Brainscape's Knowledge GenomeTM

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


See full index

BIO 110 > Chapter Nine > Flashcards

Chapter Nine Flashcards

1
Q

What are the principles of metabolic pathways?

A
  1. Complex transformations occur in a series of separate reactions
  2. Each reaction is catalyzed by a specific enzyme
  3. Many metabolic pathways are similar in all organisms
  4. In Eukaryotes are compartmentalized in specific organelles
  5. Key enzymes can be inhibited or activated to alter the rate of the pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the general reaction, the reactants, and products in the burning/metabolism of glucose?

A

C6H12O6 + 6O2 –> 6CO2 + 6H20 + free energy

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

Is the burning/metabolism of glucose endergonic or exergonic, and what is the net delta G + or -?

A

it is highly exergonic and the net delta G is -686 kcal/mol

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

What does the burning/metabolism of glucose drive?

A

it drives the endergonic formation of many ATP molecules.

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

What is an oxidation/reduction (redox) reaction?

A

when electrons are transferred between two molecules in a reaction

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

What happens when something is reduced or oxidized?

A

when something is reduced it gains an electron

when something is oxidized, it loses its electron

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

What is the agent that reduces and what is the agent that oxidizes?

A

the agent that reduces is the molecule that loses it electron, SINCE it is the reason the other molecule is reduced

the agent that oxidizes is the molecule that gains electron SINCE it is the reason the other molecule lost its electron.

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

The transfer of electrons is often associated with?

A

the transfer of hydrogen ions

a hydrogen atom is H+ ion plus a negatively charged electron

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

When a molecule loses H atoms what does it mean?

A

it becomes more oxidized

less hydrogens = more oxidized = less free energy

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

What is NADH, FADH2, and NADPH?

A

they are key coenzyme electron carriers in redox reactions

NADH = nicotinamide adenine dinucleotide

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

What is the oxidized form of NADH, and how many electrons / protons does the molecule transfer?

A

the oxidized form is NAD+ and it transfers 2 electrons and one proton (H+)

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

When NADH loses an electron to O2, which is oxidized and which is reduced? Is this exergonic or endergonic?
{NADH + (H+) + O2 –> (NAD+) + H2O}

A

The oxygen is reduced and the NADH is oxidized.

This reaction is exergonic because the NADH loses an electron and therefore releases energy.

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

What are the five energy-yielding metabolic pathways?

A
  1. Glycolysis
  2. Fermentation
  3. Pyruvate Oxidation
  4. Citric acid cycle or Krebs cycle
  5. Respiratory chain / ATP synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where does glycolysis occur and does it occur when oxygen is present or in the absence?

A

glycolysis occurs in the cytoplasm (cytosol) of the cell outside the mitochondria

glycolysis is anaerobic (it does not require oxygen), but functions the same even if oxygen is available

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

Where does fermentation occur and does it function with or without the presence of oxygen?

A

fermentation occurs in the cytoplasm

it occurs in the absence of oxygen

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

Where does pyruvate oxidation occur and does it function with or without the presence of oxygen?

A

it occurs in the mitochondrial matrix

it ONLY functions in the presence of oxygen.

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

Where does the citric acid cycle occur and does it function with or without the presence of oxygen?

A

it occurs in the mitochondrial matrix

it ONLY functions in the presence of oxygen

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

Where does the electron transport cycle / respiratory chain occur and does it function with or without the presence of oxygen?

A

it occurs in / through the inner membrane of the mitochondrial matrix - why the cristae has folds

it ONLY functions with the presence of oxygen

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

What does aerobic respiration mean?

A

it requires oxygen (ADD AFTER DISCUSSION)

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

What does anaerobic respiration mean?

A

it doesn’t require oxygen (ADD AFTER DISCUSSION)

21
Q

Define glycolysis and explain.

A

it is separate from cellular respiration, but is required to perform cell respiration

catabolic process that converts glucose into 2 pyruvate molecules

involves energy investment phase (1-5)
involves energy payoff phase (6-10)

22
Q

What are the input / output of glycolysis?

A

Input: 2 ATP, 2 NAD+, 1 Glucose (6 carbon), 2 Pi

Output 4 ATP, 2 NADH, 2 Pyruvate (3 carbon)

Net yield: 2 ATP, 2 NADH, 2 Pyruvate

23
Q

Where are glycolysis’ products used, i.e how is it connected to the other pathways?

A

The 2 NADH produced are used down the line in the ETC

The 2 Pyruvate are the input for the next pathway, pyruvate oxidation

Without glycolysis, no other pathway has a chance.

24
Q

Every pathway requires many specific (…….)

A

all of the reactions inside each pathways have their own specific enzyme that catalyses

25
Q

What are the inputs and outputs of pyruvate oxidation?

A

Inputs: 2 pyruvate, 2 NAD+ 2 Coenzyme A

Outputs: 2 Acetyl CoA (2 carbon), 2 NADH, 2 CO2

26
Q

Where are the products of pyruvate oxidation used, i.e how is it connected to other pathways?

A

The CO2 is released outside of the cell

The acetyl CoA is used in the citric acid cycle

The 2 NADH are used later in the ETC

27
Q

What are the inputs and outputs of the krebs cycle?

