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Flashcards in Respiration Deck (58):
1

Define Energy

The ability to do work

2

Define ATP

A phosphorylated nucleotide which is the universal energy currency

3

Define Anabolic Reactions

Reactions that are biochemical, where large molecules are synthesised from smaller ones

4

Define Catabolic Reactions

Reactions in which larger molecules are hydrolysed to produce smaller molecules

5

How does energy exist in the body?

Potential (stored) energy and Kinetic energy

6

What is energy measured in?

Joules and Kilojoules

7

What is a metabolism?

All the reactions within the body

8

Name metabolic reactions that need energy

Active Transport
Secretion
Endocytosis
Synthesis of large molecules
Replication of DNA
Movement
Activation of chemicals

9

Why is heat energy important for animals?

Because the body contains enzymes that work best at certain temperatures (usually very close to body temperature)

10

Where does the energy all species use originally come from?

The sun, and is converted by photoautotrophs through photosynthesis

11

Where does the energy all species use originally come from?

The sun, and is converted by photoautotrophs through photosynthesis

12

What does ATP stand for?

Adenosine Triphosphate

13

Draw the structure of an ATP molecule

Pg 81 in text book

14

What are the molcules produced by the hydrolysis of water?

ATP + H2O -> ADP + H2O -> AMP + H2O -> Adenosine

15

How much ATP is used by the human body every day?

25-50 kg, however 5g is only present at any time

16

How much energy is release from the hydrolysis of ATP?

30.6kJ for the first two reactions, 14.2kJ for the last

17

Define Oxidation Reactions

Reactions that involve the loss of electrons

18

Define Reduction Reactions

Reactions that involve the gain of electrons

19

What are the 4 stages of the respiration of glucose?

Glycolysis
The Link Reaction
The Krebs Cycle
Oxidative Phosphorylation

20

What happens to the stages of respiration under anaerobic conditions?

Glycolysis happens nomally however then lactate fermentation/ethanol fermentation takes place

21

What is NAD used for?

Helps dehydrogenase enzymes carry out oxidation reactions. It is used in all stages of respiration except oxidation phosphorylation

22

Define Glycolysis

A metabolic pathway where each glucose molecule is broken down to two molecules of pyruvate. It occurs in the cytoplasm of all living cells and is common in anaerobic and aerobic respiration.

23

Define Hexose Sugars

Sugars that have six carbon atoms in each molecule

24

Define Hydrolysis

The breaking down of large molecules to smaller molecules by the addition of water

25

Define Triose Sugars

Sugars that have 3 carbon atoms in each molecule

26

Draw the step by step reaction pathway of glycolysis

pg 84

27

What is the net gain of ATP molecules from glycolysis?

2 (2 used and 4 made)

28

What are the overall products of glycolysis

2ATP
2 reduced NAD
2 Pyruvate

29

What are the overall products of glycolysis

2ATP
2 reduced NAD
2 Pyruvate

30

Define Mitochondria

Organelles found in eukaryote cells. They are the sites of the link reaction, krebs cycle and oxidative phosphorylation- the aerobic stages of respiration.

31

What is the site for glycolysis

The cytoplasm of the cell

32

How big is a mitochondria

Between 0.5-1.0μm in diameter
Between 2-5μm in length
Some can be up to 10 μm, for example, athletes are likely to have larger mitochondria is their muscle cells

33

What is the mitochondrial envelope and what makes it up?

It is the membrane around the organelle made up of two phospholipid bilayers (the inner and the outer)

34

What is the space between the inner and outer mitochondrial membranes?

The intermembrane space

35

What is special about the inner mitochondrial membrane?

It is folded into cristae so that it has a large surface area

36

What is enclosed by the inner mitochondrial membrane?

The matrix

37

What is the matrix made up of?

It is a semi-rigid, gel like mixture, consisting of mainly proteins and lipids. It also contains looped mitochondrial DNA, mitochondrial ribosomes and and enzymes.

38

What features do mitochondria have in active areas of the body?

the mitochondria will likely be larger, with a more densely packed cristae, so that there are more electron transport chains, and more ATP synthase enzymes.

39

How do mitochondria move around?

It they need to be moved to a certain position, they are moved by microtubules on the outside of the organelle.

40

What reactions occur in the matrix?

The link reaction and the krebs cycle

41

What features does the matrix have for it to carry out it's function?

Enzymes to catalyse the link reaction and the krebs cycle.
Molecules of Coenzyme NAD.
Oxaloacetate
Mitochondrial DNA which codes for the enzymes and proteins present
Mitochondrial ribosomes to assemble the proteins.

42

What is the difference between the inner membrane and the outer membrane

The inner membrane has a different composition and is impermeable to most small ions.
Is folded into many cristae to give it a large surface area.
Has many electron carriers and ATP synthase embedded in it.

43

What is the structure of the electron carriers?

They are enzymes each associated with a cofactor which are non-protein groups. These are heam groups and contain an iron atom.

44

How are the cofactors able to accept and donate electrons?

The iron within the group can be reduced to Fe2+ (accepting) and oxidised to Fe3+ (donating).

45

What type of enzymes are the haem group with an iron atom?

They are oxidoreductase enzymes

46

What is the structure of ATP synthase?

Large enzymes that protrude from the inner membrane to the matrix.
Also known as stalked particles.
Allows protons to pass through them.

47

What is chemiosmosis?

The movement of H+ ions from a high concentration to a low concentration through a membrane.

48

Define the Link Reaction

A reaction that converts pyruvate to acetate and reduces NAD.

49

Define the Krebs Cycle

A reaction that oxidises acetate to carbon dioxide, reducing NAD and FAD and creates ATP through substrate level phosphorylation.

50

Draw a diagram of the link reaction and the krebs cycle

Pg 88, Fig.1

51

What removes hydrogen from pyruvate in the link reaction?

Pyruvate dehydrogenase

52

What removes the carboxyl group from pyruvate?

Pyruvate decarboxylate

53

Write an overall reaction for the link reaction

pyruvate + NAD+ + CoA -> CO2 + reduced NAD + acetyl CoA

54

What are the products of the link reaction per glucose molecule?

2 reduced NAD
2 Carbon Dioxide
2 acetyl CoA

55

What are the products of the krebs cycle per glucose molecule?

6 Reduced NAD
2 Reduced FAD
4 CO2
2 ATP

56

Define Oxidative Phosphorylation

The formation of ATP by adding a phosphate group to ADP, in the presence of oxygen, which is the final electron acceptor.

57

Draw a diagram of oxidative phosphorylation

Pg 90 Fig. 1

58

What is the final electron acceptor for respiration?

Oxygen
02 + 4H+ + 4e- --> 2H2O