Energy & Respiration

Question 1

What is energy needed for in the body?

Answer 1

1.anabolic reactions- the synthesis of complex substances from simpler ones i.e DNA replication and protein synthesis
2.movement
3.active transports
4.temperature regulation

Question 2

What is the primary purpose of cellular respiration?

Answer 2

To convert biochemical energy from nutrients into adenosine triphosphate (ATP).

Question 3

Fill in the blank: The three main stages of aerobic respiration are glycolysis, the Krebs cycle, and __________.

Answer 3

oxidative phosphorylation.

Question 4

What is glycolysis?

Answer 4

The process of breaking down glucose into pyruvate, producing a small amount of ATP.

Question 5

Multiple Choice: Which of the following is a product of the Krebs cycle? A) Glucose B) Oxygen C) Carbon dioxide D) Lactic acid

Answer 5

C) Carbon dioxide.

Question 6

What is the role of NADH in cellular respiration?

Answer 6

To carry electrons to the electron transport chain.

Question 7

True or False: Fermentation is a form of anaerobic respiration.

Answer 7

True.

Question 8

What is the main energy currency of the cell?

Answer 8

Adenosine triphosphate (ATP).

Question 9

Fill in the blank: In aerobic respiration, the final electron acceptor is __________.

Answer 9

oxygen.

Question 10

What is the function of the electron transport chain?

Answer 10

To create a proton gradient that drives ATP synthesis.

Question 11

What are the two main types of fermentation?

Answer 11

Lactic acid fermentation and alcoholic fermentation.

Question 12

True or False: ATP is produced in both anaerobic and aerobic respiration.

Answer 12

True.

Question 13

What is the overall equation for cellular respiration?

Answer 13

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP.

Question 14

Fill in the blank: The process by which glucose is converted into pyruvate is called __________.

Answer 14

glycolysis.

Question 15

What is substrate-level phosphorylation?

Answer 15

The direct synthesis of ATP from ADP during a biochemical reaction.

Question 16

Multiple Choice: Which molecule is produced during the Krebs cycle? A) Glucose B) ATP C) Pyruvate D) Acetyl-CoA

Answer 16

B) ATP.

Question 17

What is the difference between aerobic and anaerobic respiration?

Answer 17

Aerobic respiration requires oxygen, while anaerobic respiration does not.

Question 18

Fill in the blank: The process of ATP production using the proton gradient is called __________.

Answer 18

chemiosmosis.

Question 19

What is the net gain of ATP from glycolysis?

Answer 19

2 ATP.

Question 20

Multiple Choice: Which of the following occurs in the mitochondria? A) Glycolysis B) Krebs cycle C) Fermentation D) All of the above

Answer 20

B) Krebs cycle.

Question 21

What is the primary role of oxygen in aerobic respiration?

Answer 21

To act as the final electron acceptor in the electron transport chain.

Question 22

True or False: FADH2 is produced during glycolysis.

Answer 22

False.

Question 23

Fill in the blank: The enzyme that synthesizes ATP during oxidative phosphorylation is called __________.

Answer 23

ATP synthase.

Question 24

Describe the structure of ATP

Answer 24

Its made up of:
-ribose sugar
-adenine (nitrogenous base)
-3 phosphate groups

Question 25

What makes ATP a suitable universal energy currency?

Answer 25

1.small 2.water-soluble 3.easily hydrolysed to release energy 4.easily transported around the cell 5.relatively large quantity of energy released (30.5 Kjmol) 6.rapid turnover rate (can be quickly made and broken/used up) 7.radily available in cells on demand

Question 26

Describe the process of ATP synthesis

Answer 26

1. chemiosmosis occurs 2. it occurs in the inner mitochondrial membrane (or in the thylakoid membrane) 3.ATP is synthesised using electrical potential energy ( this is energy from the transfer of electrons carried by electron carries like NADH & FADH via the electron transport chain) 4. the electrons cause conformation changes in the shapes of the proteins and cause them to pump H+ across a selectively permeable membrane 5. the uneven distribution of H+ ions across the membrane establishes both concentration and electrical gradient (electrochemical gradient) 6.H+ are allowed to flow down their concentration gradient via facilitated diffusion through ATP synthase 7.the transfer of 3H+ allows the production of 1 ATP molecule (3:1) 8.as H+ travel through the ATP synthase complex provided by the electrochemical gradient that produces ATP

Question 27

Structure of ATP synthase

Answer 27

- it has 6 binding sites; 3 of them are catalytically unreactive and only bind ADP -the other 3 subunits bind with catalyse the ATP synthase (hence why 3H+ produces 1 ATP)

Question 28

Which substrate between carbohydrates has the highest energy density value?

Answer 28

lipids have the highest one (39 .4) carbohydrates 15.8 lipids 39.4 proteins 17.0

Question 29

Why do carbohydrates have the lowest energy density?

Answer 29

-energy in aerobic respiration comes from the removal of hydrogen to water when reduced NAD and FAD are passed onto the ETC

Question 30

Why more ATP can be synthesised in aerobic respiration from one gram of lipid

Answer 30

1)lipids contain relatively more hydrogen atoms 2) more reduced NAD and FAD are produced 3) more electrons are passed along ETC 4) more hydrogens pumped across inner mitochondrial membrane

Question 31

Define the term respiratory quotient

Answer 31

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

Question 32

Equation for respiratory quotient

Answer 32

C02 produced/O2 consumed

Question 33

State the Rf values for the three different substrates

Answer 33

carbohydrates-1.0 lipids-0.7 proteins-0.9

Question 34

What do high values of RQ indicate?

Answer 34

alcohol fermentation is occurring

Question 35

Describe the experiment using respirometers to determine RQ

Answer 35

1. set up the respirometer *control tube must contain an equal amount of glass beads to the volume of organism being used 2.use the manometer reading to calculate change in gas volume within a given time

Question 36

Stages of glycolysis

Answer 36

1. Phosphorylation- glucose is phosphorylated by 2 ATP to form fructose bisphosphate 2. Lysis- fructose bisphosphate splits into two molecules of triose phosphate 3.Oxidation- hydrogen is removed from each molecule of triose phosphate and transferred to coenzyme NAD to form 2 reduced NADH 4. Dephosphorylation- phosphates are transferred from the intermediate substrate molecules to form 4 ATP through substrate linked phosphorylation 5.Pyruvate is removed- the end product of glycolysis is pyruvate which is used the in the next reaction ( the link reaction)

Question 37

Explain the link reaction

Answer 37

-it links gylcolysisa and the Krebs cycle -decarboxylation and dehydrogenation of pyruvate by a coenzyme (NAD) to produce an acetyl group -it combines of coenzyme A to form acetyl CoA pyruvate + NAD + CoA ----> acetyl CoA + CO2 + NADH

Question 38

What are the steps in the Krebs cycle?

Answer 38

1. Acetyl CoA brings the acetyl group to the Krebs cycle 2. the acetyl group is accepted by 4C oxaloacetate to form 6C citrate 3. 6C citrate then undergoes decarboxylation and dehydrogenation forming a 5C compound, C02 and NADH 4.this compound undergoes further decarboxylation and dehydrogenation (another 4 times) until eventually 4C oxaloacetate is reformed as well as CO2, NADH, FADH and ATP