Energy Reactions In Cells

Question 1

Define cell metabolism…

Answer 1

Highly integrated network of chemical reactions within cell → contains metabolic pathways which link

Question 2

Describe anabolic pathways..

Answer 2

synthesise larger cellular components from smaller molecules;
reductive;
use energy generated from catabolic pathways (ATP + intermediate metabolites)

Question 3

Describe catabolic pathways…

Answer 3

→ breakdown of larger molecules into smaller ones
→ release large amounts of free energy
→ oxidative, high reducing power as release H+ atoms

Question 4

Functions of cell metabolism?

Answer 4

→Energy for synthesis of cell components
→ organic precursor molecules allowing interconversion of building block molecules
→ biosynthetic reducing power used in synthesis of cell components

Question 5

Definition of isothermal?

Answer 5

Cannot use heat energy to do work; humans are isothermal

Question 6

How are endergonic and exergonic reactions linked?

Answer 6

Redox reactions, when fuel molecules oxidised= H+ transferred to carrier molecules that become reduced

Question 7

Major carrier molecules?

Answer 7

NAD, NADP, FAD

Question 8

How are carrier molecule components gained?

Answer 8

Cannot be synthesised in body, have to be supplied in diet through vitamins

Question 9

Name the 4 high energy signals that activate anabolic pathways

Answer 9

ATP, NADH,NADPH, FAD2H

Question 10

Name the 5 low energy signals that activate catabolic pathways

Answer 10

ADP, AMP, NAD+, NADP+, FAD

Question 11

Effect of AMP on ATP generation?

Answer 11

↑ ATP generation via glycolysis

Question 12

Role of adenylate kinase?

Answer 12

Catalyses reversible conversion b/w ADP to ATP and AMP
2ADP → ATP + AMP

Question 13

What reserve is used as high energy stores when metabolic activity needs to be ↑ quickly?

Answer 13

Creatine phosphate as can be used immediately

Question 14

Reaction to produce creative phosphate?

Answer 14

Creatine + ATP ←→ Creatine phosphate + ADP

→ when ATP ↑, Creatine phosphate formed
→ when ATP ↓ , reaction reversed to boost ATP conc.

Question 15

What is Creatine kinase a marker of?

Answer 15

Marker of muscle damage (myocyte damage) → used for patients wl suspected muscle injury or myopathy

Question 16

Structure of CK and where is it found?

Answer 16

Made up of 2 subunits (M, B)
Cytosolic enzyme therefore appears in blood soon after cell damage

Question 17

Where is creatinine excreted from?

Answer 17

Kidneys

Question 18

What is creatinine used for?

Answer 18

• Assess kidney function
• provide measure of muscle mass ( ↑ levels if muscle wasting damage)
• estimate urine dilution