enzymes

Question 1

state –> chemical reactions are what make you work, and enzymes are what make them work.

Question 2

what is an enzyme

Answer 2

they are catalysts produced by living things

Question 3

what increases the rate of a reaction

Answer 3

• increase in temp
• increase in concentration
• increase in pH
• use of catalysts

Question 4

what is a catalyst

Answer 4

is a substance which increases the speed of a reaction, without being changed or used up in a reaction

Question 5

state –> enzymes reduce the need for high temperatures and we only have enzymes to speed up the useful chemical reactions in the body, these are called metabolic reactions.

Question 6

state –> enzymes are all proteins and all proteins are made up of chains of amino acids, these chains are folded into unique shapes, which enzymes need to do their job

Question 7

are enzymes specific

Answer 7

yes

Question 7

chemical reactions usually involve…

Answer 7

either being split apart of being joined together

Question 7

what is a substrate

Answer 7

a molecule that is changed in a reaction

Question 7

state –> enzymes are rly picky, they usually only speed up one reaction, this is bcs for an enzyme to work a substrate has to be the correct shape in order to fit into the active site.

Question 8

what happens to the reaction when the temp is increased

Answer 8

• higher temp increases the rate at first, the enzymes and substrate have more energy so they move about more and are more likely to collide and form enzyme-substrate complexes
• but if it gets too hot some of the bonds holding the enzyme together break
• this changes the shape of the enzymes active site, so the substrate will no longer fit anymore, the enzyme is denatured
• all enzymes have an optimum temperature where they work best at

Question 9

how does the pH affect the reaction time

Answer 9

• the pH also affects the enzymes, if it is too high or too low the pH interferes with the bonds, holding the enzyme together, This changes the shape of the active site and denatures the enzyme
• all enzymes have an optimum pH where they work best at. Its often has a neutral pH 7, but not always

Question 10

how can you investigate how enzyme activity can be affected by changes in pH

Answer 10

Prepare the Setup:

Label test tubes with different pH values (e.g., pH 4, 6, 7, 8, and 10).
Add equal volumes of pH buffer to each test tube.
Add the Substrate:

Add an equal volume of starch solution to each test tube.
Add the Enzyme:

Add an equal volume of amylase solution to each test tube. Mix the solutions immediately.
Start the Reaction:

Start the stopwatch as soon as the enzyme is added.
Monitor the Reaction:

At regular intervals (e.g., every 30 seconds), take a small sample from each test tube and mix it with iodine solution on a white tile.
Observe the color change:
Blue-black indicates starch is still present.
Yellow-brown indicates starch has been broken down.
Record the Time:

Note the time it takes for the starch to completely disappear (no color change with iodine).
Repeat for Accuracy:

Repeat the experiment multiple times for each pH value to obtain reliable data.