Energy Metabolism

Question 1

Where do cells get energy?

Answer 1

Nutrients or fuels such as carbohydrates, Proteins and lipids

Question 2

What are the 2 metabolic processes?

Answer 2

Anabolic processes - create larger molecules. Require energy.
Example: bonding of amino acids to make proteins

Catabolic processes - larger molecules are broken down to smaller ones. Release energy . Example: glucose breakdown

Question 3

Why do cells conserve some energy?

Answer 3

To generate a metabolic currency Adenosine Triphosphate, ATP

Question 4

What is ATP, what is is made of?

Answer 4

ATP is a high-energy molecule composed of adenine (purine base), ribose, and three phosphate groups

Question 5

What products created in hydrolysis of ATP?

Answer 5

ADP, Pi
Also energy

Question 6

What bonds do ATP have and what do they produce?

Answer 6

Two phosphoanhydride bonds, when the first is hydrolysed it produces ADP and when the second is hydrolysed it produces AMP

Question 7

How does ATP provide energy? 76358927358273

Answer 7

When the phosphate bonds are
broken energy is released BUT to
‘break’ bonds an input of energy
is required. As bonds reform in the
products of the reaction of the
hydrolysis of ATP energy is
released. The energy released
making the new bonds is greater
than the energy required to
hydrolyse the bonds (since they
are relatively weak) thus meaning
the hydrolysis of ATP gives out
energy

Question 8

Which glucose metabolism pathways is ATP made in?

Answer 8

1. Glycolysis - anaerobic break down of glucose to pyruvate. Small amount of ATP generated by substrate level phosphorylation
2. Krebs’ Cycle - oxidation of Acetyl CoA to CO. generates coenzymes: NADH and FADH2

3, Oxidative phosphorylation - transduction of energy derived from fuel oxidation to high energy phosphate. Generates large amounts of ATP.

etc. Beta oxidation, ETC, s.l phosphorylation

Question 9

Where does glycolysis occur?

Answer 9

Occurs in cytosol under anaerobic conditions of mitochondria.

Question 10

Why does glycolysis occur?

Answer 10

• Emergency energy producing pathway when oxygen is limiting
• Generates precursors for biosynthesis eg pyruvate, Glycerol-3-P

Question 11

What are the reactant and products of glycolysis? 38583457

Answer 11

R - Glucose
P - 2 molecules of pyruvate C3H4O3, 2 NADH + H+ , 2 ATP

Question 12

What are the 2 phases of glycolysis and what happens in brief?

Answer 12

• Preparative phase
  Glucose (2 ATP) into Fructose-1,6-bisphosphate
• ATP Generating phase
  2 Triose phosphates (2 NADH, 4 ATP) into 2 Pyruvate

Question 13

Explain preparative phase of glycolysis:

Answer 13

Glucose > (ATP + Hexokinase) > Glucose-6-phopsphate > (Phosphoglucoisomerase) > Fructose-6-phosphate > (ATP+ Phosphofructosekinase) > Fructose-1,6-bisphosphate > (Aldolase) > Dihydroxyacetone phosphate > (Triosephosphate isomerase) > Glyceraldehyde-3-phosphate

Question 14

Explain ATP generating phase:

Answer 14

2x Glyceraldehyde-3-phosphate > (2NAD+, 2Pi) > 2x 1,3-Bisphosphoglycerate > (2ADP + Phosphoglycerokinase) > 2x 3-Phosphoglycerate > (Phosphoglcyeromutase) > 2x 2-Phosphoglycerate > (Enolase) > 2x Phosphoenolpyruvate > (2ADP + Pyruvate kinase) > 2x Pyruvate