Biology > Respiration > Flashcards

Respiration Flashcards

(34 cards)

Study These Flashcards
1
Q

Why do organisms need energy?

A
  • active transport
  • endocytosis
  • exocytosis
  • DNA replication
  • Cell division
  • synthesis of proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where does glycolysis occur?

A

In the cytoplasm

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

What are the 3 main stages of glycolysis?

A
  1. phosphorylation of glucose –> hexose bisphosphate
  2. Splitting of HB into two triose phosphate molecules
  3. Oxidation of TP to pyruvate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does NADH do in aerobic respiration?

A
  • carries the protons and electrons to the cristae and delivers them to be used in oxidative phosphorylation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the products of glycolysis?

A
  • 2x ATP
  • 2x NADH
  • 2x pyruvate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the stages of respiration (in order)?

A
  1. glycolysis
  2. the link reaction
  3. the krebs cycle
  4. oxidative phosphorylation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is different about the last 3 stages of respiration?

A
  • only take place under aerobic conditions, pyruvate are AT to the mitochondria for the link reaction
  • in the absence of oxygen pyrcuvate is converted in the cytoplasm into lactate or ethanol (fermentation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the structure of the mitochondria and its functions

A
  1. Double membrane forms an envelope
    - Outer is smooth, inner is folded into cristae which increases SA and the site of the ETC
  2. Protein channels associated with ATP synthase allowing protons to diffuse through
  3. Mitochondrial matrix is gel like, contains mitochondrial ribosomes, looped DNA and enzymes used in respiration
  4. Intermembrane space= close to matrix, NADH and FADH can easily deliver hydrogens to ETC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the structure and function of electron transport proteins

A
  • Contains a cofactor (non protein haem group that contains an iron ion)
  • Iron ion can accept and donate electrons because it can become reduced (Fe2+) and oxidised (Fe3+)
  • they are oxido-reductase enzymes
  • have a coenzyme which pumps protons from the matrix to the intermembrane space used by ATP synthase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the link reaction produce?

A
  • 2x NADH
  • 2x CO2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the Krebs cycle produce?

A
  • 6x NADH
  • 2x FADH
  • 4x CO2
  • 2x ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What other substrates can be respired aerobically?

A
  • Fatty acids which are broken down into molecules of acetate that enter the Krebs cycle via CoA
  • Glycerol is converted to pyruvate and enters Krebs cycle by Link reaction
  • Amino acids are deaminated and the rest of the molecule can enter the Krebs cycle directly or be changed to pyruvate/ CoA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens if oxygen is absent in respiration?

A
  1. Oxygen cannot act as the final e- acceptor, protons diffusing through ATP synthase channels are not able to combine with electrons and oxygen to form water
  2. Conc of protons increase in matrix and reduces the gradient across the inner mito membrane
  3. oxidative phosphorylation ceases
  4. NADH and FADH are not able to unload their H+ atoms and cannot be reoxidised
  5. Krebs and link stop
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is it important that NADH generated during glycolysis is reoxidised?

A
  • the NADH egenrated in the oxidation of TP to pyruvate has to be reoxidised to continue glycolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is NADH reoxidised in eukaryotic cells?

A
  1. Fungi use the ethanol fermentation pathway
  2. Mammals use the lactate fermentation pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the process of ethanol fermentation

Study These Flashcards
A
  1. Each pyruvate is decarboxylated and converted to ethanal which is catalysed by pyruvate decarboxylase
  2. Ethanal accepts H+ atoms from NADH, reducing it to ethanol which is catalysed by ethanol dehydrogenase
  3. NADH is reoxidised and accepts more H+ from TP, allowing glycolysis to continue
17
Q

Describe the method of lactate fermentation

Study These Flashcards
A
  1. Pyruvate accepts H+ atoms from NADH catalysed by lactate dehydrogenase
  2. Causes pyruvate to be reduced to lactate and NADH is reoxidised
  3. Reoxidised NAD can accept more H+ atoms from TP during glycolysis
  4. Glycolysis can continue to produce enough ATP to sustain muscle contraction only for a short period of time
18
Q

What happens to lactate when more oxygen becomes available?

Study These Flashcards
A
  1. It is converted to pyruvate which enters the Krebs cycle via the link reaction
  2. It is recycled to glucose and glycogen
19
Q

Name 3 respiratory substrates

Study These Flashcards
A
  1. Carbohydrates
  2. Lipids
  3. Proteins
20
Q

How are carbohydrates used in respiration?

Study These Flashcards
A
  • Disaccharides can be digested to monosaccharides for respiration
  • Monosaccharides like fructose and galactose can be changed by isomerase enzymes to glucose for respiration
  • Carbhoydrates can be stored by animals and some bacteria as glycogen which can be hydrolysed to glucose
21
Q

Describe what happens to fatty acids for respiration?

Study These Flashcards
A
  1. Using energy from the hydrolysis of ATP, fatty acids are combined with CoA
  2. The FA-CoA complex is transported into the mito matrix where its broken down into 2c acetyl groups
  3. This generates NADH and FADH
  4. acteyl groups are released from CoA and enter krebs cycle by combining with the 4c oxaloacetate
22
Q

How are proteins used as a respiratory substrate?

Study These Flashcards
A
  • Excess amino acids released after the digestion of proteins are deaminated in the liver
  • the rest of the AA molecule, a keto acid, enters the respiratory pathway as pyruvate, acetyl CoA or oxaloacetic acid
23
Q

State the equation for respiratory quotient

Study These Flashcards
A

RQ= CO2 produced / O2 consumed

24
Q

Describe a brief method investigating factors affecting respiration

Study These Flashcards
A
  1. Place a coloured liquid (e.g methylene blue) containing a drop of detergent into the manometer tube
  2. Connect the apparatus with the taps open to allow air in the atmosphere to connect with the apparatus
  3. Measure the mass of the living organisms
  4. Place in a water bath for 10 minutes still with taps open
  5. Mark the level of coloured liquid in the manometer tube
  6. close taps, leave in water bath for a period of time
  7. change in manometer can be measured, syringe barrel depressed to reset the apparatus. this means you can also measure the amount of O2 absorbed
  8. Calculate volume of O2 absorbed per minute
25
How can we measure the effect of temperature on respiration?
- take three readings at each temperature - in between each, the apparatus and organisms should be allowed to adjust to the new temperature
26
Name the 4 stages of aerobic respiration and where they happen
1. Glycolysis: cytoplasm 2. Link reaction: mitochondrial matrix 3. Krebs cycle: mitochondrial matrix 4. Oxidative phosphorylation: ETC/ membrane of cristae
27
Outline the stages of glycolysis
Phosphorylation (phosphate), Lysis, Phosphorylation (ion), Dehydrogenation and formation
28
Outline stages of the link reaction
Pyruvate undergoes oxidative phosphorylation NAD is reduced 2c Acetyl group binds to coA to form acteylcoenzyme A
29
What happens in the Krebs cycle?
Acteyl group from coA combines with oxaloacetate Citrate is decarboxylated and dehydrogenated Lots of further decarboxylation and dehydrogenation Binding temporarily to CoA Substrate level phosphorylation Rearrangement to form oxaloacetate
30
State the role of oxygen in aerobic respiration
Final electron acceptor in e- transfer chain, the ETC cannot operate unless O2 is present
31
What are benefits of respiring anaerobically?
- ATP production continues - Production of ethanol/ lactate converts NADH back into NAD so glycolysis can continue
32
How could a student calculate the rate of respiration using a respirometer?
Volume= distance moved by coloured drop x (0.5 x capillary tube diameter)^2 x Pi Volume O2 produced or CO2 consumed / time x mass of sample
33
Why do respiratory substrates have different energy values?
It depends on the number of hydrogens in the structure which are oxidised to water
34
Outline the steps in oxidative phosphorylation
Transferring e- to the ETC Reduction and oxidation of ETC proteins Pump protons Water formation at the end of the ETC Terminal acceptor Concentration gradient Chemiosmosis
Biology
flashcards
Decks in class (24)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions