Enzymes and Scientific skills Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is a catalyst?

A

Catalysts are substances which speed up chemical reactions by lowering the activation energy. Without a catalyst it would take a long time for the particles build up enough energy required for successful collisions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is activation energy?

A

The minimum amount of energy that is required to activate the reactants to undergo chemical change (energy required to start a chemical reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an enzyme?

A

A protein biological catalyst that speeds up the rate of reaction by lowering activation energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are some signs of chemical reactions occurring?

A

-Effervescence
-Colour change
-Temperature change (exothermic or endothermic reactions)
-Light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two types of catalysts?

A

-Chemical
-Biological

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What would happen without enzymes?

A

-Without them, essential reactions like aerobic cellular respiration would occur so slowly that life could not exist.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the active site of an enzyme?

A

-The active site is complementary and specific to the substrate in terms of shape and charge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What needs to happen for an enzyme to work?

A

-For an enzyme to function it relies on successful collisions to happen between the enzyme and the substrate
-Reactions only occur if the particles or molecules collide with the correct orientation and the correct energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the factors affecting enzymes?

A

-1. Concentration (of either enzyme or substrate)
-2. Surface area to volume ratio
-3. Temperature
-4. pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does concentration affect enzyme activity?

A

-Increasing the concentration of enzyme or substrate increases the rate of successful collisions as there is more enzyme or substrate to react with.
-This means that more enyzme-substrate complexes will form and the reaction will occur faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does SA : V affect enzyme activity?

A

The smaller the object, the higher the SA : V ratio
-Higher surface area has the same effect as increased concentration
-More space is available to react which means more enzyme-substrate complexes are formed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does Temperature affect enzyme activity?

A

A higher temperature means a greater amount of kinetic energy,
so more there will be a higher chance of successful collisions and more enzyme-substrate complexes will be formed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does pH affect enzyme activity?

A

Enzymes will function best within certain pH levels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the two things that must happen for enzyme function? (Collision theory)

A

-Molecules will move randomly in solution
-Enzyme and substrate will collide
-If these molecules collide with the correct ORIENTATION and ENERGY, they will be able to bind, and the enzyme can act on the substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens to enzymes at very high temperatures?

A

-The enzyme becomes denatured.
-The bonds that hold together the shape of the active site have been broken
-This means that the active site has changed shape, and it is no longer specific to the substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the average human body temperature?

A

-37 degrees Celsius (range is 36.5-37.5)

17
Q

Describe scaffold:

A

(Key term) this means that…
Example: Describe what happens to an enzyme when the temperature rises above the optimum.
-Denatures. This means that the bonds that hold together the shape of the active site have been broken. This means that the active site has changed shape, and is no longer specific and complemetary to the substrate

18
Q

Explain (why) scaffold:

A

-Because (provide the key term/ background biological information necessary to answer the question)
-Then (what is happening in the situation. Use data/specific evidence if it is given)
-Therefore (what is the outcome/effect)

19
Q

Define Independent variable

A

-The independent variable is a factor that is changed or manipulated in an experiment to determine it’s effect on the dependent variable

20
Q

Define Dependent variable

A

-The dependent variable is a measurement to determine if the change or manipulation of the independent variable has had any effect

21
Q

Define Control variable

A

-A controlled variable is one that is kept constant throughout the experiment, so it is not having an effect on the DV

22
Q

Describe the graph
-https://www.google.com/search?q=Sulphur+emissions+worldwide+graph&tbm=isch&sa=X&ved=2ahUKEwi0krnukMz_AhVQ9jgGHdvXDUYQ0pQJegQIDBAB&biw=1920&bih=933&dpr=1#imgrc=0MvtKr6HZ-rljM

A

As time increases from 1850 to 1980, the emissions of Sulphur dioxide (millions of tonnes) increases from 0 to 150 million tonnes.

23
Q

Describe graph scaffold:

A

As (IV) increases/decreases from (…) to (…), the (DV) increases/decreases/plateaus from (…) to (…).

24
Q

Describe the relationship
-https://www.google.com/search?q=Human+Amylase+Starch+Glucose+graph&tbm=isch&sa=X&ved=2ahUKEwj86PiMl8z_AhUHR2wGHcgbBUIQ0pQJegQIDBAB&biw=1920&bih=933&dpr=1

A

As temperature increases from 0 to 40, the relative reactivity increases from 0 to 80.
As temperature further increases from 40 to 67.5, the relative reactivity decreases from 80 to 0.

25
Q

Explain the graph from 0 to 20 degrees (pre-Enzyme)
-https://www.google.com/search?q=Human+Amylase+Starch+Glucose+graph&tbm=isch&sa=X&ved=2ahUKEwj86PiMl8z_AhUHR2wGHcgbBUIQ0pQJegQIDBAB&biw=1920&bih=933&dpr=1

A

Because the temperature is too low between 0 and 20 degrees C for optimum enzyme activity
Then there is not enough kinetic energy and there are not many successful collisions between starch and amylase
Therefore resulting in low relative amylase reactivity

26
Q

Explain the graph from 40 to 100 degrees (Denatures)
-https://www.google.com/search?q=Human+Amylase+Starch+Glucose+graph&tbm=isch&sa=X&ved=2ahUKEwj86PiMl8z_AhUHR2wGHcgbBUIQ0pQJegQIDBAB&biw=1920&bih=933&dpr=1

A

Because the enzymes start to denature above 40 degrees
Then the enzymes have changed shape and the active site of the enzymes is no longer specific or complementary to the substrate
Therefore there are not many successful collisions until 68 degrees when no collisions occur. The relative reactivity reaches zero.

27
Q

Explain the graph at 40 degrees (optimum)
-https://www.google.com/search?q=Human+Amylase+Starch+Glucose+graph&tbm=isch&sa=X&ved=2ahUKEwj86PiMl8z_AhUHR2wGHcgbBUIQ0pQJegQIDBAB&biw=1920&bih=933&dpr=1

A

Because the enzyme and substrate have optimum function at 40 degrees
Then there will be more successful collisions and more enzyme substrate complexes will be formed.
Therefore the enzyme activity peaks at 40 degrees as the most complexes are formed.

28
Q

Explain the graph between 60 - 100 ug I^-1 (Concentration)
-https://www.google.com/search?q=Enzyme+concentration+and+initial+velocity+formed+graph&tbm=isch&sa=X&ved=2ahUKEwi-nJ7Zncz_AhXVqFYBHcZcAdgQ0pQJegQICBAB&biw=1920&bih=933&dpr=1#imgrc=fVEEtyBxFUNN1M

A

Because the concentration of enzyme increases
Then there will be a higher chance of successful collisions between 60-100 as there is more enzyme for the substrates to bind to
Therefore, as more enzyme substrate complexes will be formed, enzyme activity increase between 60- 100.

29
Q

What do you have to remember when doing explain graph questions?

A

PROVIDE CONTEXT IN EITHER THE “BECAUSE” OR “THEN” STATEMENT.

30
Q

What should a collection method include?

A

-Numbered steps
-One point per step
-The names of any laboratory equipment used
-Clear quantities, temperatures and timings
-At least two controlled variables
-Repeats (at least 5 times)

31
Q

Scaffold for collection method:
-Remember to put 2 control variables

A

In the experimental group, (dependent variable) is changed by (independent variable).
1. Add… to a flask
2. Add
3. Put this in/add (control variable)
4. Measure (dependent variable) by using stop watch etc
5. Repeat steps 1 to 4 for (other independent variables)
6. Repeat whole experiment 5 times

32
Q

What should you always include in a explain question?

A

-Enzymes
-Enzyme-substrate complexes
-Successful collisions