WEEK 4 PART 1 Flashcards
(147 cards)
1
Q
What will I learn about enzyme structure?
A
You’ll learn what enzymes are made of and how they’re built to do their job.
2
Q
What will I learn about enzyme catalysis?
A
You’ll learn how enzymes make chemical changes happen faster in your body.
3
Q
What will I learn about enzyme measurements?
A
You’ll learn how to measure enzyme speed using special math formulas.
4
Q
What will I learn about enzyme inhibitors?
A
You’ll learn how certain drugs can slow down or stop enzymes from working.
5
Q
What will I learn about enzyme inhibition strength?
A
You’ll learn how to measure how strongly a drug blocks an enzyme.
6
Q
What’s the first main topic we’ll study?
A
“What are enzymes?” - the basic introduction to these important helpers in your body.
7
Q
Why do drug companies study enzymes?
A
Because many medicines (28%) work by changing how enzymes behave.
8
Q
How many drugs work by affecting enzymes?
A
About 28% of all medicines target enzymes to treat diseases.
9
Q
What does it mean that enzymes are ‘catalysts’?
A
They speed up chemical reactions without getting used up themselves.
10
Q
How do enzymes affect chemical reactions?
A
They make them happen much faster than they would on their own.
11
Q
Why don’t enzymes get used up during reactions?
A
They help make the reaction happen but don’t become part of the final product.
12
Q
What’s a real-life example of enzymes working?
A
Enzymes in your stomach and intestines that break down food into smaller pieces.
13
Q
What material are most enzymes made from?
A
Most are made from proteins, which are chains of building blocks called amino acids.
14
Q
How big are enzymes compared to other molecules?
A
They range from somewhat small to very large molecular structures.
15
Q
Are all helper molecules in the body made of protein?
A
No, some helpers (enzymes) are made of RNA instead of protein.
16
Q
How does an enzyme create a place for reactions?
A
It has a special pocket (active site) where chemical changes can happen easier.
17
Q
Why is the enzyme environment important?
A
A water-free environment helps the right chemical connections form properly.
18
Q
How do enzymes help molecules react?
A
They hold molecules in exactly the right position so they can interact better.
19
Q
How do enzymes reduce energy needs?
A
They provide an easier path for reactions that normally need lots of energy.
20
Q
What special parts help enzymes do their job?
A
Special chemical groups that actively help break and form chemical bonds.
21
Q
What is the active site?
A
A special pocket in the enzyme where the chemical reaction takes place.
22
Q
How does the active site work like a lock and key?
A
The molecule that needs changing (substrate) fits into this pocket like a key in a lock.
23
Q
What is the ‘substrate’ in simple terms?
A
The starting material that the enzyme will change into something else.
24
Q
What do the letters in ‘E + S → ES → EP → E + P’ stand for?
A
Enzyme + Substrate → Enzyme-Substrate complex → Enzyme-Product → Enzyme + Product.
25
What are transition complexes?
The in-between stages when the reaction is partly done but not finished.
26
Why must enzymes be picky about what they work on?
So they only change the right molecules and don't mess up other important ones.
27
Why is it important that each enzyme does a specific job?
To keep all the body's chemical pathways working correctly without interference.
28
What is meant by 'hydrophobic hollow'?
A water-hating pocket on the enzyme where the reaction happens.
29
What are amino acid residues?
The building blocks that form the active site and help with chemical changes.
30
Why do active sites need to keep water out?
Water can break the weak connections between the enzyme and its target.
31
How does a water-free environment help reactions?
It can make certain reactions need less energy to happen.
32
What does the picture on this page show?
A simple drawing of an enzyme with its special reaction pocket shown.
33
What happens when an enzyme forms a complex with a substrate?
The enzyme holds the target molecule in exactly the right position for reaction.
34
What's the main difference between 'Lock and Key' and 'Induced Fit' ideas?
Lock and Key says the fit is already perfect; Induced Fit says the enzyme adjusts to fit better.
35
What does the Lock and Key model tell us about enzymes?
Enzymes are very picky about which molecules they work with.
36
What does the Induced Fit model tell us about enzymes?
Enzymes can change their shape a bit to work better with their targets.
37
What's shown in the diagram on this page?
Pictures that help explain how enzymes interact with their target molecules.
38
What enzyme shows the Lock and Key principle?
Dihydrofolate reductase, which has a pocket shaped to fit its target NADP+.
39
What makes a binding pocket 'complementary' to its target?
Its shape and electrical charges match the target molecule like puzzle pieces.
40
Is the fit between enzyme and target usually perfect?
No, it's rarely a perfect match in real life, even though simple models suggest it is.
41
What is hexokinase?
An enzyme shaped like a 'U' that changes shape when it grabs glucose.
42
How does hexokinase show the Induced Fit idea?
When glucose binds, hexokinase's shape changes as its ends move closer together.
43
What does the 3D picture on this page show?
Hexokinase changing its shape when glucose (colored red) binds to it.
44
What happens to the enzyme during Induced Fit?
It changes shape to create better connections with its target molecule.
45
What happens to chemical bonds in the target during Induced Fit?
They get stretched or strained, making them easier to break.
46
What are functional groups in enzyme-target binding?
Specific parts of molecules that form connections between enzyme and target.
47
What three types of bonds help enzymes grab their targets?
Ionic bonds (charge attractions), hydrogen bonds (hydrogen sharing), and weak surface attractions.
48
What does the diagram show about enzyme-target connections?
How different parts of the enzyme form different kinds of bonds with the target.
49
How does Induced Fit improve molecular connections?
It moves bonding groups to the perfect distance for strongest connections.
50
How does Induced Fit help break bonds?
It puts stress on certain bonds in the target, like stretching a rubber band.
51
What does the diagram show about enzyme shape changes?
How the enzyme moves to create better connections with its target.
52
How does pyruvic acid stick to the LDH enzyme?
Through different kinds of bonds including weak surface attractions and stronger connections.
53
What helps NADH work with LDH?
NADH provides electrons that help change pyruvic acid into lactic acid.
54
What job does LDH perform in the body?
It changes pyruvic acid into lactic acid with help from a helper molecule NADH.
55
What happens to NADH during the LDH reaction?
It changes to NAD+ after giving electrons to help make lactic acid.
56
What happens to pyruvic acid when LDH grabs it?
One of its chemical bonds gets weaker, making the molecule easier to change.
57
What does 'Enzyme-Substrate Complex' mean?
The temporary pairing formed when an enzyme grabs its target molecule.
58
What's the next big question about enzymes?
"How do enzymes make chemical reactions happen faster?" - their working methods.
59
What four ways do enzymes help reactions?
They provide a reaction site, position molecules correctly, lower energy needs, and use special chemical helpers.
60
What steps happen during enzyme catalysis?
Target binding, complex formation, chemical change, and product release.
61
How does lowering energy needs help reactions?
It makes reactions happen much faster than they would without the enzyme.
62
Why is understanding enzyme action important for making medicines?
It helps scientists create drugs that can control enzyme activity in sick people.
63
What makes chemical reactions hard to happen naturally?
Energy barriers, alignment problems, unstable charge changes, and bond shifting.
64
Why do molecules need extra energy for reactions?
To overcome the natural barriers that prevent reactions from happening easily.
65
What is a transition state?
A brief moment when bonds are partly broken and formed, at a 'chemical crossroads.'
66
How does activation energy affect reaction speed?
Higher energy barriers mean slower reactions because more energy is needed.
67
How do enzymes speed up reactions?
By lowering the energy hill that molecules must climb to react.
68
Do enzymes change what products are made?
No, they just make the reaction happen faster without changing the end result.
69
What is binding energy?
Energy released when the enzyme and target form many weak connections.
70
How does binding energy help reactions happen?
It provides energy that helps lower the barrier for the reaction.
71
What's another way enzymes help reactions?
They have special chemical groups that actively help break and form bonds.
72
What is acid-base catalysis?
When enzymes give or take hydrogen ions (protons) to help reactions happen.
73
What is covalent catalysis?
When enzymes form a temporary chemical bond with the target molecule.
74
What is metal ion catalysis?
When metal ions in the enzyme help move electrons or protons during the reaction.
75
What are nucleophilic groups?
Chemical groups like -OH or -SH that can attack other molecules during reactions.
76
How does acid-base catalysis prevent unstable molecules?
By giving or taking protons at just the right time to avoid problem molecules.
77
Why must enzymes work as both acids and bases?
To complete their job cycle, they must be able to both give and take protons.
78
Which protein building blocks often act as acids or bases?
Histidine, lysine, and arginine can all give and take protons during reactions.
79
What is a catalytic triad?
Three amino acids working together as a team to perform a specific reaction.
80
What three amino acids work together in chymotrypsin?
Serine (attacks bonds), histidine (moves protons), and aspartate (positions correctly).
81
How do the three amino acids in a catalytic triad cooperate?
Each does a specific job in breaking bonds and moving chemical pieces.
82
What enzyme works similarly to chymotrypsin?
Acetylcholinesterase also uses three amino acids working together.
83
How is acetylcholinesterase's working team different?
It uses glutamate instead of aspartate in its three-member team.
84
How do metal ions help position substrates?
They form coordinate bonds that hold the substrate in the right orientation.
85
How do metal ions help with electron transfer?
They can accept or donate electrons during oxidation-reduction reactions.
86
How do metal ions help keep enzymes in shape?
They form bonds that maintain the enzyme's correct 3D structure.
87
How many enzymes need metal helpers?
About one out of every three enzymes needs metal ions to work properly.
88
What's special about covalent catalysis?
It creates an actual chemical bond between the enzyme and target molecule.
89
What does 'Catalytic Mechanism' mean?
The different methods enzymes use to make chemical reactions happen faster.
90
What does 'Enzyme kinetics' refer to?
The study of how fast enzyme reactions happen and what affects their speed.
91
What does the Michaelis-Menten equation tell us?
How reaction speed relates to how much substrate is present (V = Vmax[S]/(Km+[S])).
92
What does Vmax mean in simple terms?
The top speed an enzyme can work when it has all the substrate it can handle.
93
What does Km mean in simple terms?
The amount of substrate needed for the enzyme to work at half its top speed.
94
Why doesn't the Michaelis-Menten model work for all enzymes?
Some enzymes behave differently and don't follow this mathematical pattern.
95
How does doubling enzyme amount affect reaction speed?
It doubles the reaction speed if there's plenty of substrate available.
96
What does 'reversible formation' mean for enzyme-substrate complexes?
The enzyme and substrate can form and break apart in a reversible manner.
97
What is Vmax in simple terms?
The top speed an enzyme can work when it has all the substrate it can handle.
98
What does 'reversible formation' mean for enzyme-substrate complexes?
The enzyme and substrate can join together and break apart multiple times.
99
What happens at very low substrate amounts?
Reaction speed increases directly with substrate (double substrate = double speed).
100
What happens at medium substrate amounts?
Speed increases but not in a direct relationship (relationship is changing).
101
What happens when there's tons of substrate?
Speed stops increasing because all enzyme molecules are already busy.
102
What does Km tell us about an enzyme's efficiency?
It shows how much substrate is needed for the enzyme to work at half its top speed.
103
How do you find Km using the Michaelis-Menten equation?
When reaction speed = ½Vmax, then substrate concentration = Km.
104
What do k1, k-1, and k2 represent?
Speed values for each step: forming complex, breaking complex, and making product.
105
What does k1 measure specifically?
How quickly enzyme and substrate come together to form a complex.
106
What does k-1 measure specifically?
How quickly the complex breaks apart back into enzyme and substrate.
107
What does k2 measure specifically?
How quickly the complex transforms into product and releases it.
108
What does 'steady state' mean for enzyme reactions?
The amount of enzyme-substrate complex stays the same during the reaction.
109
What is an enzyme's turnover number?
How many target molecules each enzyme can process each second.
110
How do you figure out the turnover number?
Divide maximum speed by enzyme amount: kcat = Vmax/[E].
111
What does a high turnover number tell us?
The enzyme works very efficiently and processes targets quickly.
112
What does catalytic efficiency (kcat/Km) tell us?
How well the enzyme works when substrate levels are low (real-world conditions).
113
What is a Lineweaver-Burk plot?
A graph that turns curved enzyme data into a straight line by plotting 1/V vs. 1/[S].
114
Why is this plot helpful for studying enzyme blockers?
Different types of blockers create different line patterns, making them easy to spot.
115
What does the y-intercept on this plot tell us?
1/Vmax - the inverse of the maximum reaction speed.
116
What does the slope on this plot tell us?
Km/Vmax - how the Michaelis constant relates to maximum speed.
117
Why use Lineweaver-Burk plots instead of regular plots?
Regular plots never truly reach maximum speed, making calculations less accurate.
118
What's the Lineweaver-Burk equation?
1/V = (Km/Vmax)(1/[S]) + 1/Vmax - a straight-line version of enzyme kinetics.
119
How do you find Vmax from a Lineweaver-Burk plot?
Take 1 divided by the y-intercept: Vmax = 1/(y-intercept).
120
How do you find Km from a Lineweaver-Burk plot?
Multiply the slope by Vmax: Km = slope × Vmax.
121
What does the equation Y = mX + b mean for enzyme plots?
1/V = (Km/Vmax)(1/[S]) + 1/Vmax - where m is slope and b is y-intercept.
122
How do you solve an enzyme kinetics problem?
Measure speeds at different substrate amounts, make a Lineweaver-Burk plot, and find values.
123
How do you prepare data for a Lineweaver-Burk plot?
Take 1 divided by each speed and 1 divided by each substrate amount.
124
What does the example equation y = 0.25x + 0.3337 tell us?
1/Vmax = 0.3337 and Km/Vmax = 0.25, letting us calculate Vmax and Km.
125
What important enzyme concepts do these pages summarize?
The main ways to measure and calculate enzyme speed and efficiency.
126
What four things can change how well an enzyme works?
Temperature, acidity (pH), helper molecules, and blocker molecules.
127
Why do enzymes care about temperature and pH?
Each enzyme works best at certain temperatures and acidity levels.
128
Why do extreme conditions hurt enzymes?
They can unfold the enzyme (like scrambling an egg), stopping it from working.
129
Why is this knowledge important for medicine?
It helps scientists control enzyme activity when designing treatments.
130
Why do enzymes from different sources like different temperatures?
They evolved to work in specific environments (like human body or hot springs).
131
What happens to enzyme activity as it gets warmer?
Activity increases to a point, then drops sharply as the enzyme starts to unfold.
132
Why are high fevers dangerous?
They can 'cook' important proteins in your body, including vital enzymes.
133
How does acidity (pH) affect enzyme activity?
It changes electrical charges on the enzyme and its target, affecting how they fit.
134
What pH do most human enzymes prefer?
Between pH 6-8, which is close to neutral (like blood).
135
What are cofactors?
Non-protein helpers that some enzymes need to do their job.
136
What's the difference between cofactors and coenzymes?
Cofactors include any helper; coenzymes are specifically organic (carbon-containing) helpers.
137
What metals commonly help enzymes?
Zinc, iron, copper, and other minerals that assist with enzyme function.
138
How do vitamins help enzymes?
Many vitamins become coenzymes that help enzymes do their job.
139
What are the main points about enzymes?
They're proteins that speed up reactions by binding targets at special sites.
140
How does shape-changing (induced fit) help enzymes?
It creates better connections between enzyme and target for more efficient reactions.
141
How do enzymes make reactions need less energy?
Through binding energy and special mechanisms that help the reaction along.
142
What methods do enzymes use to help reactions?
Acid-base (proton transfer), covalent bonding, and metal ion assistance.
143
What equation shows how enzyme speed relates to substrate amount?
V = Vmax[S]/(Km + [S]) - the Michaelis-Menten equation.
144
What's the basic enzyme reaction in simple form?
E + S ⇌ ES → E + P - enzyme grabs target, changes it, releases product.
145
What does Km tell about enzyme-substrate binding?
How much substrate is needed for half-speed and how strongly they bind.
146
What does kcat (turnover number) tell us?
How many target molecules each enzyme processes per second.
147
What does kcat/Km tell us about an enzyme's effectiveness?
How well it works overall, especially when substrate is limited.
