Energy Reactions in Cells Flashcards
Define metabolism
Inter conversion of biological molecules in small chemical steps to support repair, growth and activity of tissues to sustain life
Where can cell metabolism occur?
- All cells
- Some cells
- Cell compartments
What are the 4 stages of a metabolic pathway?
- Start Point
- Intermediate (Metabolite)
- End Point
- Interconnections
Define a Catabolic Reaction and name 3 characteristics
Large molecules are broken down into smaller molecules
- Release free energy
- Oxidative
- Release H atoms
Define an Anabolic Reaction and name 2 characteristics
Synthesis of larger cellular components from Metabolites
- Uses energy from catabolism
- Reductive
What do all biological metabolic pathways release?
CO2 and H2O
What are the 4 products of Catabolic Metabolism and give an example of each
Building Block Materials - Sugars, Amino Acids, Fatty Acids
Organic Precursors - Acetylcholine CoA
Biosynthetic Reducing Power - NADH, NADPH
Energy for Cell Function - ATP
What is Biosynthetic Work?
Energy required for the anabolic synthesis of cellular components
What is Transport Work?
Maintenance of ion gradients and nutrient uptake at membranes
Name 3 types of specialised function work that require energy and give an example of each
Mechanical Work - Muscle contraction
Electrical Work - Nervous impulse conduction
Osmotic Work - Kidney
What 3 elements add up to give a person’s energy requirement?
- Basal Metabolic Rate
- Activity
- Specific Dynamic of Food
What are the two types of Chemical Bond Energy?
Exergonic - Release of energy and spontaneous
Endergonic - Require energy
Describe Exergonic and Endergonic energy in terms of free energy
Exergonic has free energy < 0
Endergonic has free energy > 0
What is a Redox Reaction?
Oxidation accompanied by Reduction
What does oxidation release in redox reactions?
Chemical bond energy
What are Hydrogen Carrier Molecules?
They carry electrons and protons from oxidation
What is constant in Hydrogen Carrier Molecules?
Total concentration of oxidised and reduced carriers
Name 2 processes that use Hydrogen Carrier Molecules
- ATP Production
- Biosynthesis
What are the 3 major Hydrogen Carrier Molecules?
- NAD
- NADP
- FAD
How is reducing power converted to energy currency?
Oxidative Phosphorylation
What energy powers phosphorylation of ADP?
Energy released in Exergonic reactions
What happens when ATP levels are high?
Anabolic pathways are activated
What happens when there is low ATP and high ADP/AMP?
Catabolic pathways are activated
What enzyme converts ADP to ATP and AMP?
Adenylate Kinase
What is the purpose of Creatine Phosphate?
Allows immediate use of high energy stores
How is Creatine Phosphate produced?
Reaction catalysed by Creatine Kinase and phosphorylated by ATP
What is special about the formation reaction of Creatine Phosphate?
It is easily reversible allowing it to quickly respond to varying levels of ATP
What is the value of Creatine Kinase in diagnosis?
- Released from cardiac myocytes when damaged
- High level in the blood indicative of an MI
What is Creatinine and how is it produced?
- Breakdown product of Creatine
- Produced by a spontaneous reaction at a constant rate
Name 2 clinical applications of Creatinine measurement
- Measure of muscle mass
- Marker of urine dilution
