Enzymes and Metabolism Flashcards

Unit 2: Biomolecules

1
Q

Define Catalysts

A

Substances that speeds up a chemical reaction but is unchanged by the reaction

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2
Q

Pros of catalysts

A

They can be used over and over
Less of them required relative to the reactants

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3
Q

Define enzymes

A

They are biological catalysts made by cells that convert substrates into products

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4
Q

What would happen if there were no enzymes in life

A

The life’s processes would be very slow

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5
Q

Define Metabolism

A

Complex network of interdependent and interacting chemical reactions occurring within cells/living organisms

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6
Q

What happends during metabolism

A

Transform one type of molecule into another in a series of small steps
They allow cells to make energy, build and deassemble

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7
Q

What causes metabolism?

A

Most are by an enzyme

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8
Q

What does each enzyme catalyze?

A

They catalyze a specific reaction or a specific group of reactions

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9
Q

What are non-biological catalysts

A

They are not specific like enzymes

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10
Q

What does specificity of enzymes allow?

A

They allow organisms to control metabolism

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11
Q

What is controlling the rate of reaction?

A

Organism making more, making less or temporarily stopping the reaction.

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12
Q

Example of a metabolic cycle?

A

The calvin cycle, a part of photosynthesis

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13
Q

Example of a metabolic chain?

A

Glycolysis, a part of respiration

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14
Q

Define anabolic reactions

A

Building up of complex molecules from simpler ones

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15
Q

How does anabolic reactions occur?

A

They occur via condensation reactions (water being produced as a result)

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16
Q

What is required for an anabolic reactions to occur?

A

Energy

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17
Q

Example of an anabolic reactions

A

The production of glucose by photosynthesis and then in to the polymers starch, cellulose

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18
Q

Define catabolic reactions

A

Breaking down of complex molecules into simpler ones

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19
Q

How does catabolic reactions occur?

A

They occur via hydrolysis reactions (Water is consumed)

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20
Q

What happends to the energy during catabolic reactions

A

Energy is released

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21
Q

Example of a catabolic reactions?

A

Cell respiration

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22
Q

Define substrate

A

Substance that enzymes convert into products

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23
Q

Define active site

A

A special region on surface of enyme that binds to the substrate

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24
Q

What is required for active site reaction to take place?

A

Binding is required

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25
Q

How do substrate and active site bind?

A

When a substrate is near the enzyme the surface properties attract the substrate

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26
Q

What happes when the product detach from the active site?

A

The active site returns to its original state

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27
Q

What happens when a second substrate exists the active site?

A

It binds to another part of the active site and again, changes in both allows bonding

28
Q

What is needed for an enzymatic reaction to occur?

A

The substrate and enzyme must physically collide in the correct orientation to facilitate binding to the active site

29
Q

How can the rate of enzyme catalysis increased?

A

By increasing the molecular motion of the particles (thermal energy)
Increasing the concentration of particles

30
Q

What makes the enzymatic reaction possible?

A

They are possible in aqueous solutions where molecucels are in a constant motion (brownian motion)

31
Q

How to motions of substrates and enzymes differ?

A

Substrate are usually smaller so they mvoe more and faster than enzymes.
But some substrates are large and do not much
Sometimes an enzyme is at a particular site and is fixed to a position

32
Q

How can enzyme structures be modified?

A

They can be modified by external factors such as high temperatures and extreme pH

33
Q

What do external factors that modify the enzyme disrupt?

A

They can disrupt the chemical bonds which are necessary to maintain the shape and chemical properties of the enzyme

34
Q

What is denaturation?

A

What the changes are too great it can’t be reversed

35
Q

What can prevent catalysis after binding?

A

Any changes to the structure of the active site

36
Q

What can also happen by obstructing the active site or altering its shape?

A

Certain molecules (inhibitors) reducing enzyme-substrate interactions

37
Q

Define independent variable (IV)

A

The factor you deliberately change to see what the effect is, usually just one

38
Q

Define control variables (constants)

A

The factors kept the same/constant to ensurea fair test.

39
Q

Define dependent variable

A

The results of the experiment

40
Q

Define reaction rates

A

speed at which substances are converted to products

41
Q

Equation to calculate the reaction rate

A

Reaction rate = Quantity of substance/time

42
Q

What is logarithmic scales

A

Each interval is 10x the previous one

43
Q

When is logarithmic scales useful?

A

Useful when data has large ranges and is difficult to plot the small numbers/see differences
Useful to test if a relationship is truly exponential. Using a log scale a truly exponential scale will be linear

44
Q

Define activation energy

A

The initial rise in energy seen in the graph in the energy input needed before the reaction will occur

45
Q

What happens before being converted to product?

A

Substrates pass through a transition state

46
Q

What is the subsequent drop in energy?

A

It is the energy released by the reaction

47
Q

Define extracellular enzyme

A

Made by ribosome on the rER but released from cells and work outside (exoenzymes)

48
Q

Example of an extracellular enzyme

A

Breakdown of macromolecules during digestion

49
Q

Define intracellular enzymes

A

Made by free ribosomes and used inside the cell (endoenzyme)

50
Q

Example of an intracellular enzymes

A

Enzymes are in the cytoplasm needed for glycolysis

51
Q

What happens in generation of heat energy by the reactions of metabolism?

A

The products contain less energy than the reactants due energy loss being converted to heat

52
Q

What happens when the temperatures drop?

A

Muscles contract, generating heat

53
Q

How is heat generated without making ATP?

A

Brown fat metabolizes when its cold, the fat is then broken down

54
Q

Define pathway

A

Linked series of chemical reactions occurring within a cell

55
Q

What’s a linear pathway?

A

Called a chain

56
Q

What’s a cyclical pathway?

A

Intermediate products are the reactants for the step in the reaction

57
Q

Example of an allosteric site

A

A second active site that some enzymes have where a different specific substanes can bind and unbind, this binding causes interactions that lead to a shape changes in the enzyme

58
Q

What is the allosteric inhibitor?

A

Prevents the original substrate from binding (by chaing enzyme shape)
Catalysis is prevented
The inhibitor in this situation does not compete with the original substrate

59
Q

What is non-competitive inhibitors

A

Inhibitors that does not compete with the original substate, allosteric inhibitor

60
Q

What is an allosteric activator?

A

They bind to the allosteric site but cause activation of the reaction

61
Q

What happens when allosteric inhibitor is bind to an active site?

A

Catalysis is prevented, changing the enzyme’s shape

62
Q

Why are allosteric inhibitors caleld non-competitve inhibitors?

A

The inhibitors do not compete with the original substrate as it has a spot in the opposite side of the active site to connect.

63
Q

What is allosteric activator?

A

Bind to the allosteric site but cause activation of the reaction. Causes the reaction to occur by altering the shape of the active site

64
Q

What is a competitive inhabitor

A

They bind to the active site/ They have similar structure to the substrate, but no reaction will occur when bound.

65
Q

What controls many metabolic pathways?

A

They are controlled by feedback inhibition

66
Q

What is a mechanism based inhibition?

A

Some irreversible inhibitors that target specific substrates, but they remain bonded to the active site