Cellular Energetics

Question 1

Where do cells get energy from?

Answer 1

Food molecules

Question 2

What is the difference between autotrophs and heterotrophs?

Answer 2

Autotrophs metabolise by photosynthesis
Heterotrophs metabolise by cellular respiration

Question 3

What is the process of breaking down food molecules called?

Answer 3

Catabolism

Question 4

What is the word equation for metabolism?

Answer 4

Anabolism+catabolism= Metabolism

Question 5

What are the 3 main stages of cellular respiration(aerobic)?

Answer 5

Glycolysis
The link reaction
Krebs cycle

Question 6

What is the structure of ATP?

Answer 6

3 phosphate
Nitrogenous base
Ribose

Question 7

What is ATP used for and how is it used for this?

Answer 7

Energy currency
Hydrolysis of high energy phosphate bonds

Question 8

What is ATP converted to after releasing energy?

Answer 8

ADP

Question 9

How many ATP’s are each NADH worth?

Answer 9

2.5

Question 10

How many ATP’s are each FADH worth?

Answer 10

1.5

Question 11

What happens in glycolysis?

Answer 11

Glucose goes to two molecules of pyruvate.
Happens in the cytoplasm
No oxygen needed

Question 12

What happens in the link reaction?

Answer 12

Pyruvate transfers to acetyl CoA
In the matrix of the mitochondria
Requires oxygen

Question 13

What happens in the Krebs Cycle?

Answer 13

Oxidation of acetyl group in CO2 with CoA release
In the matrix of mitochondria
Requires oxygen

Question 14

What two processes happen in the oxidative phosphorylation?

Answer 14

Electron transport chain and chemiosmosis

Question 15

What happens during oxidative phosphorylation?

Answer 15

High energy electrons pass through the complex in the matrix of the mitochondria
Requires oxygen

Question 16

What are the 2 fates of pyruvate?

Answer 16

Fermentation and oxidation/ decarboxylation into acetyl-CoA

Question 17

What are the two systems of fermentation pyruvate could go through?

Answer 17

Lactic fermentation
Ethanol fermentation

Question 18

What happens in lactic fermentation?

Answer 18

Pyruvate is reduced to lactic acid
Occurs in the muscle cells in the cytoplasm
Absence of oxygen
No energy production

Question 19

What is the word equation for lactic fermentation?

Answer 19

Glucose+2ADP +2Pi= 2lactate +2ATP +2H2O

Question 20

What happens in ethanol fermentation?

Answer 20

Pyruvate is reduced to ethanol and CO2
Occurs in bacteria and yeast cells in the cytoplasm
No energy production
In the absence of oxygen

Question 21

What is the word equation for ethanol fermentation?

Answer 21

Glucose+ 2ADP +2Pi=2 ethanol +2CO2 +2H2O +2ATP

Question 22

What happens in the pyruvate oxidation/decarboxylation into Acetyl-CoA?

Answer 22

Links glycolysis to the Krebs cycle
Presence of oxygen
Pyruvate is pumped into the mitochondrial matrix

Question 23

What is the word equation for the pyruvate oxidation/decarboxylation into Acetyl-CoA?

Answer 23

2 pyruvate + 2CoA+ 2NAD—> 2acetyl-CoA +2CO2+ 2NADH

Question 24

How do we release fatty acids?

Answer 24

Lipases hydrolyse ester bonds to release fatty acids from triacylglycerol.