Chapter 4 Flashcards

(91 cards)

1
Q

How is energy measured?

A

As Joules or Calories

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

What are the two types of energy?

A

1) Potential Energy - stored energy
2) Kinetic Energy - energy of motion

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

Define Kinetic Energy

A

Includes Heat Energy which is the movement of atoms;

and Light Energy which is the movement of photons

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

Define Potential Energy

A

Includes Chemical Energy which is the energy stored in chemical bonds

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

What is the first law of Thermodynamics?

A

Energy cannot be created or destroyed, only converted from one form to another or transferred from one object to another

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

What type of energy is used with a dam?

A

Potential energy - the higher the water level (with the dam closed), the more potential energy

Kinetic energy- when the water is released

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

What is the 2nd law of Thermodynamics?

A

Energy conversions are not perfect and are accompanied by increased Entropy

*All systems tend toward disorder*

  • The loss of Energy to Entropy is often observed as heat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define Entropy

A

The Energy that is lost from the system, and cannot be used for further work

*It is the amount of disordeer in a system*

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

_____ are much more random than ______

A

Products are much more random than reactants

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

How does our biological metabolism lose energy as entropy?

A

By giving off heat as we exercise

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

Also as we metabolize ______ or ______ we convert a single molecule into several molecules of ______ and _____

A

Also as we metabolize glucose or sucrose we convert a single molecule into several molecules of CO2 and H2O

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

Summary of the 1st law of Thermodynamics

A

Energy before ——> Energy after
(Reaction)

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

Summary of the 2nd law of Thermodynamics

A

Energy before ——-> 3/4 usable energy + 1/4 Unusable
(reaction)

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

Chemical reactions _______________

Chemical bonds are __________

A

Chemical reactions release or store energy

Chemical Bonds are Potential Energy

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

Some Energy is always lost as _______

A

Entropy

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

Reactants are converted to Products

C6H12O6 + 6O2 ——–> 6H2O +6CO2

how many molecules in each?

A

C6H12O6 + 6O2 = 7 molecules

6H2O + 6CO2 = 12 molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define Exergonic

Example?

A

Net release of energy

The reactants contain more energy than the products

-(delta)G

EX. fire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define Endergonic

Example?

A

Net storage of energy

The products contain more energy than the reactants

+(delta)G

EX. Photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the formula for Gibb’s free Energy?

What do each stand for?

A

(delta) G= (delta)H- T(delta)S
(delta) H = change in enthalpy or heat (potential Energy)
(delta) S = change in entropy

T= temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the differene between enthalpy and entropy?

A

Enthalpy = the transfer of energy

Entropy = disorder = energy lost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does gibb’s free energy allow?

A

Gibb’s free energy allows you to determine whether a reaction will be spontaneous, and under what conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

So both change in ________ and change in ________ dictate whether a reaction is favourable or not

A

So both change in potential energy ((delta)H) and change in entropy ((delta)G) dictate whether a reaction is favourable or not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

A glass of ice melts at room temperature

Ice ———-> water

Is H higher for ice or water?

Is S higher for ice or water?

A

H is higher for water

S is ********

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Ice ——> water

(delta) H =
(delta) S =

So as long as _______ the reaction will be favoured

A

(delta) H is positive- it is an endothermic reation
(delta) S is negative

So as long as T(delta)S>(delta)H the reaction will be favoured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Exergonic Reactions: The products contain more/less energy than the reactants Examples?
The products contain less energy than the reactants Ex. burning wood, cellular respiration \*Free energy decreases\* -G
26
Endergonic Reactions: The products contain more/less energy than the reactants Examples?
The products contain more energy than the reactants EX. dissolving table salt in water, photosynthesis \*Free energy increases\* +G
27
Endergonic reaction: The change in (delta)G tells us whether the reaction will occur \_\_\_\_\_\_\_\_\_\_ What is the formula?
The change in (delta)G tells us whether the reaction will occur without addition of outside energy (delta)G = Gproducts - Greactants
28
Endergonic reaction: A negative (delta)G value suggests the reaction is \_\_\_\_\_
favored to proceed
29
An ________ reaction can be coupled to a _______ reaction to make the overall reaction energetically favourable
An Endergonic reaction can be coupled to a Exergonic reaction to make the overall reaction energetically favourable
30
In cells, the coupled Exergonic reaction is often the \_\_\_\_\_\_\_\_\_\_\_\_
Hydrolysis of ATP
31
ATP stands for? ATP is used by the cell to \_\_\_\_\_\_\_\_
ATP = Adenosine Triphosphate ATP is used by the cell to make unfavourable reactions occur
32
ATP: Entropy \_\_\_\_\_\_ (delta)G is \_\_\_\_\_\_\_
Entropy increases (delta)G is negative
33
ATP is converted to ADP using what?
H2O = hyrdolysis
34
ATP--\> ADP+Pi Exergonic reation breaking down ATP provides energy for \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Exergonic reation breaking down ATP provides energy for endergonic reactions in the cell
35
ADP + Pi ---\> ATP \_\_\_\_\_\_ reactions supply energy for endergonic reaction producing ATP
Exergonic-catabolic reactions
36
Biosynthesis of glutamine is an ______ reaction What is the formula without ATP?
Endergonic reaction Glutamine acid + Ammonia ---\> Glutamine Glu + NH3 ---\>NH2 Glu
37
Wtih ATP: ATP can be hydrolyzed to make \_\_\_\_\_\_\_\_\_\_\_, a reactant with more/less energy. This makes the synthesis of glutamin an ______ reaction What is the formula?
Phospho-glutamic acid more energy Exergonic 1) Glu + ATP ----\> Glu-P + ADP 2) Glu-P + NH3 ----\> Glu NH2
38
Coupling glutamine synthesis with ATP hydrolysis yields an _______ reaction
Exergonic
39
Within cells, many biochemical reactions occur through multi-step reactions called \_\_\_\_\_\_
pathways
40
What is a catabolic pathway?
The breakdown of biological products that has a -(delta)G \*Energy releasing\*
41
What is an anabolic pathway?
Is thought of as building cellular components Has a +(delta)G
42
All Chemical Reactions require __________ to get started What is this called?
All Chemical Reactions require an initial input of energy to get started This is called Activation Energy
43
\_\_\_\_ allows us to store sugar (sucrose) at room temperature for months or years
Activation Energy
44
\_\_\_\_\_\_\_ allow reactions to happen that may not happen otherwise
Enzymes
45
What happens to cells when we eat sugar?
Cells form ATP
46
Activation Energy: \_\_\_\_\_\_\_ reactions can use the energy they release to continue Example?
Exergonic reactions EX. Once you light your BBQ the heat of the flames keeps the propane burning
47
\_\_\_\_\_ reactions will require a continuous energy input
Endergonic \*Keep putting energy in\*
48
What are enzymes? and what are they used for?
Enzymes are _protein_ catalysts They increase the rate of the reaction They arent completely used up in the reaction
49
What are enzymes normally named after?
They are named after the reaction they catalyze Ends in -ase
50
Which Enzyme breaks down Starch?
Alpha-Amylase \*It is produced in our saliva\*
51
# Define the Substrate
It is the reactant EX. Starch
52
# Define the Active Site
Where the substrate bines to the Enzyme \*It has to be in that exact spot\* - Lock and key Analogy
53
What does the enzyme Beta-Lactamase do?
Breaks down the B-Lactam ring of Penicillin
54
How does Penicillin stops bacteria from growing?
By interacting with the enzyme needed for Peptidoglycan biosynthesis (Transpeptidase) \*Penicillin binds to transamylase\*
55
Both Penicillin and the normal substrate can fit the \_\_\_\_\_
Active site
56
The cell wall consists of what?
Of thick peptidoglycan layers
57
Antibiotic Resistance: Penicillin resistance is generally due to what?
Due to an enzyme (Beta-lactamase) that degrades the drug
58
Enzymes are ______ that are/are not consumed by the reaction
Enzymes are catalysts, they are NOT consumed by the reaction
59
The substrate, lactose, binds to the enzyme _______ forming an _________ complex
The substrate, lactose, binds to the enzyme B-galactosidase, forming an enzyme-substrate complex \*Transition state is reached - tightest binding but least stable\*
60
What does B-galatosidase catalyze?
It catalyzes the breakage of the bond between the two sugars of lactose, and the products are released
61
T or F: Enzymes are unable to catalyze another reaction
False; Enzymes can catalyze another reaction
62
Are reactions catalyzed by enzymes still chemical reactions?
Yes therefore the activation energy must still be overcome
63
Do enzymes alter the (delta)G of the reaction?
Yes
64
How do Enzymes decrease the Activation Energy?
Less energy has to be put in the reaction It can do the same thing but at a faster rate
65
Enzymes decrease the Activation Energy required by _________ of the \_\_\_\_\_\_ What does this do to the reaction rate?
Enzymes decrease the Activation Energy required by inducing fit of the substrate It speeds up the reaction rate and energy levels are not changed!!
66
Reactants are brought together in the correct orientation, or charges on the ____ can be masked by the \_\_\_\_\_\_\_
Reactants Enzyme
67
Induced fit can also \_\_\_\_\_\_\_\_\_\_\_. Which ______ the activation energy and can ________ the break down of a reactant
Induced fit can also strain the bonds of a reactant \*Add stress but makes bond less stable\* Which lowers the activation energy and can speed up the break down of a reactant
68
What are the 4 factors affecting Enzyme function?
1) pH 2) Salt Concentration 3) Temperature 4) Availability of Substrate
69
pH: What are most active at pH2?
Stomach digestive enzymes such as pepsin
70
pH: What does low pH do?
They inhibit enzymes by altering their 3D strucure
71
Salt Concentration: What will interfere with the chemical bonds in the enzyme, altering the 3D structure?
High levels of Salt
72
Salt Concentration: What can high levels of salt also cause?
It can also cause the substrate not to bind due to the ionic charge
73
Temperature: At high/low temperature protein will denature altering the 3D shape, affecting the \_\_\_\_\_\_\_\_\_\_
At high temperature protein will denature altering the 3D shape, affecting the lock and key mechanism
74
Just like pH, an enzyme will have an ______ temperature for activity
optimum temperature
75
Availability of Substrate: What happens if there is no available substrate?
Then the enzyme cannot catalyze the reaction
76
Enzymes can be altered by the ______ and \_\_\_\_\_\_
Enzymes can be altered by the reactants and the products
77
\_\_\_\_ can bind to the enzyme active site and block the reactant's access
Inhibitors \*Can't be broken down\*
78
When are substrates unable to bind? Competitive inhibitor molecule resembles _____ and competes for \_\_\_\_\_\_
Unable to bind when the inhibitor is bound to the active site Competitive inhibitor molecule resembles substrate and competes for active site
79
Other types of inhibitors can bind to a remote site on the enzyme an cause what? Which blocks?
And cause a change in the protein shape that block the reactant's access to the active site
80
\_\_\_\_\_\_\_\_\_ is common in complex biological pathways It allows the amount of the ultimate product to be _______ by the cell
Enzyme inhibition is common in complex biological pathways It allows the amount of the ultimate product to be highly regulated by the cell
81
What is feedback inhibition?
As the product becomes more abundant, it blocks the pathway which is required for its synthesis
82
Many drugs are commonly used for?
used to block the activity of specific enzymes EX. Tylenol blocks pain Cholesterol pills lower cholesterol
83
Drugs that block enzyme function: Selective Serotonis Reuptake inhibitors stop, and the enzyme needed for serotonin reabsoption- leaving more serotonin in the synapse between nerve cells This result is \_\_\_\_\_\_
altered brain chemistry
84
What are enzyme cofactors?
Vitamins or metal ions
85
Enzyme Cofactors are often critical for ?
The induced fit of the substrate, or for electron transfer/storage
86
Vitamin b6 is required for the synthesis of?
Amino Acids
87
What is the difference between competitive and non competitive inhibition?
Competitive- 2 fighting for the same spot but only one can bind Noncompetitive - binds to the enzyme making it not work
88
Propane is thermodynamically unstable, why is it kinetically stable? a) It is highly electronegative b) Its breakdown is exergonic (-G) c) Its breakdown is endergonic (+G) d) It has a high activation energy (EA) e) It contains and abundance of oxygen and little hydrogen
d) It has a high activation energy (EA)
89
Compared with competitive inhibition, which of the following statements is correct only for noncompetitive inhibition of an enzyme? a) It changes the conformation of the enzyme b) The inhibitory molecule is similar in shape to the normal substrate c) Inhibition decreases the rate at which the product is made d) It results in the enzyme becoming permanently inactive
a) It changes the conformation of the enzyme
90
What are the laws of thermodynamics?
1) Conversation of energy 2) Entropy - disorder
91
Why are enzymes critical for biological reactions?
1) Lowers the temperature 2) Lower the activation energy (how much is needed to start)