Bioenergetics - Chap 3 Flashcards
Define Metabolism
All chemical reactions in the body that result in:
Catabolism: breakdown of cell components/molecules
Anabolism: build up of cell components/molecules
Define Bioenergetics
Metabolic pathways specifically involved converting food into energy
In what form is Glucose stored in the body?
Glycogen
In what form is Fat stored in the body?
Triglycerides
What are the primary sites for Glucose storage in the body?
Liver and Muscle
What are the primary sites for Fat storage in the body?
Muscle and Adipose tissue
What is the 1st law of Thermodynamics?
Energy is not created or destroyed but transfers from one form to another
What is the 2nd law of Thermodynamics?
Transfer of potential energy always proceeds in direction that decreases the capacity to perform work (conversion to heat is ultimate fate of chemical energy)
What is Anaerobic?
- Does not require O2
- Phosphocreatine breakdown and Glycolysis
What is Aerobic?
- Requires O2
- Oxidative Phosphorylation
How efficient is the the process of bioenergetics?
Not efficient
What is the percent energy released from our nutrients is captured by ADP to synthesize ATP? versus released as heat?
25% captured by ADP to synthesize ATP versus 75% released as heat
Why do athletes ingest creatine to improve exercise performance?
- Immediate source of energy in muscle
- The larger our PCr reserves, the longer we can sustain intense muscular activity
Identify the cellular location for Anaerobic Metabolism (glycolysis)
Cytoplasm (Glycolysis)
Identify the cellular location for Aerobic Metabolism (3 stages)
Mitochondria (Glycolysis, Krebs Cycle, ETC)
What nutrient can only be broken down by Glycolysis?
Glucose (carbohydrates)
The end product of glycolysis has two options. What are they?
- In absense of sufficient oxygen pyruvate is converted to Lactate
- If oxygen is available. Enter Mitochondria and be converted into Acetyl CoA for further Oxidation.
What are the 3 stages of aerobic metabolism?
- Generation of Acetyl CoA
- Krebs Cycle
- ETC
What are the events necessary (in order) required for full oxidation of a molecule of glucose?
- Generation of Acetyl CoA
- Krebs Cycle
- ETC
What are NAD and FAD and why are they important?
NAD and FAD are energy carriers. They are the oxidizing agents and accept electrons.
Why is oxygen so important for aerobic metabolism - and life in general?
- Allows for ETC to function
- If the last cytochrome retained the electrons. it wouldn’t be able to accept more, and the ETC would STOP
- It can accept the electrons from NADH and allow for continuous electron flow
Who can oxidize Fat and Protein?
Oxidized by aerobic metabolism
Individual fatty acids from the triglyceride molecule will do what?
Cleaved into 2 carbon molecules (Acetyl CoA) by the process of Beta Oxidation
What is the rate limiting enzyme for PCr? and the primary modulator?
- Creatine Kinase(CK)
- ADP increases and is inhibited by high levels of ATP
What is the rate limiting enzyme for Glycolysis? and the primary modulator?
- Phosphofructokinase (PFK)
- ADP + Pi rise and enhance PFK activity
What is the rate limiting enzyme for the Krebs Cycle? and the primary modulator?
- Isocitrate Dehyrogenase
- Inhibited by ATP and Stimulated by increasing levels of ADP + Pi
