Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Bio > Chapter 3 > Flashcards

Chapter 3 Flashcards

(62 cards)

Start Studying
1
Q

Term/Front

A

Definition/Back

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

What is the primary function of enzymes in biochemical reactions?

A

Enzymes speed up biochemical reactions by lowering the activation energy required to initiate a given reaction.

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

What are enzymes?

A

Enzymes are organic (carbon-based) catalysts that bind to a molecule called substrate, which is the reactant undergoing an enzyme-facilitated reaction.

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

What is the active site of an enzyme?

A

The active site is a pocket-like area of the enzyme’s tertiary structure where the substrate binds.

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

What happens when an enzyme binds to its substrate?

A

When an enzyme binds to its substrate at the active site, they form an enzyme-substrate complex, and the active site undergoes a conformational change.

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

What is an enzyme-substrate complex?

A

An enzyme-substrate complex is the structure formed when an enzyme and substrate are bound together.

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

What is a conformational change in the context of enzymes?

A

A conformational change is a change in the 3D shape of macromolecules such as proteins, occurring when an enzyme binds to its substrate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is activation energy?

A

The initial amount of energy required for a chemical reaction.

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

What is the collision theory?

A

Molecules need to collide with enough kinetic energy to overcome the activation energy of the reaction.

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

What is an anabolic reaction?

A

A reaction where two or more smaller molecules combine to form a larger one, resulting in energy gain.

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

What is a catabolic reaction?

A

A reaction where a larger molecule breaks down into two or more smaller molecules, resulting in energy loss.

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

How do enzymes catalyse reactions?

A

Enzymes lower the activation energy of chemical reactions by bringing reactants closer to the state they need to be in to react.

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

What is a biochemical pathway?

A

A series of reactions where one enzyme catalyses a substrate into a product, often involving multiple enzymes working together.

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

What is a biochemical pathway?

A

A series of enzyme-catalysed biochemical reactions in which the product of one reaction becomes the substrate of the next reaction, also known as a metabolic pathway.

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

What role do enzymes play in biochemical reactions?

A

Enzymes are organic catalysts that lower the activation energy of reactions, are specific, not used up in reactions, and can sometimes work in both directions.

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

Can enzymes catalyse each step of metabolic pathways?

A

Yes, enzymes can catalyse each step of entire metabolic pathways.

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

What happens to an enzyme when the temperature exceeds its optimal range?

A

The enzyme can denature, causing a conformational change in its active site and making the substrate no longer fit.

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

What is the optimal temperature range for enzymes in the human body?

A

The optimal temperature range for enzymes in the human body is 36 - 38°C.

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

How does temperature affect the activity of enzymes?

A

As temperature increases, chemical reactions speed up due to greater kinetic energy, allowing enzymes and substrates to collide more frequently.

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

What occurs to enzymes when the temperature drops below the optimal level?

A

Enzymes move slower and collide less frequently, leading to little to no activity, but they can regain functionality when reheated.

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

What is meant by the term ‘tolerance range’ in relation to enzyme function?

A

The tolerance range refers to the wider range of conditions under which an enzyme can function, outside of which the enzyme is inactive.

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

What happens to enzyme activity as temperature rises towards its optimal temperature?

A

Enzyme activity increases due to higher kinetic energy, leading to more enzyme-substrate complexes.

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

What occurs to enzyme activity at temperatures approaching the lower limit of the tolerance range?

A

Enzyme activity slows down until freezing occurs, causing a reversible loss of function.

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

What is the effect of high temperatures on enzyme function?

A

Enzyme activity sharply declines until denaturation occurs, resulting in a complete and irreversible loss of function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How does pH affect enzyme activity?
Extreme pH levels can lead to denaturation of enzymes, affecting their function.
26
What is the optimal pH range for pepsin?
Pepsin functions optimally at a pH around 1.5 – 2.
27
What shape does the graph of enzyme activity against pH typically take?
It results in a symmetrical, bell-shaped curve due to denaturation at extreme pH values.
28
How does substrate concentration affect reaction rate when enzyme concentration is constant?
Increasing substrate concentration leads to an increase in the overall reaction rate.
29
What happens to the reaction rate when enzyme concentration remains constant and substrate concentration increases?
The reaction rate will increase because there are more reactants available to undergo the reaction.
30
What is the saturation point in enzyme-substrate interactions?
The saturation point occurs when all enzyme active sites are continuously occupied by substrate molecules, leading to maximum reaction rate.
31
What role does substrate concentration play before reaching the saturation point?
Before reaching the saturation point, substrate concentration acts as a limiting factor in the reaction.
32
How does enzyme concentration affect reaction rate?
Higher enzyme concentrations lead to higher reaction rates due to more available active sites for substrate binding.
33
What occurs graphically when enzyme concentration is increased while substrate concentration is constant?
The reaction rate increases until all available active sites are saturated, after which further increases in enzyme concentration do not affect the reaction rate.
34
In biological systems, how does enzyme concentration typically compare to substrate concentration?
Enzyme concentrations are typically lower than substrate concentrations, so increasing enzyme concentration usually increases the reaction rate.
35
What are competitive inhibitors and how do they affect enzyme activity?
Competitive inhibitors block the active site of an enzyme, preventing the substrate from binding and thus inhibiting the reaction.
36
How do non-competitive inhibitors function?
Non-competitive inhibitors bind to a site other than the active site, causing a conformational change that prevents the substrate from binding.
37
What distinguishes reversible inhibitors from irreversible inhibitors?
Reversible inhibitors bind weakly and can be removed, allowing the enzyme to regain activity, while irreversible inhibitors form strong bonds that cannot be broken.
38
What happens in reversible competitive inhibition?
In reversible competitive inhibition, the inhibitor forms weak bonds with the enzyme's active site, which can be overcome by increasing substrate concentration.
39
What is the effect of non-competitive reversible inhibitors on substrate concentration?
Non-competitive reversible inhibitors are not affected by substrate concentration and bind to a site other than the active site, altering the enzyme's shape and function.
40
What occurs during irreversible inhibition?
In irreversible inhibition, inhibitors form strong, unbreakable bonds with enzymes, preventing them from binding with substrates or catalyzing reactions indefinitely.
41
How do enzyme inhibitors regulate biochemical pathways?
Enzyme inhibitors control the production of specific products based on the body's requirements, disrupting pathways by inhibiting enzymes, which prevents overproduction.
42
What is the role of an inhibitor in a series of enzyme-catalyzed reactions?
An inhibitor can disrupt the pathway by non-competitively and reversibly inhibiting an enzyme, halting its function and regulating the production rate of final products.
43
What happens when Enzyme 1 is inhibited by the product of Enzyme 3?
The inhibition reduces the availability of Substrate 2 for the subsequent reaction catalyzed by Enzyme 2, thus regulating the production rate of the final product (Substrate 3).
44
What are self-regulating pathways?
Self-regulating pathways are those where the amount of product is controlled by the inhibition of enzymes, preventing overproduction within the biochemical pathway.
45
What are self-regulating pathways in enzymatic reactions?
Self-regulating pathways are those where the amount of product is controlled by one enzyme within the pathway, such as Enzyme 3. Inhibition of an earlier enzyme can lead to substrate accumulation, necessitating pathway recommencement.
46
What role do coenzymes play in enzymatic reactions?
Coenzymes assist enzymes in catalyzing reactions by binding to the active site, donating energy or molecules, and being recycled after the reaction.
47
How do coenzymes differ from cofactors?
Cofactors are molecules that assist enzyme functioning, while coenzymes are a subset of cofactors that are organic, non-protein molecules.
48
What happens to a coenzyme during an enzymatic reaction?
During the reaction, the coenzyme binds to the enzyme, donates energy or molecules, and then cannot be immediately reused. After the reaction, it leaves the enzyme and is recycled.
49
What is the significance of the cycling of coenzymes?
The cycling of coenzymes is integral to many biochemical processes, allowing them to assist in multiple reactions by being recycled after each reaction.
50
What is the primary function of adenosine triphosphate (ATP) in cells?
ATP serves as the primary energy unit in cells, donating energy for various reactions.
51
What happens to ATP during energy transfer?
ATP loses a phosphate group, becoming adenosine diphosphate (ADP).
52
How is ADP converted back to ATP?
ADP can be rephosphorylated to regenerate ATP, facilitating further energy transfer.
53
What is coenzyme cycling?
Coenzyme cycling refers to the continuous cycle of ATP and ADP conversion.
54
What distinguishes 'loaded' ATP from 'unloaded' ADP?
'Loaded' ATP carries three phosphate groups, while 'unloaded' ADP has only two phosphate groups.
55
How frequently do ATP molecules undergo coenzyme cycling?
ATP molecules are cycled between ADP and ATP over 1,000 times daily.
56
What effect does increasing substrate or enzyme concentration have on reaction rate?
An increase in substrate or enzyme concentration will increase reaction rate up to a certain point.
57
What is the difference between competitive and non-competitive inhibitors?
Competitive inhibitors block an enzyme’s active site, while non-competitive inhibitors bind elsewhere and alter the structure of the active site.
58
What is the difference between reversible and irreversible inhibitors?
Reversible inhibitors bind weakly and impair the enzyme temporarily, whereas irreversible inhibitors bind strongly and impair it permanently.
59
How do coenzymes differ from inhibitors?
Unlike inhibitors, coenzymes assist enzyme functioning and must be recycled after undergoing a reaction.
60
What is non-competitive inhibition?
Non-competitive inhibition is the hindrance of an enzyme by binding to an allosteric site and changing the shape of the active site to prevent the substrate from binding.
61
What is an allosteric site?
An allosteric site is a region on an enzyme that is not the active site.
62
Created on OmniSets
https://www.omnisets.com/set/250298/?open_edit_set=true

Bio (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions