measuring gas volume.
Reaction vessel
1. Holds the hydrogen peroxide and a source of catalase, such as yeast.
Gas collection
1. A gas syringe or an inverted measuring cylinder records the volume of oxygen produced.

Nice try, unfortunately this paywall isn't as easy to bypass as you think. Want to help devleop the site? Join the team at https://revisiondojo.com/join-us. exercitation voluptate cillum ullamco excepteur sint officia do tempor Lorem irure minim Lorem elit id voluptate reprehenderit voluptate laboris in nostrud qui non Lorem nostrud laborum culpa sit occaecat reprehenderit

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit.

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

Unlock the rest of this chapter with a free account

Enzyme Rate Is the Amount of Product Made, or Substrate Used, Per Unit Time

Definition

Reaction rate

The reaction rate is the speed at which substrates are converted into products.

We measure the rate of an enzyme reaction as the product formed per unit time.
We can instead measure the substrate consumed per unit time, since substrate falls as product rises.

Note

Rate is given as an amount changed per unit time, for example cm³ of gas per second or moles per litre per second.

Two Ways to Track the Change Over Time

Fixed-time method
1. Let the reaction run for a set time, then measure how much substrate was used or product was made.
Completion-time method
1. Measure the time taken for a set amount of substrate to be used up.

Tip

The best estimate of enzyme activity is the initial rate, found from the tangent at the start of the curve.
At the start, substrate is plentiful and little product has built up, so the rate reflects the enzyme itself.

Catalase: Measuring Oxygen Released Over Time

Catalase breaks down hydrogen peroxide into water and oxygen.
The oxygen given off is easy to collect, so we can follow the reaction by measuring gas volume.
Reaction vessel
1. Holds the hydrogen peroxide and a source of catalase, such as yeast.
Gas collection
1. A gas syringe or an inverted measuring cylinder records the volume of oxygen produced.

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic C1.1.9: Measurements in Enzyme-catalysed Reactions Notes

Enzyme Rate Is the Amount of Product Made, or Substrate Used, Per Unit Time

Two Ways to Track the Change Over Time

Catalase: Measuring Oxygen Released Over Time

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Enzyme Rate Is the Amount of Product Made, or Substrate Used, Per Unit Time

Two Ways to Track the Change Over Time

Catalase: Measuring Oxygen Released Over Time

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics