Chapter 12 energy and respiration

Question 1

Define respiration

Answer 1

The enzymatic release of energy from organic compounds in living things

Question 2

Define anabolic reaction

Answer 2

A chemical reaction in which smaller molecules are built up into larger ones

Question 3

Why ATP makes the perfect energy currency?

Answer 3

-the hydrolysis of ATP can be done quickly and easily, in whichever part of the cell the energy is required
-the hydrolysis of one molecule of ATP can release a useful quantity of energy, enough to fuel an energy requiring process in a cell and not so much is wasted
-ATP is a relatively stable molecule in a range of pH that normally occurs in the cell, it doesn’t break down unless the catalyst ATPase enzyme is present.

Question 4

How much KJ/mol is released from the removal of phosphate from ATP,ADP,AMP and how and why is it removed

Answer 4

-ATP: 30.5KJ/mol
-ADP: 30.5KJ/mol
-AMP: 14.2KJ/mol
It is removed by hydrolysis to release energy

Question 5

What are the two main ways in which ATP is made by ADP and a phosphate group

Answer 5

-substrate linked phosphorylation
-chemiosmosis

Question 6

Define substrate linked phosphorylation

Answer 6

The transfer of phosphate from a substrate molecule directly to a ADP to produce ATP, using energy provided by other chemical reaction

Question 7

Define chemiosmosis

Answer 7

The synthesis of ATP using energy released by the movement of hydrogen ions down their concentration gradient, across a membrane in a mitochondria and chloroplast

Question 8

Define glycolysis

Answer 8

Lysis of glucose, first stage in aerobic respiration

Question 9

Define phosphorylation

Answer 9

The addition of phosphate group to a molecule

Question 10

What is NAD? Full form?

Answer 10

-hydrogen carrier
-Nicotinamide adenine dinucleotide

Question 11

What is oxidation

Answer 11

Addition of oxygen, removal of hydrogen or electron from a substance

Question 12

What is reduction

Answer 12

Removal of oxygen, addition of hydrogen or electron to a substance

Question 13

What is the four stages of aerobic respiration and where does it take place?

Answer 13

1) glycolysis takes place in the cytoplasm of the cell
2) the link reaction takes place in the matrix of mitochondria
3) the Krebs cycle takes place in the matrix of the mitochondria
4) oxidative phosphorylation takes place in the inner mitochondrial membrane

Question 14

Describe glycolysis

Answer 14

(check textbook)

Question 15

Describe link reaction

Answer 15

(check textbook)

Question 16

Describe Krebs cycle

Answer 16

(check textbook)

Question 17

Describe oxidative phosphorylation

Answer 17

(check textbook)

Question 18

What is decarboxylation

Answer 18

Removal of CO2 from a substance

Question 19

What is dehydrogenation

Answer 19

Removal of hydrogen from substance

Question 20

Define CoA

Answer 20

Molecule that supplies acetyl groups required for the link reaction

Question 21

Define acetyl CoA

Answer 21

Molecule made up of CoA and 2C acetyl group, important for the link reaction

Question 22

Define link reaction

Answer 22

Decarboxylation and dehydrogenation of pyruvate takes place, resulting in the formation of acetyl CoA, linking glycolysis and Krebs cycle

Question 23

Define Krebs cycle

Answer 23

A cycle of reactions in aerobic respiration in the matrix of mitochondria in which hydrogen passed to hydrogen carriers for subsequent ATP synthesis and some ATP is synthesized directly also known as the Citric acid cycle

Question 24

Define oxidative phosphorylation

Answer 24

The synthesis of ATP from ADP and Pi using energy from oxidation reaction in aerobic respiration

Question 25

What is electron transport chain(ETC)

Answer 25

A chain of adjacently arranged carrier molecules in the inner mitochondrial membrane, along which electrons pass in redox reaction

Question 26

What is redox reaction

Answer 26

A chemical reaction in which one substance is reduced and another is oxidised

Question 27

What is ATP synthase

Answer 27

The enzyme that catalyzes the phosphorylation of ADP to produce ATP

Question 28

What happens if there is no or very little oxygen inside mitochondria

Answer 28

-ETC stops working and no further ATP is formed by oxidative phosphorylation -no free carrier protein in the chain to accept hydrogen from reduced NAD and FAD, so these remain reduced -krebs cycle stops running because there is no oxidised NAD and FAD to enable the dehydrogenation steps to take place

Question 29

Describe how the structure of mitochondria is related to it's function

Answer 29

-It is a rod shaped or filamentous (0.5-1.0micrometre). -The no. of mitochondria in a cell depends on its activity. -Site of aerobic respiration -It has a double membrane, outer and inner membrane. Outer membrane is permeable to all small molecules, this allows the movement of substance required and produced by the link reaction, Krebs cycle and oxidative phosphorylation such as oxygen, carbon dioxide, ATP, ADP and Pi. The inner membrane is impermeable to H+. -the inner membrane is folded to form cristae which increases the surface area. -On cristae are ATP synthase present where chemiosmosis takes place. -Between two membrane is the inter membrane space with high H+ concentration and a proton gradient is maintained. -Matrix fills mitochondria and is a site for link reaction and Krebs cycle. -Mitochondria has it's own looped DNA and 70s ribosomes for the synthesis of enzymes needed for link reaction and Krebs cycle.

Question 30

Define anaerobic respiration

Answer 30

Without oxygen

Question 31

What is ethanol fermentation

Answer 31

Anaerobic respiration in which pyruvate is converted to ethanol

Question 32

What is lactate fermentation

Answer 32

Anaerobic respiration in which pyruvate is converted to lactate

Question 33

What is the two type of fermentation taking place in anaerobic respiration and where?

Answer 33

-ethanolic fermentation takes place in yeast -lactate fermentation takes place in muscle

Question 34

What is the similarities of both lactate and ethanol fermentation

Answer 34

-in both fermentation, hydrogen is combined with pyruvate to give the end product -both are formed by glycolysis -both process results in oxidised NAD to be used again in glycosis. -only one product formed at the end to both fermentation -catalyst is needed for formation of end product

Question 35

What is the difference in both lactate and ethanol fermentation

Answer 35

Lactate fermentation -reversible reaction -one step process -catalyst is lactate dehydrogenase -end product is lactate -decarboxylation doesn't take place Ethanol fermentation -not a reversible reaction -two step process -catalyst is alcohol dehydrogenase -end product is ethanol -decarboxylation takes place

Question 36

What is aerenchyma

Answer 36

-Plant tissue containing air space (in roots&stems) -parenchyma + air= aerenchyma

Question 37

What is the adaptation of a rice plant?

Answer 37

-rice paddy grows upward faster, to keep its leaves and flower spikes above the water level, so that oxygen and carbon can be exchanged through stomata of the leaves -stems and roots contain aerenchyma so that gases can diffuse to parts like roots which are underground enabling to respire aerobically -cell in roots undergo anaerobic respiration that lead to ethanol build up in tissues. These cell are tolerant to high ethanol concentration, which is broken down by ethanol dehydrogenase. This allows the plant to grow actively even when oxygen is scarce, using ATP produced by ethanol fermentation.

Question 38

RQ formula

Answer 38

-RQ= volume of carbon dioxide given out in unit time/ volume of oxygen taken in unit time -RQ= moles or molecules of Carbon dioxide given out/ moles or molecules of oxygen taken in

Question 38

What is the energy density of carbohydrate, lipid and protein

Answer 38

Carbohydrate: 15.8kJ/g Lipid: 39.4kJ/g Protein: 17.0kJ/g

Question 38

What is the respiratory quotient (RQ) of carbohydrate, lipid and protein

Answer 38

Carbohydrate: 1.0 Lipid: 0.7 Protein: 0.9

Question 39

What is redox indicators

Answer 39

A substance that changed colour when it is oxidised or reduced

Question 40

What are the two redox indicators and what is the colour change

Answer 40

-DCPIP -Methylene blue Blue to colourless when reduced

Question 41

Describe the structure and role of ATP

Answer 41

-It is a nucleotide -adenine+ribose+3 phosphate -small packets of energy -water soluble so can move around the cell -protein synthesis -used by the cell as immediate energy donor

Question 42

What is the role of ATP in active transport and anabolic reaction?

Answer 42

ATP provides energy Active transport -binds to ion -movement against concentration gradient -protein changes shape -carrier transport protein Anabolic reaction -synthesis of complex substance from simpler ones -glycosidic bond -ester bond -polypeptide/protein from amino acid