Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology 120 > Cellular Respiration > Flashcards

Cellular Respiration Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is the main purpose of cellular respiration?

A

To break down food molecules to produce ATP

Cellular respiration includes catabolic reactions.

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

What is the key equation for cellular respiration?

A

C6H12O6 + 6O2 → 6CO2 + 6H2O + Chemical Energy (ATP)

This equation summarizes the overall process of cellular respiration.

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

Where does energy originate in the context of cellular respiration?

A

From the Sun, captured via photosynthesis

Energy is stored in sugars.

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

How is energy in glucose harnessed during cellular respiration?

A

By transferring electrons through a series of redox reactions

This process powers ATP synthesis.

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

What are the three main stages of cellular respiration?

A
  1. Glycolysis
  2. Pyruvate Oxidation and Citric Acid Cycle
  3. Oxidative Phosphorylation

Each stage has distinct processes and occurs in different cellular locations.

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

Where does glycolysis occur?

A

In the cytosol

Glycolysis converts glucose into two pyruvate molecules.

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

What are the products of glycolysis?

A

2 ATP (net) and 2 NADH

Glycolysis is an anaerobic process.

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

What happens during pyruvate oxidation?

A

Pyruvate is converted into Acetyl-CoA

This occurs in the mitochondrial matrix.

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

What does Acetyl-CoA enter after pyruvate oxidation?

A

The citric acid cycle (Kreb’s Cycle)

This cycle produces NADH, FADH2, ATP, and CO2.

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

What is oxidative phosphorylation?

A

Involves the electron transport chain (ETC) and chemiosmosis

It is the final stage of cellular respiration.

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

What role do NADH and FADH2 play in oxidative phosphorylation?

A

They provide high-energy electrons to the electron transport chain

This process creates an electrochemical gradient.

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

What is chemiosmosis?

A

The movement of H+ down their concentration gradient through ATP synthase

This movement powers ATP production.

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

Who is the terminal electron acceptor in cellular respiration?

A

O2

It becomes reduced to H2O.

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

Fill in the blank: Glycolysis converts glucose into _______.

A

two pyruvate molecules

Each pyruvate molecule has 3 carbons.

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

True or False: Glycolysis can occur in the absence of oxygen.

A

True

This is why it is classified as an anaerobic process.

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

What are the two mechanisms of ATP production?

A
  1. Substrate-level phosphorylation
  2. Oxidative phosphorylation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define substrate-level phosphorylation.

A

Direct transfer of phosphate to ADP

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

What is oxidative phosphorylation?

A

ATP synthase uses energy from the proton gradient

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

Which mechanism produces the most ATP?

A

Oxidative phosphorylation

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

What is the Electron Transport Chain (ETC)?

A

A series of protein complexes and mobile electron carriers involved in oxidative phosphorylation during cellular respiration

Occurs in the inner mitochondrial membrane in eukaryotes and the plasma membrane in prokaryotes.

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

What are the primary electron sources for the ETC?

A

Electrons harvested from glucose during glycolysis, pyruvate oxidation, and the citric acid cycle, carried by NADH and FADH2

NADH and FADH2 are oxidized back to NAD* and FAD.

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

What happens to NAD* and FAD after donating their electrons?

A

They are recycled back to glycolysis and the citric acid cycle to get reduced and repeat the cycle.

23
Q

What are the key components of the ETC?

A

Complexes I, II, III, IV

These complexes facilitate the movement of electrons via redox reactions.

24
Q

How do electrons move through the ETC?

A

Via a series of redox reactions through protein complexes, with each complex having a higher affinity for electrons than the previous one.

25
Q

What happens to the energy of electrons as they move down the ETC?

A

They lose free energy, which is used to pump protons (H+) across the inner mitochondrial membrane.

26
Q

What is created as a result of protons being pumped across the inner mitochondrial membrane?

A

An electrochemical gradient, known as the proton motive force.

27
Q

What is the role of oxygen in the ETC?

A

It accepts electrons and combines with H* ions to form water (H2O), acting as the terminal electron acceptor.

28
Q

What would happen to the ETC without oxygen?

A

The chain cannot operate, halting ATP production.

29
Q

Fill in the blank: The energy released as electrons flow is used by Complexes I, III, and IV to pump _______ ions.

A

H+

30
Q

What two types of potentials contribute to the proton motive force?

A

Chemical Potential and Electrical Potential

Chemical potential refers to the high concentration of H+ in the intermembrane space, while electrical potential refers to the positive charge in the intermembrane space relative to the matrix.

31
Q

True or False: The electrons start at a very low energy level when they are associated with NADH or FADH2.

A

False

32
Q

What happens to electrons by the time they reach the terminal electron acceptor?

A

They are at a very low energy level.

33
Q

What drives the rotation of ATP synthase?

A

Protons flow back into the matrix through ATP synthase

This flow of H+ acts like a turbine, enabling ATP synthesis.

34
Q

What is the primary function of ATP synthase?

A

Catalyzes the phosphorylation of ADP to ATP

ATP synthase converts ADP into ATP using the energy from the proton gradient.

35
Q

Which electron carrier contributes more energy to proton pumping?

A

NADH

NADH enters the electron transport chain at Complex I, while FADH2 enters at Complex II.

36
Q

At which complex does FADH2 enter the electron transport chain?

A

Complex II

FADH2 contributes less energy compared to NADH due to its entry point.

37
Q

What ensures efficient energy capture in the electron transport chain?

A

The gradual energy drop of electrons

This process minimizes excessive heat loss during energy transfer.

38
Q

What are the key molecules involved in respiration?

A
  • NADH
  • FADH2
  • ATP Synthase

NADH and FADH2 shuttle high-energy electrons, while ATP synthase generates ATP.

39
Q

What process allows ATP synthase to generate ATP?

A

Passive flow of H+ ions down their concentration gradient

This process utilizes the free energy released during the flow.

40
Q

What is feedback inhibition in the context of respiration?

A

Products of the pathway inhibit upstream enzymes, ensuring regulation based on cellular energy needs.

41
Q

What is lactate fermentation?

A

Produces lactic acid (in animals and some bacteria).

42
Q

What is alcoholic fermentation?

A

Produces ethanol and CO2 (in yeast).

43
Q

What is the primary reason fermentation exists?

A

To recycle NAD+ molecules.

44
Q

Why does NADH accumulate in the absence of oxygen?

A

Because NADH can’t donate its electrons to the ETC.

45
Q

What happens to NAD+ in the absence of oxygen?

A

NAD+ molecules become depleted, preventing glycolysis and the citric acid cycle from proceeding.

46
Q

What is the end result of depleted NAD+ during respiration?

A

No ATP production.

47
Q

Where does respiration occur in prokaryotes?

A

In the cytoplasm and plasma membrane.

48
Q

What are the types of organisms based on their oxygen requirements?

A

Strict aerobes, strict anaerobes, and facultative anaerobes.

49
Q

Fill in the blank: Fermentation is an alternative pathway when _______ is unavailable.

A

oxygen

50
Q

What are Reactive Oxygen Species (ROS)?

A

Byproducts of aerobic respiration that can damage cells

ROS are harmful and require management by the cell’s antioxidant systems.

51
Q

How are Reactive Oxygen Species (ROS) managed in cells?

A

Managed by antioxidant systems like enzymes (e.g., catalase)

Antioxidant systems help neutralize ROS to prevent cellular damage.

52
Q

True or False: Anaerobic prokaryotes cannot use oxidative phosphorylation.

A

False

Some anaerobic prokaryotes use molecules other than O2 as the terminal electron acceptor.

53
Q

Fill in the blank: Some anaerobic prokaryotes are able to use oxidative phosphorylation because they use _______ as the terminal electron acceptor.

A

[molecules other than O2]

Biology 120 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions