Respiratory substrates

Question 1

Word equation

Answer 1

glucose + oxygen- carbon dioxide + water vapour+ energy

Question 2

Chemical equation

Answer 2

C6H12O6 +6O2-6CO2+6H20

Question 3

When different substrates broken down in respiration…

Answer 3

…release different amounts of energy

Question 4

Lipids

Answer 4

Fat-(lipase)-glycerol+ 3 fatty acids
-glycerol to pyruvate
-3 fatty acids to 50 acetyl coA and 500 ATP

Question 5

Proteins

Answer 5

Protein-(protease)-amino acids
-amino acids go through deamination (requires ATP) to pyruvate

Question 6

Carbohydrates

Answer 6

Carbohydrate-(amylase)-simple sugars for pyruvate

Question 7

Lipids have the highest energy value because…

Answer 7

…lipids broken into fatty acids have a higher hydrogen content (made of long hydrocarbon chains) which are released will result in a greater proton gradient across the mitochondrial membrane which allows for formation of more ATP via chemiosmosis

Question 8

How hydrogen atoms affect the amount of energy released?

Answer 8

More hydrogen atoms in a molecule- more hydrogen transported by NAD and FAD to mitochondrial membrane- greater chemiosmosis/proton gradient-more ATP produced via chemiosmosis

Question 9

Respiratory Quotient definition

Answer 9

the ratio of carbon dioxide molecules produced to oxygen molecules taken in during respiration

Question 10

RQ values of different respiratory substrates

Answer 10

-this is because of the number of carbon-hydrogen bonds differs in each type of biological molecule
-+ =+ H atoms used to create a proton gradient
-+H = +ATP produced
-+ O2 requires to breakdown molecule (to be final electron acceptor- in last step of oxidative phosphorylation to form water)

Question 11

Glucose RQ value

Answer 11

1

Question 12

Carbohydrate RQ value

Answer 12

1

Question 13

Lipids RQ value

Answer 13

0.7

Question 14

Protein RQ value

Answer 14

0.9

Question 15

RQ value formula

Answer 15

RQ= moles or molecules of CO2 given out/moles or molecules of O2 taken in

Question 16

Use of RQ values

Answer 16

1)For an organism is useful because it tells you what kind of respiratory substrate and what type of respiration
2)High RQs=organism is short of O2
3)Plants sometimes have a low RQ due to CO2 released used for photosynthesis

Question 17

Measuring the rate of respiration using a respirometer process

Answer 17

1.Set up apparatus-manometer contains liquid that moves as oxygen in tube A is used up
2.The germinating seeds release carbon dioxide
3.Carbon dioxide is absorbed by the sodium hydroxide-therefore has no effect on volume of air inside tube A
4.Germinating seeds use up oxygen-this decreases volume of air in the tube
5.Rate of movement of liquid in manometer indicator of rate of respiration
6.Can change environmental conditions such as temperature, light intensity to observe how these factors affect rate of respiration

Question 18

What are respirometers used for?

Answer 18

Used to measure and investigate the rate of aerobic respiration by measuring the amount of oxygen consumed by an organism over a period of time (RQs)

Question 19

Volume of oxygen consumed formula

Answer 19

pixr^2xh or pixr^2xl/time taken
-where l=distance travelled by fluid

Question 20

What is syringe for?

Answer 20

Resets the liquid in the manometer allowing you to take measurements over a specified period of time

Question 21

RQ analysis

Answer 21

-can be used in experiments to investigate how different factors affect the RQ of organisms over time
-when RQ value changes it means the substrate being respired has changed
-some cells may also be using a mixture of substrates in respiration
-RQ value of more than 1 suggests excessive carbohydrate/calorie intake
-RQ value of less than 0.7 suggests underfeeding