Chapter 7 - Cell Respiration

Question 1

What is the purpose of cellular respiration?

Answer 1

To create ATP to be used as usable energy

Question 2

Why can we not use glucose as cell energy?

Answer 2

Because glucose is too much energy to be used at once, we need to break it apart into many ATP to be used as immediate energy for many processes within the cell

Question 3

What are the reactants and products of cellular respiration?

Answer 3

C6H1206 (s) + O2 (g)&raquo_space; CO2 (g) + H2O (l) + Energy

Question 4

What are the electron carrier molecules? What do they do?

Answer 4

FAD+/FADH NAD+/NADH are electron carriers. These molecules transfer electrons through oxidation/reduction reactions.

Question 5

What does oxidation do? How does this help in cellular respiration?

Answer 5

The oxidation of NADH and FADH2 releases energy to be used by ADP and Pi that can help create ATP

Question 6

What are the abilities of ATP?

Answer 6

• Motion
• Transport
• Building molecules
• Switching enzymes on and off
• Bioluminescence

Question 7

How efficient is cell respiration?

Answer 7

36% efficient. The other 64% of the lost energy helps animals regulate their body temperature

Question 8

How much ATP does aerobic cell respiration produce? How much ATP does anaerobic cell respiration produce?

Answer 8

Aerobic: 36
Anaerobic: 2

Question 9

Where does Glycolysis take place?

Answer 9

Glycolysis takes place within the cytoplasm of cell

Question 10

What happens in Glycolysis?

Answer 10

Glucose (6-C) enters glycolysis and splits into two Pyruvates. Energy is provided for this by ATP > ADP +Pi oxidation reactions which also create 2 NADH’s (which go to the ETC’s immediately). H+ ions are also used here, but they are taken right back into the cytoplasm. Enough energy is now released for 4 ADP + Pi to bond together and form 4 ATP

Question 11

What are the products of Glycolysis?

Answer 11

2 ATP 2 FADH 2 Pyruvate

Question 12

Where does Pyruvate oxidation take place?

Answer 12

Mitochondrial Matrix

Question 13

What happens in Pyruvate oxidation?

Answer 13

a 3-C pyruvate enters, and with the help of Co-enzyme A turns into Acetyl CoA (2-C). AS carbon is lost in this step because CO2 comes out as a waste product. Also in this step, NAD+ reduces to NADH with the help of H+ ions which provide energy

Question 14

What are the products of pyruvate oxidation? (For every two pyruvate that enter)

Answer 14

2 NADH+ 2CO2 2Acetyl CoA

Question 15

Where does the Krebs cycle take place?

Answer 15

Mitochondrial matrix

Question 16

What is the Krebs cycle?

Answer 16

Acetyl CoA enters, and is immediately stripped of its CoA, Two carbons leave in the form of CO2. 3 NADH are formed, 1 ATP is formed, and 1FADH2 is formed.

Question 17

What are the products of the Krebs cycle? (2 turns)

Answer 17

6 NADH 2 ATP 2 FADH2

Question 18

Where do ETC and Chemiosmosis take place?’

Answer 18

Inner Mitochondrial Membrane

Question 19

What happens in the ETC and Chemiosmosis stage of cellular respiration? What do NADH and FADH2 have to do with this stage

Answer 19

NADH gives up 2 electrons to be used in the ETCs. As these two electrons go through the ETC, they produce energy to bring H+ ions over the inner membrane and out of the mitochondrial matrix through proton pumps. NADH and FADH2 continuously give the ETCs electrons, but FADH2 has less energy than NADH, meaning NADH’s electrons can pull more H+ ions than FADH2 can. NADH is responsible for 3 ATP, while FADH2 can make 2 ATP. When the 2 electrons reach a low energy state, they form two H+ ions and an Oxygen atom which forms water.
ATP are formed when the H+ ions create an electrostatic positive charge within he inner membrane space so much so that it pulls them through the ATP synthase, generating enough energy to form ATP from ADP and Pi.

Question 20

How many NADH and FADH go into the fourth stage of cellular respiration? How many ATP come out?

Answer 20

2 ATP 2FADH2 - Glycolysis (6 ATP)
2NADH - Pyruvate oxidation (6 ATP)
2ATP 6NADH 2FADH2 - Krebs (24 ATP)
= 36 ATP

Question 21

Why does anaerobic cell respiration need to Ferment?

Answer 21

Because NAD+ is a finite resource within an anaerobic cell and if NAD+ runs out, glycolysis will halt. There has been evolution for anaerobic cell respiration to get around this flaw.

Question 22

What does NADH give its H+ ions to in alcohol fermentation?

Answer 22

Acetaldehyde, this then forms ethanol

Question 23

What does NADH give its H+ ions to in Lactic Acid fermentation?

Answer 23

Pyruvate, this forms lactic acid

Question 24

How is lactic acid transported? And to where?

Answer 24

Its transported through the bloodstream, from the muscles, and to the liver.

Question 25

What happens when you no longer need to be in anaerobic respiration? (Specifically after a strenuous exercise)

Answer 25

Lactic acid is converted back into pyruvate which then goes through aerobic respiration as normal

Question 26

What is oxygen debt?

Answer 26

The extra oxygen required to chemically process lactic acid that is now going back into the form of pyruvate