Chapter 6- PowerPoint Lectures Flashcards
1
Q
What is the capacity to do work?
A
energy
2
Q
What are the two types of energy?
A
kinetic and potential
3
Q
Energy of motion?
A
kinetic energy
4
Q
stored energy?
A
potential energy
5
Q
In a chemical reaction where is the energy transfered?
A
between reactants and products, and surroundings
6
Q
What is the energy released or absorbed during the chemical reaction called?
A
energy of formation
7
Q
What are the three types of systems?
A
isolated, closed, and open
8
Q
All living organisms are what type of systems?
A
open
9
Q
Which system doesn’t exchange material or energy with its surroundings?
A
iosolated
10
Q
Which system exchanges only energy with its system? —doesn’t exchange matter
A
closed
11
Q
Which system exchanges energy and matter with its surroundings?
A
open
12
Q
What’s the first law of thermodynamics?
A
energy can be transformed from one form to another, but cannot be created or destroyed
13
Q
What is the second law of thermodynamics?
A
entropy always increases
14
Q
What is entropy?
A
disorder
15
Q
What are spontaneous reactions?
A
reaction that doesn’t need input of energy
16
Q
What two factors do you need to consider to determine if a reaction is spontanous?
A
change in energy content of a system and change in entropy
17
Q
Reaction that have less energy in the products than the reactant tend to be?
A
spontaneous
18
Q
reactions that absorb energy?
A
endothermic
19
Q
Gibb’s free energy equation?
A
delta g = delta H- (T delta S)
20
Q
In spontaneous reaction delta G is?
A
negative
21
Q
What is delta G equal to in equilibrium?
A
0
22
Q
What is the symbol for a reversible reaction?
A
double arrow
23
Q
Equilibrium?
A
state of balance between opposing factors pushing the reaction in either direction
24
Q
When do you use the terms exothermic and endo thermic?
A
when refering to heat
25
When do you use the terms exergonic and endergonic?
when referring to delta G
26
When do you use the terms exothermic and endothermic?
when referring to heat
27
Which reactions releases free energy and delta G is negative?
exergonic reactions
28
Which reactions must gain free energy from the surrounding to form products. also delta G is positive?
endergonic reactions
29
What type of reaction has more free energy in the reactants than products?
exergonic reactions
30
What type of reaction has more free energy in the products than reactants?
endergonic reactions
31
What does the graph look like for a exergonic reactions?
downward sloping hill
32
What does the graph look like for a endergonic reactions?
upward sloping hill
33
Is endergonic or exergonic reactions spontaneous?
exergonic
34
What are the two types of metabolic pathways?
catabolic and anabolic
35
What is a metabolic pathway?
series of reactions, where products of one reaciton are used as the reactant in the next reaction
36
In a catabolic pathway is energy released?
yes
37
Which metabolic pathway breaks down complex molecules to simpler compounds?
catabolic
38
What is the overall delta G for a catabolic pathway?
negative
39
What can an anabolic reaction also be called?
biosynthetic reaction
40
Where is energy stored in ATP
triphosphate group
41
what can ADP be hydrolyzed to?
AMP
42
what can ADP be hydrolyzed to?
AMP
43
What is the structure of ATP?
adenine, ribose, 3 phosphate
44
What is the structure of ADP?
adenine, ribose, 2 phosphate
45
What is the structure of AMP?
adenine, ribose, 1 phosphate
46
What is energy coupling?
when ATP is hydrolyzed
47
What is adding a phosphate group called?
phophorylation
48
What is the main energy component in the cell?
ATP
49
How is ATP continually synthesized?
ATP/ADP cycle
50
How many ATP are hydrolyzed and resynthesizes each second in a cell?
10 million
51
How does the structure of the ATP molecule store and release energy?
stored in the terminal phosphate bond, release when it is broken
52
How are coupled reactions important to cell function?
cells have both spontaneous and non-spontaneous reactions, need a source of energy for the non-spontaneous reactions
53
How are coupled reactions important to cell function?
cells have both spontaneous and non-spontaneous reactions, need a source of energy for the non-spontaneous reactions
54
Does the total amount of energy in the universe change in entropy?
no
55
Do living organisms decrease in entropy as they grow?
they seem too, but when nutrients and waste products are considered, total energy is constant and entropy increases
56
What is enthalpy?
potential energy in a system
57
What is the symbol for enthalpy?
H
58
What is the portion of energy in a system that is available to do work called?
free energy
59
What is delta S?
change in entorpy
60
As a system moves toward equilibrium free energy?
decreases
61
Do most reactions in living organisms reach equilibrium?
no b/c open systems where reactants are constant and products do not accumulate
62
When do organisms reach equilibrium?
when they DIE!!!
63
Which metabolic pathway build complicated molecules?
anabolic pathways
64
What is it called when an atom or molecule loses an electron?
oxidation
65
What is it called when an atom or molecule gains an electron?
reduction
66
What is a reduction and oxidation reaction called?
redox
67
What makes bonds unstable and ready to be broken?
activation energy
68
What do enzymes do?
lower activation energy
69
Do enzymes take part in the reaction?
no, remains the same in the beginning and the end
70
what are enzymes made of?
proteins
71
What is activation energy?
energy need to start a reaction
72
What is a catalyst?
lowers Activation energy and accelerates the rate of the reaction
73
Is an enzyme a catalyst?
yes
74
Do enzymes and catalysts affect delta G?
