BioEnergentics Final Flashcards
Substrates
Fuel sources from which we make energy; they are: carbs, fats, and proteins
What is bioenergetics?
the process of converting substrates (carbs, fats, proteins) into energy
What is metabolism?
highly integrated network of chemical reactions essential to viability of living organisms
What unit is energy release measured in?
calories (cal): amount of heat energy needed to raise 1g of water 1 degree celcius
What unit is energy release typically measured in in humans?
kilocalorie (kcal) which is equal to 1000 calories
What is an endergonic reaction?
a reaction that requires energy to be added to the reactants before the reaction can start
What is an exergonic reaction?
a reaction that needs to give off energy as a result of chemical processes
What storage form is food converted into in order to create energy?
ATP
What are the three primary sources of energy/fuel?
carbs, fats, proteins
Energy is released when chemical bonds are:
broken
How many kcals do carbs provide, and how many kcals are stored in the body?
provides 4kcal/g and stores 2500 kcal
Extra glucose is stored as ___ in the liver and muscles
glycogen
Stores of CHO are limited and can be depleted during:
prolonged exercise
When is glycogen converted back to glucose?
when more ATP is needed
How many kcals do fats provide?
9 kcal/g
What is an efficient substrate and has efficient storage?
fat
What is the form that fats are stored in?
triglyceride
Triglycerides are broken down by a process called:
lipolysis
Only ___ are used to form ATP
FFA’s (free fatty acids)
How many kcals do proteins provide?
4 kcal/g
In order for proteins to be used, they must first be converted into:
glucose via gluconeogenesis
The process of converting protein and carbs into FFAs is called:
lipogenesis
What percent of energy can proteins provide during prolonged exercise?
5-10%
The speed of cellular chemical reactions is regulated by:
catalysts
What do enzymes do?
they facilitate reactions by lowering the activation energy
What is an example of an enzyme that is used to break down ATP?
ATPase
Transport work is also known as:
active transport
Examples of chemical work:
glycerol + FA > tiaclygycerol
amino acids > proteins
Examples of mechanical work:
- contractile cells
- muscle contraction
- protein filaments convert chemical energy to mechanical energy
What is the process of breaking down ATP to release energy with water called?
hydrolysis
How much ATP is stored?
very little amount
Stored ATP is the primary supplier of energy for the first ___ seconds of intense exercise.
1-3
What are the two immediate energy systems?
stored ATP and phosphocreatine
Phosphocreatine is a reaction catalyzed by:
creatine kinase
Creatine Kinase is an example of a ___ ____ enzyme.
rate limiting
Creatine phosphate is an ___ reaction, meaning it does not require oxygen.
anaerobic
Creatine Phosphate is used during ___ ___ activity.
high-intensity
There is enough creatine phosphate stored in muscle for about ___ seconds of exercise.
10-20
As ATP is used, creatine phosphate reforms more ATP from:
ADP
Creatine Phosphate recycles ATP during exercise until it is used up which is around ____ of maximal exercise.
3-15 seconds
Creatine Kinase controls the rate of ___ production
ATP
When ATP levels increase, creatine kinase activity ____
decreases
Levels of ATP are maintained early during sprinting exercise by:
phosphocreatine breakdown
When PCr is depleted, __ declines (in prolonged exercise)
ATP
At exhaustion, ___ ___ activity is inhibited
creatine kinase
What is the duration of anaerobic glycolysis?
15 seconds to 2 mins
What many ATP does glycolysis yield?
2 ATP for every 1 molecule of substrate
What supplies most of the energy for ATP resynthesis at first?
intramuscular glycogen
What is used after intramuscular glycogen?
blood glucose which comes from liver glycogen
In glycolysis, glucose and glycogen both need to convert to:
glucose-6-phosphate
In glycolysis, how much ATP does it cost when starting out with glucose? glycogen?
glucose: 1
glycogen: 0
Where do all steps of glycolysis occur?
cytoplasm
In glycolysis, glucose is transported into the cell via:
mediated transport
What is the enzyme that helps to convert glucose to glucose-6-phosphate?
hexokinase
What is the enzyme that helps convert glucose-6-phosphate to fructose 1,6-biphosphate?
phosphofructokinase (PFK)
What are the two rate limiting steps of glycolysis?
- adding phosphate to glucose required ATP and hexokinase
- adding phosphate to already phosphorylated fructose requires ATP and PFK
The anaerobic breakdown of glucose has a net ATP of:
2
What is the end product of glycolysis?
pyruvate
When there is adequate oxygen, what is the fate of pyruvate?
goes to the citric acid cycle via acetyl CoA molecule, results in more ATP produced
When there is NOT adequate oxygen, what is the fate of pyruvate?
pyruvate becomes lactate , no more ATP produced, inhibits PFK
If pyruvate levels are lowered, what can happen to lactate?
may be converted back to pyruvate
Following exercise with a “cool down” can do this to lactate levels
lowers lactate levels
Hydrogen in glycolysis that are removed from the reaction are accepted by:
NAD to form NADH
With adequate oxygen, NADH shuttles H+ into:
the mitochondria
Without adequate oxygen, NADH shuttles H+ to:
pyruvic acid to form lactic acid
What are two carriers of electrons that have high energy potentials?
NAD/H AND FAD/H
How many ATP does NADH help produce?
3
How many ATP does FADH help produce?
2
NADH is associated with the vitamin:
B3
FADH is associated with the vitamin:
B2
The citric acid cycle allows for the complete oxidation of:
Acetyl CoA
How many cycles of the citric acid cycle does 1 molecule of glucose go through?
2 cycles
What are the products of the citric acid cycle?
Water, CO2, NADH, H+, FADH, and GTP
Where does the citric acid cycle occur?
mitochondria
Does the citric acid cycle require oxygen?
yes
During glycolysis, pyruvate undergoes pyruvate decarboxylation to become:
acetyl-coA
How many ATP are produced during 2 complete cycles of the citric acid cycle?
20 ATP
How many of the 20 ATP formed from the citric acid cycle are from NADH, FADH, and GTP?
NADH: 15
FADH: 3
GTP: 2
What is Aerobic Metabolism?
energy derived from aerobic metabolism of glucose
How many ATP are produced from the aerobic conditions of glycolysis?
12
What is the total tally of ATP produced from 1 glucose molecule?
32 ATP/ 33 with glycogen
Oxidative Phosphorylation occurs in:
the mitochondria
Oxidative phosphorylation is a series of reactions involving:
cytochromes and cytochrome oxidase
Aerobic exercise training effects:
- increases number of mitochondria
- increases capillary density
- increases use of fatty acids
- reduces H+ production
Exercising longer and at a higher intensity allows for:
- glucose sparing
- maintaining pH
- maintaining lactate
Fats are the primary fuel source for muscle during ___ _____ exercise.
low-intensity
CHO are dominant substrate during ___ ____ exercise
high-intensity
During prolonged, low-intensity exercise, what is used as fuel?
shift from carbs to fats