A

Inputs: 2 Acetyl CoA, 6 NAD+, 2 FAD, 2 ADP, and 2P(i) water

Outputs 4 CO2, 2 ATP, 6 NADH, 2 FADH2

28
Q

Where are the products of the krebs cycle used, i.e how it is connected to other pathways?

A

The CO2 is released

The NADH, and FADH2 are used in the ETC

The krebs cycle relies on pyruvate oxidation to provide the acetyl CoA

29
Q

What are the inputs and outputs of oxidative phosphorylation (ETC + ATP synthesis)?

A

Inputs: 10 NADH, 2 FADH2, H+, 28 ADP, Pi

Outputs: 10 NAD+, 2 FAD, H2O, 28 ATP

30
Q

Where are the products of oxidative phosphorylation used, i.e how is it connected to other pathways and the cell at large?

A

Of the 10 NAD+ 2 are used back in glycolysis, 2 back in pyruvate oxidation, and 6 in the krebs cycle

The 2 FAD are used in the krebs cycle

The water is used for its presence of H+ to be pumped back into the inter-membrane space

31
Q

How else is oxidation phosphorylation connected to the rest of the pathways, specifically the last step of the ETC?

A

For the first three pathways in aerobic respiration to continue, NADH must be oxidized again, and FADH2 must as well.

Since they donate their electrons to O2, if oxygen is low, they can’t donate them and the “aerobic” pathway gets backed up

32
Q

What is oxidative phosphorylation?

A

When NADH and FADH2, in the presence of O2 are oxidized and their electrons are used during a series of steps to synthesize ATP

33
Q

What is the electron transport cycle?

A

when the electrons from NADH and FADH2 pass through a series of protein complexes inside the inner membrane

the electrons flow results in a (high potential energy) proton concentration gradient across the membrane

(inner-membrane space high and mitochondrial matrix low)

34
Q

What is chemiosmosis?

A

when protons naturally flow back across the membrane through a channel protein ATP synthase (uniporter) (facilitated diffusion) which couples this diffusion with ATP synthase

35
Q

What happens to the free energy of the (system?) electron carriers as the ETC progresses?

A

The free energy goes down because the electron carriers are oxidized and the energy of the electrons is being used to pump the H+ into the inter-membrane space.

36
Q

Explain the role of potential energy in the ETC and chemiosmosis.

A

the carrier protein complexes use the potential energy of the electrons to move the H+ ions

once the ions have been translocated, the hydrogen ions then move through ATP synthase for two reasons

  1. The difference in chemical potential
  2. The electrical potential due to the charge difference
37
Q

Where do the electrons that are responsible for pumping H+ ions into the inter-membrane space come from?

A

In complex 1 they come from NADH

In complex 2 they come from FADH2

38
Q

What is the importance of the proton/ H+ gradient?

A

If a concentration gradient doesn’t exist between the matrix and inter-membrane space that allows for facilitated, passive transport of ions (energy is in the gradient) - that power the synthesis of ATP, the cell will quickly become starved of energy

39
Q

What is the proton motor force?

A

the force generated across a membrane that has two components:

a chemical potential (difference in proton concentration)

a electric potential due to the + charge on the proton

40
Q

What is the final electron acceptor?

A

Oxygen is the final electron acceptor, when the electrons are donated to an oxygen atom

41
Q

What is fermentation and is it aerobic or anaerobic?

A

similar to cellular respiration, fermentation also breaks down glucose in order to harvest chemical energy

However it is different than cell respiration in that it does not use oxygen

42
Q

What the two types of fermentation?

A

Lactic Acid

Alcoholic

43
Q

Explain glycolysis and lactic acid fermentation.

A

It occurs in microorganisms and some vertebrate muscle cells - PYRUVATE IS FINAL ELECTRON ACCEPTOR
key enzyme is lactate dehydrogenase

Input is Glucose, 2 ADP, 2 Pi, 2 NAD+

Output is 2 lactate, 2 NAD+, 2 ATP

44
Q

Explain glycolysis and alcoholic fermentation.

A

It occurs in yeasts and some plant cells - PYRUVATE IS THE FINAL ELECTRON ACCEPTOR
two enzymes are required

Input is Glucose, 2 ADP, 2 Pi, 2 NAD+

Output is 2 ethanol, 2 ATP, 2 CO2, 2 NAD+

45
Q

Give examples of Catabolic interconversions.

A
  1. Polysaccharides are hydrolyzed to glucose which enters glycolysis
  2. Lipids broken down - glycerol broken down and enters glycolysis
  3. Fatty acids are broken down and enter the citric acid cycle
  4. Proteins hydrolyzed to amino acids which feed into glycolysis or citric acid cycle
46
Q

What is glycogenesis?

A

it is glucose formed from citric acid cycle and glycolysis intermediates

47
Q

How are metabolic pathways regulated?

A
  1. change amount of active enzyme by regulating gene expression
  2. Change enzyme activity by covalent modifications (phosphorylation)
  3. Feedback inhibition by allosteric enzymes
48
Q

If an abundance of oxygen is available what happens to the enzyme that regulates glycolysis?

A

the enzyme is inhibited

BIO 110 (19 decks)

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