G11 Biology 2017-2018 Enzymes

Июль 24, 2022

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G11 Biology 2017-2018 Enzymes

Содержание

2. Terminology
3. Equipment
4. Revison Continue discussing variables and questions found on practical.
5. Enzymes Substrate Product Active Site Enzyme substrate complex Enzyme Reactant Hydrogen bonds G11 Enzymes
6. Enzymes vocabulary substrate reactant which binds to enzyme enzyme-substrate complex: temporary association product end result of
7. Protein Structure and Bonds Review Which are globular structures that catalyse metabolic reactions. Primary Structure -peptide
8. Secondary Structure Hydrogen bonds between the polypeptide / protein backbone form the alpha and beta shapes
10. Tertiary structures bonds come from interactions between R-groups
11. Quaternary Structure – 2 or more tertiary structure bound together -globular
16. Functions of Enzymes 1. Enzymes are Catalysts reducing the amount of energy to start a reaction
17. Naming conventions 3. Enzymes named for reaction they catalyze sucrase breaks down sucrose proteases break down
18. Properties of enzymes 4. Specific each enzyme works with a specific substrate H bonds & ionic
19. The greater the concentration of the enzyme, the faster the rate of the reaction, provided there
20. 7. Compounds which regulate enzymes Inhibitors molecules that reduce enzyme activity competitive inhibition noncompetitive inhibition feedback
21. Competitive Inhibitor Inhibitor & substrate “compete” for active site penicillin blocks enzyme bacteria used to build
22. Non-Competitive Inhibitor Ihibitor that binds to site other than active site allosteric inhibitor binds to allosteric
23. Irreversible inhibition Inhibitor permanently binds to enzyme competitor permanently binds to active site allosteric permanently binds
24. allosteric inhibitor of enzyme 1 Negative Feedback Inhibition Regulation & coordination of production product is used
25. Graphs
26. Enzyme concentration enzyme concentration reaction rate What’s happening here?!
27. Factors affecting enzyme function Enzyme concentration as ↑ enzyme = ↑ reaction rate more enzymes =
28. Substrate concentration substrate concentration reaction rate What’s happening here?!
29. Factors affecting enzyme function Substrate concentration as ↑ substrate = ↑ reaction rate more substrate =
30. Temperature temperature reaction rate What’s happening here?!
31. Factors affecting enzyme function Temperature Optimum T° greatest number of molecular collisions human enzymes = 35°-
32. Enzymes and temperature Different enzymes function in different organisms in different environments temperature reaction rate human
33. 7 pH pH reaction rate 2 0 1 3 4 5 6 8 9 10 pepsin
34. Factors affecting enzyme function pH changes in pH adds or remove H+ disrupts bonds, disrupts 3D
36. 1. Enzymes What is an Enzyme? Enzymes are proteins What is the structure of an enzyme?
37. What is the structure of enzymes? -1, 2, 3, 4 -amino acids -peptide bonds -specific -globular
38. What is anEnzyme? https://www.youtube.com/watch?v=a_Bxtb-svh8 Enzymes are proteins – comprised of amino acids Enzymes are catalysts –
39. What is the function of enzymes? To help catalyze-speed up---chemical reactions To make or break specific
40. What are some factors that can effect enzyme function? temperature pH substrate concentration of substrate
41. How are enzymes regulated? Competitive inhibition Non competitive inhibition
42. Experiemental Variables
44. Enzyme Revision Enzymes Lock and key Induced fit Practical potato hydrogen peroxide 54 sec https://www.youtube.com/watch?v=a_Bxtb-svh8
45. Fixed Variables in effect of pH practical Fixed - Temperature -Use thermostatically-controlled water bath -If no
46. pH temperature Substrate concentration Enzyme inhibitor
47. temperature Substrate concentration Enzyme inhibitor
49. Скачать презентацию

Слайд 2

Terminology

Слайд 3

Equipment

Слайд 4

Revison
Continue discussing variables and questions found on practical.

Слайд 5

Enzymes
Substrate
Product
Active Site
Enzyme
substrate
complex
Enzyme
Reactant
Hydrogen
bonds
G11 Enzymes

Слайд 6

Enzymes vocabulary
substrate
reactant which binds to enzyme
enzyme-substrate complex: temporary association
product
end

result of reaction
active site
enzyme’s catalytic site; substrate fits into active site

substrate

enzyme

products

active site

Enzyme
substrate
complex

Слайд 7

Protein Structure and Bonds Review
Which are globular structures that catalyse metabolic

reactions.

Primary Structure
-peptide bonds

Secondary Structure
-hydrogen bonds

Tertiary Structure
-R-groups interact
-van der waals
-polar / non polar interactions

Quaternary Structure
-more than one amino acid chain combines

Слайд 8

Secondary Structure Hydrogen bonds between the polypeptide / protein backbone form

the alpha and beta shapes

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Tertiary structures bonds come from interactions between R-groups

Слайд 11

Quaternary Structure – 2 or more tertiary structure bound together -globular

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Слайд 16

Functions of Enzymes
1. Enzymes are Catalysts
reducing the amount of energy

to start a reaction
2. Activation Energy
- The amount of energy it takes for a reaction to begin.

Слайд 17

Naming conventions
3. Enzymes named for reaction they catalyze
sucrase breaks down sucrose
proteases

break down proteins
lipases break down lipids
DNA polymerase builds DNA
adds nucleotides to DNA strand
pepsin breaks down proteins (polypeptides)

Many enzyme end in -ase

Слайд 18

Properties of enzymes
4. Specific
each enzyme works with a specific substrate
H

bonds & ionic bonds
5. Not consumed in reaction
1 enzyme 600,000 reactions / second.
enzymes unaffected by the reaction
6. Factors that effect the reaction rate of enzymes
Enzyme concentration
Substrate concentration
Temperature
pH

Слайд 19

The greater the concentration of the enzyme, the faster the rate

of the reaction, provided there are enough substrate molecules present. Similarly, the greater the concentration of the substrate, the faster the rate of the reaction. The rate will slow down as the substate is used up.

Each enzyme has an optimum temperature at which it works fastest. As temperature increased abour the optimum temperature above the optimum temperature, the enzyme gradually denatures (loses it precise tertiary structure). When denatured it stops functioning. Denaturing may be reversable.

Each enzyme has an optimum pH. Some enzymes operate only within a narrow pH, some have a broader pH range.

Слайд 20

7. Compounds which regulate enzymes
Inhibitors
molecules that reduce enzyme activity
competitive inhibition
noncompetitive inhibition
feedback

inhibition

https://www.youtube.com/watch?v=p2xf1hYvvpg

Comptetitive and NonCompetitive Inhibition Video – 2min

Слайд 21

Competitive Inhibitor
Inhibitor & substrate “compete”
for active site
penicillin blocks enzyme

bacteria
used to build cell walls

Competitive
Inhibitor
Examples:

Слайд 22

Non-Competitive Inhibitor
Ihibitor that binds to site other than active site
allosteric

inhibitor binds to allosteric site
causes enzyme to change shape
some anti-cancer drugs inhibit enzymes involved in DNA synthesis
stop DNA production
stop division of more cancer cells
cyanide poisoning irreversible inhibitor of Cytochrome C, an enzyme in cellular respiration
stops production of ATP

Examples:

Слайд 23

Irreversible inhibition
Inhibitor permanently binds to enzyme
competitor
permanently binds to active site
allosteric
permanently binds

to allosteric site
permanently changes shape of enzyme
nerve gas, sarin, many insecticides (malathion, parathion…)

Слайд 24

allosteric inhibitor of enzyme 1
Negative Feedback Inhibition
Regulation & coordination of production
product

is used by next step in pathway
final product is inhibitor of earlier step
allosteric inhibitor of earlier enzyme
feedback inhibition
no unnecessary accumulation of product

A → B → C → D → E → F → G

https://www.youtube.com/watch?v=DHZtOKyMPRY

Feedback inhibition video- 2min

Слайд 25

Graphs

Слайд 26

Enzyme concentration
enzyme concentration
reaction rate
What’s happening here?!

Слайд 27

Factors affecting enzyme function
Enzyme concentration
as ↑ enzyme = ↑

reaction rate
more enzymes = more frequently collide with substrate
reaction rate levels off
substrate becomes limiting factor
not all enzyme molecules can find substrate

Слайд 28

Substrate concentration
substrate concentration
reaction rate
What’s happening here?!

Слайд 29

Factors affecting enzyme function
Substrate concentration
as ↑ substrate = ↑

reaction rate
more substrate = more frequently collide with enzyme
reaction rate levels off
all enzymes have active site engaged
enzyme is saturated
maximum rate of reaction

Слайд 30

Temperature
temperature
reaction rate
What’s happening here?!

Слайд 31

Factors affecting enzyme function
Temperature
Optimum T°
greatest number of molecular collisions
human enzymes

= 35°- 40°C
body temp = 37°C
Heat: increase beyond optimum T°
increased energy level of molecules disrupts bonds in enzyme & between enzyme & substrate
H, ionic = weak bonds
denaturation = lose 3D shape (3° structure)
Cold: decrease T°
molecules move slower
decrease collisions between enzyme & substrate

Слайд 32

Enzymes and temperature
Different enzymes function in different organisms in different environments
temperature
reaction

rate

human enzyme

hot spring bacteria enzyme

(158°F)

Слайд 33

7
pH
pH
reaction rate
2
0
1
3
4
5
6
8
9
10
pepsin
trypsin
What’s happening here?!
11
12
13
14
pepsin
trypsin

Слайд 34

Factors affecting enzyme function
pH
changes in pH
adds or remove H+
disrupts bonds, disrupts

3D shape
disrupts attractions between charged amino acids
affect 2° & 3° structure
denatures protein
optimal pH?
most human enzymes = pH 6-8
depends on localized conditions
pepsin (stomach) = pH 2-3
trypsin (small intestines) = pH 8

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Слайд 36

1. Enzymes
What is an Enzyme? Enzymes are proteins
What is the structure

of an enzyme? Enzymes have four main structures
What is the function of enzymes? Enzymes are catalysts
What can factors can effect enzymes rates? Factors the Affect Enzymes
How are enzymes regulated? Enzyme Regulation
Designing an experiment using enzymes

Слайд 37

What is the structure of enzymes?
-1, 2, 3, 4
-amino acids
-peptide

bonds
-specific
-globular
-denatured
-enzyme, substrate, product, active site

Слайд 38

What is anEnzyme? https://www.youtube.com/watch?v=a_Bxtb-svh8
Enzymes are proteins – comprised of amino acids
Enzymes

are catalysts – they speed up reactions
Enzymes are essential for the metabolism- hydrolysis and condensation of food to body parts or energy!.
Enzymes are specific – one enzyme, one bond
Enzymes are fast! - 1 enzyme every 600,000 seconds
proteins are chains of amino acids held together by peptide bonds.
there are 20 amino acids

Слайд 39

What is the function of enzymes?
To help catalyze-speed up---chemical reactions
To make

or break specific bonds

Слайд 40

What are some factors that can effect enzyme function?
temperature
pH
substrate
concentration of substrate