No
75
Are all enzymes are proteins?
yes
76
Are all proteins enzymes?
No
77
What do enzymes end with?
-ase
78
Can enzymes be reused?
yes
79
Do enzymes exist only in the cell?
No, they exist inside and outside the cell
80
Is lysozyme and enzyme?
yes
81
What is the active site?
small pocket or grove in the enzyme that the substate interacts with
82
What is a substrate?
what the enzyme acts on
83
Each enzyme catalyzes a single type of substate is referred to as?
enzyme specificity
84
What happens to the shape when the substrate binds to active site? what is it called?
both enzyme and substrate are distorted, making bonds ready for action
called induced fit
85
What happens after enzyme-substrate is formed?
substrate is converted to one or more products
86
What enzyme is associate with sucrose?
sucrase
87
What does sucrase do?
breaks down sucrose into glucose and fructose
88
Do we need enzymes in large quantities?
No
89
What is a cofactor?
nonprotein group that binds to enzyme
90
examples of cofactors?
metallic ions
91
What are coenzymes?
other cofactors are small organic molecules
92
Where are coenzymes often derived from?
vitamins
93
Which coenzymes bind tightly to enzymes?
prosthetic groups
94
What is superoxide diasmutase (SOD)?
free radical scavenger (bad)
95
What is superoxide diasmutase cofactors?
copper and zinc
96
What are the 3 ways enzymes stablize transition state?
bring reacting molecules together, changing shape of substate molecule, exposing reactant molecules to altered charge environment that promotes catalysis
97
What affects enzyme activity?
concentration of substate (concentration of cofactors), temperature, pH, control mechanisms
98
Does enzyme activity increase with increasing temperatures?
yes, until its optimal temperature
99
If substrate concentration increases/high will enzyme activity increase?
yes
100
What mechanisms regulate enzymes?
competitive and noncompetitive inhibition, allosteric regulation, removal or addition of chemical groups to the enzyme
101
What type of inhibitor is Asprin?
reversible competitive inhibitor
102
What does Aspirin inhibit?
enzyme cyclo-oxygenase
103
What type of inhibitor is Penicillin?
irreversible competitive inhibitor
104
What type of inhibitor is cyanide and metal ion poisoning?
noncompetitive inhibitors
105
What do competitive inhibitors do?
compete with the substrate for
| the same active site
106
What do noncompetitive inhibitors do?
bind to the enzyme in a
| location other than the active site----changes shape of active site to prevent substrate from binding
107
What are allosteric sites
specific binding sites acting as on/off
switches
regulatory molecule binds to allosteric site to promote enzyme activity or does not bind to allosteric site to decrease enzyme activity
108
Do enzyme inhibitor bind to the enzyme?
yes
109
Do enzyme inhibitors decrease or increase enzyme activity?
decrease
110
What are the two confrontations for allosteric regulation?
high-affinity state (active form) and low -affinity state (inactive form)
111
First Law of Thermodynamics?
Energy can be transformed from one form to another, or transferred from one place to another, but it cannot be created or destroyed
112
Second Law of Thermodynamics?
The total disorder (entropy) of a system and its surroundings always increases (although the total energy in the universe does not change)
113
What is the First Law of Thermodynamic also referred to as?
principle of conservation of energy
114
What adds phosphate groups?
kinases
115
What removed phosphate groups?
phosphatases
116
As temperature rises, the rate of chemical reactions?
increases
117
Another name for optimal enzyme activity?
max enzyme activity---peak on graph
118
Why are the Siamese cat's extremities darker?
enzyme that makes the darker colored pigment are optimally active at that temperature (colder in the extremities)
119
What type of pH is pepsin optimally active?
acidic
120
Where would pepsin be found?
stomach acid
121
Amylase enzyme found in the mouth has a pH of what for optimal activity?
7
122
What type of pH is trypsin optimally active?
basic
123
What happens to enzymes at high temperatures?
they denature
124
Did the RNA or DNA world come first?
RNA
125
Did the RNA or DNA world come first?
RNA
126
What are Ribozymes?
group of RNA molecules that accelerate the rate of certain reactions without being changed by the reaction
127
What do ribozymes in ribosomes catalyze do?
catalyze the linkage of amino acids in protein synthesis
128
Does a ribozyme fit the definition of an enzyme?
yes
129
What catalyzes the cutting and splicing reaction s that remove excess segments from RNA molecules?
ribozymes
130
What does feedback inhibition do?
end product is a factor in the cycle/mechanism. Can have part of controlling the cycle
131
Do kinases activate or deactivate an enzyme?
they do both
132
What is the function of phosphatases?
reverse effects of phosphorylation done by kinases
133
What is the function of phosphatases?
reverse effects of phosphorylation done by kinases
134
How does an increasing temperature affect kinetic motion?
it increases kinetic motion to break hydrogen bonds
135
What are the two roles ribozyme played when cellular life first appeared?
enzymes and information molecules
