Cellular Respiration & Metabolism

Question 1

Metabolism

Answer 1

It’s the sum of all the chemical processes occurring in an organism at one time
Concerned w/ management of material & energy resources in the cell.
Reactions break down big molecules into smaller units
OR
Build larger molecules from smaller components

Question 2

Anabolic (Biosynthetic) Pathways

Answer 2

Are pathways that consume energy to build larger, complicated molecules from simpler ones.
6CO2+ 6H2O + light → C6H12O6 +6O2
(Carbon dioxide, a low energy molecule, gets converted into carbohydrate, a high energy molecule.)

Question 3

Catabolic Pathways

Answer 3

Are pathways that release energy by breaking down complex molecules into simpler compounds.
- Cellular respiration
(Carbohydrate, a high-energy molecule, gets “digested” into carbon dioxide, a low energy molecule.)
Cells use released energy to make ATP

Question 4

Adenosine Triphosphate (ATP)

Answer 4

Energy molecules are used to shuttle energy between catabolic and anabolic reactions.
Energy is released from ATP through the loss of phosphate groups.

Question 5

Phosphorylation

Answer 5

It is when ATP gives a phosphate group to another molecule.

Phosphorylated molecules have “more” energy and can do the work of the cell.

Question 6

What is Cellular Respiration + examples

Answer 6

The making of ATP through the breakdown of foods.

• Aerobic Cellular respiration
• Fermentation

Question 7

What are the three stages of Cellular Respiration + Formula

Answer 7

Glycolysis - In the cytosol
Kreb’s Cycle - In the mitochondrial matric
Electron Transport Chain - At the inner membrane of mitochondria
C6H12O6 + 6O2 → 6CO2 + 6H2O + 38 ATP

Question 8

What happens in the Mitochondria and where?

Answer 8

Releases the majority of ATP for the cell.
Has outer and inner membrane.
Kreb’s Cycle takes place in the matrix of the mitochondria.
Electron Transport Chain takes place across the INNER MEMBRANE

Question 9

Glycolysis

Answer 9

First step of CR
Takes place in the cell cytoplasm
Each glucose molecule gets converted into 2 PYRUVATE MOLECULES
Energy requiring and energy-releasing step
Energy net yield is 2 ATP and 2 NADH
PROCESS IS ANAEROBIC (does not require oxygen)
Is helped by enzymes along the way

Question 10

Kreb’s Cycle (Citric Acid Cycle)

Answer 10

Each pyruvate (carbohydrate) molecule is completely oxidised into carbon dioxide.
The energy released from these reactions results in the formation of 1 ATP molecules and 3 NADH molecules (2 ATP and 6 NADH in total)

Question 11

Electron Transport Chain

Answer 11

During this process (ETC), H+ is moved against a gradient.
The energy needed to do this is supplied by electrons carried by NADH
34 ATP ARE PRODUCED

Question 12

Cellular Respiration Formula (word & chemical)

Answer 12

Word equation:
Glucose + Oxygen → Carbon Dioxide + water + 38 ATP

Chemical Equation
C6H12O6 +6O2 → 6CO2 + 6H2O + 38 ATP

Question 13

Why do we need oxygen?

Answer 13

It is required by an organism that has mitochondria because it is used to keep the ETC running.
Oxygen pulls off electrons from the chain and combines 2 H+ to form H2O

Question 14

What if we DON’T have oxygen

Answer 14

We would still be able to make ATP from sugar, just not as much as usual.
Modifications of glycolysis (fermentation) reactions are used to release energy.

Question 15

Fermentation Reactions

Answer 15

Produces ONLY 2 ATP per glucose molecule
Must regenerate NAD+ resulting in the formation of either
Ethanol & CO2
OR
Lactic Acid

Question 16

Where does the 38 ATP come from?

Answer 16

2 ATP is USED in Glycolysis to split the glucose molecule to 2 PYRUVATES

4 are PRODUCED in GLYCOLYSIS

2 are PRODUCED in KREB’S CYCLE

34 are PRODUCED in ELECTRON TRANSPORT CHAIN

38 ATP are produced in one cycle of cellular respiration.