Слайд 41

How are enzymes regulated?
Competitive inhibition
Non competitive inhibition

Слайд 42

Experiemental Variables

Слайд 43

Слайд 44

Enzyme Revision
Enzymes
Lock and key
Induced fit
Practical potato hydrogen peroxide 54

sec
https://www.youtube.com/watch?v=a_Bxtb-svh8

Слайд 45

Fixed Variables in effect of pH practical
Fixed - Temperature
-Use thermostatically-controlled water

bath
-If no controlled bath available, at least measure the temperature to check that it remains constant.
-Temperature must be fixed as if affects the number of enzyme-substrate collisions which can lead to product.
Fixed - Enzyme concentration
- Fixed mass of source to provide fixed number of enzyme molecule.
-Fixed surface area of source – fixed number of fixed size potato disks.
-Enzyme concentration must be fixed as if affects the frequency of enzyme-substrate collisions.
Fixed - Substrate concentration
-Fixed volume
-Fixed concentration of hydrogen peroxide solution
-Must be fixed as H2O2 concentration affects frequency/ number of enzyme – substrate collisions.
Not fixed – pH is the independent variable.
pH ins the input variable
-Varied by the use of a range of buffer solutions.
-Affect attraction between enzyme confirmation
-Use wide range pH of 4-8 increments of 0.5 to obtain more accurate value.

Слайд 46

pH
temperature
Substrate concentration
Enzyme inhibitor

Слайд 47

G11 Biology 2017-2018 Enzymes

Содержание

Terminology

Equipment

Revison Continue discussing variables and questions found on practical.

EnzymesSubstrateProductActive SiteEnzyme substrate complexEnzymeReactantHydrogen bondsG11 Enzymes

Enzymes vocabularysubstrate reactant which binds to enzymeenzyme-substrate complex: temporary associationproduct end

Protein Structure and Bonds ReviewWhich are globular structures that catalyse metabolic

Secondary Structure Hydrogen bonds between the polypeptide / protein backbone form

Tertiary structures bonds come from interactions between R-groups

Quaternary Structure – 2 or more tertiary structure bound together -globular

Functions of Enzymes 1. Enzymes are Catalystsreducing the amount of energy

Naming conventions3. Enzymes named for reaction they catalyzesucrase breaks down sucroseproteases

Properties of enzymes4. Specificeach enzyme works with a specific substrate H

The greater the concentration of the enzyme, the faster the rate

7. Compounds which regulate enzymesInhibitorsmolecules that reduce enzyme activitycompetitive inhibitionnoncompetitive inhibitionfeedback

Competitive Inhibitor Inhibitor & substrate “compete” for active sitepenicillin blocks enzyme

Non-Competitive Inhibitor Ihibitor that binds to site other than active siteallosteric

Irreversible inhibitionInhibitor permanently binds to enzymecompetitorpermanently binds to active siteallostericpermanently binds

allosteric inhibitor of enzyme 1Negative Feedback InhibitionRegulation & coordination of productionproduct

Graphs

Enzyme concentrationenzyme concentrationreaction rateWhat’s happening here?!

Factors affecting enzyme function Enzyme concentration as ↑ enzyme = ↑

Substrate concentrationsubstrate concentrationreaction rateWhat’s happening here?!

Factors affecting enzyme function Substrate concentration as ↑ substrate = ↑

Temperature temperaturereaction rateWhat’s happening here?!

Factors affecting enzyme functionTemperatureOptimum T° greatest number of molecular collisionshuman enzymes

Enzymes and temperatureDifferent enzymes function in different organisms in different environmentstemperaturereaction

7pH pHreaction rate20134568910pepsintrypsinWhat’s happening here?!11121314pepsintrypsin

Factors affecting enzyme functionpHchanges in pHadds or remove H+disrupts bonds, disrupts

1. EnzymesWhat is an Enzyme? Enzymes are proteinsWhat is the structure

What is the structure of enzymes? -1, 2, 3, 4-amino acids-peptide

What is anEnzyme? https://www.youtube.com/watch?v=a_Bxtb-svh8Enzymes are proteins – comprised of amino acidsEnzymes

What is the function of enzymes? To help catalyze-speed up---chemical reactionsTo make

What are some factors that can effect enzyme function?temperaturepHsubstrateconcentration of substrate

How are enzymes regulated? Competitive inhibitionNon competitive inhibition