Exam 2 Flashcards
Bioenergetics
Chemical process involved with the production of cellular ATP
Energy
The capacity to do work
Work
exercise (force x distance)
Calorie
The amount of energy required to raise the temp. of one kg of water to 1 degree celsius
bomb calorimeter
exercise device in water (heat) that helps directly identify how many calories burned
indirect calorimeter
measuring O2 consumption gives you the same result
First Law of Thermodynamics
energy cannot be created or destroyed
Second Law of Thermodynamics
In every energy transformation some energy is converted into a non-useable form
Ex. some ATP in a cross-bridge is not used while some is used (~30-40% usable)
Free Energy
The energy that can be used (for things like muscle contraction (30-40%))
Entropy
Energy that is converted into the non-usable form (60-70%)
In human bodies this is heat bc heat is not usable to perform work, it only keeps us warm
Ultimate source of energy
the sun!!
Photosynthesis
Carbohydrate storage energy
Plant Chemicals
glucose, lipids, proteins
Nuclear Energy
The type of energy in the sun
Light energy
energy that travels from the sun to the earth
Chemical energy
plants are able to capture the light energy and store it chemically (we get these chemicals through ingesting the food)
Electrical Energy
action potentials that travel through t-tubules and then through the sarcolemma
Mechanical Energy
Muscle Contraction (heat)
Purposes of Food
The food we eat serves as a source of energy, regulates energy use, and helps with the formation of body structures
Carbohydrates
Composed of c, h, and o
Readily available in diet
transported in body as glucose and converted to glycogen in the liver and muscles (glycogenesis) (converted back to glucose in liver: glycogenolysis)
Stores are limited
How many calories are there per gram of carb?
Carbs have about 4 calories per gram
Forms of carbohydrates
monosaccharides
disaccharides
polysaccharides
monosaccharides
one (glucose)
simple sugar
disaccharide
2
linking of 2 monosaccharides
simple sugar
polysaccharide
more than 10 sugar molecules together
3-9 sugar molecules
oligosaccharide
Monosaccharide EX.
The type of monosaccharide found in the human body is glucose
Glucose is down to many as blood sugar
Glucose is found in the foods we eat and is released from more complex carbohydrates
(absolutely necessary for proper functioning of the liver system)
Disaccharides
maltose
sucrose
lactose
Maltose
Plant source of glucose
Sucrose
Table sugar
Lactose
dairy sugar
Cellulose
indigestible by humans and consists of fibers
starch
storage form of carbs in plants (similar to glycogen)
Glycogen
liver/skeletal muscles; storage form of glucose for humans and animals
Glycogenolysis
Conversion of glycogen to glucose
Fats (Lipids)
Composed of carbon, hydrogen, and oxygen
Contain more energy per unit weight than carbohydrate or proteins (9 cals per gram w lipids)
Found in plant and animal foods (red meats, avocado, coconut)
Provide energy at rest and during prolonged, low-intensity exercise (aerobic exercise uses fats (lipids) through rest it inhibits fats)
Types of Fats
Simple Fats
Compound Fats
Derived Fats
Simple fats
Triglycerides
Compounds Fats
Phospholipids
Lipoproteins(protein covering the transport form)
Some lipoproteins are healthy and some are unhealthy
Derived Fats
Cholesterol
Steroids
Many steroids and hormones are derived from cholesterol
Structure of Triglycerides
Backbones: glycerol (form of alcohol)
plus 3 different fatty acids
R1, R2, R3 (fatty acids)
Fatty acids have a lot of energy for ATP production
Triglycerides are the main storage form of fat
Both the glycerol and fatty acids may be used for energy (most fat is stored in fat cells)
Droplets of fat located in skeletal muscle
Type 1 fibers store more fat
Structure of Fatty Acid
High ratio of Hydrogen to Oxygen
H carries more energy for fat
Body Stores of Fats
Subcutaneous fat: underneath the skin
Visceral: surround the organs
Body stores of fuels and energy
everyone has more fats than carbohydrates
37,000 calories need to run a marathon
you cannot use fat/protein unless you’re simultaneously using carbs
using fats better means less carbohydrates
Proteins
composed of AA’s
Contain nitrogen, in addition to carbon, hydrogen, and oxygen
Primarily used to form body structures but may also be used for energy
Can be synthesized into 20 AA’s
Leucine
Triggers protein synthesis within the skeletal muscles #1 AA used in exercise
Protein use for energy
Glucose-Alanine Cycle (glyco: glucose / neo: new / genesis: to create)
To create carbs from non-carbs sources
Alanine: non-carb source
Good during aerobic exercise
Its all about sparing and making new cabs
Leucine (2)
Leucine is the most common AA used
We take AA and transfer it’s AA group from pyruvate and alanine
liver removes nitrogen
Leucine to make alanine to make glucose
ATP Molecule
energy is the glue that holds this together
myosin ATPase is built into the myosin head
we are transforming energy (the bulk of it is 60-70% heat)
30-40% free energy is used)
Coupled Reactions
Energy released from 1 reaction is used for another reaction that uses energy
Metabolism
sum total of chemical reactions occurring in the body
Exergonic Reactions
Release Energy
Endergonic reactions
Requires Energy
Catabolism
To breakdown (fats, carbs, proteins) Exergonic
Anabolism
To create (fats, carbs, proteins)
Endergonic
(muscle contractions)
ATP (2)
Atp is available for energy rapidly but is stored in limited amounts
The amount of ATP stored in the body can sustain maximal exercise for only a few seconds
Because of ATP’s limited availability, other sources of energy must be available in the cell to replenish ATP
Enzyme
protein that serves as a catalyst (makes things happen)
in order for a chemical reaction to occur, it requires energy
enzymes work by lowering the amount of activation energy
not changed but the chemical reactions they are in
Only react with one reactant called a substrate
Activation Energy
Amount of energy must be added to make a reaction go
Naming of Enzymes
Names end with the suffix “are”
Kinases
Dehydrogenases
Isomerases (Rearranges whats already there)
Factors Affecting Enzyme Activity
Temperature (when you exercise, muscle temp increases)
Acidity (high intensity exercise using includes an increase in acidity of blood
Co-Factors (metal ions that bind to the enzyme, making the active site properly shaped)
Co-Enzymes (vitamin derivatives that bind to enzyme making the site properly shaped)
Energy Systems
Provide energy to resynthesizes ATP
ATP > ADP + P + energy
all 3 of these are active in every moment of your life
Phosphagen System: involves transfer of phosphate from one compound to the other
Lactic Acid System
Aerobic System
Phosphagen System
ATP-PC; ATP-PCr; ATP-CP; Immediate energy system
Simplest energy system
Anaerobic (close proximity to the myofibrils)
Occurs in cytoplasm
High power, low capacity
Quickly reforms ATP from ADP + Pi
Power
how quickly an energy system that makes ATP = mole ATP /min.
Capacity
How much ATP it makes = moles ATP
Recreating ATP with PCr
Most of us store about 3-5x as much phosphocreatine as we do ATP
Regulation of Phosphagen System
Depends on regulatory enzyme Regulatory enzyme is creatine kinase
(CK)
Factors affecting CK include
– [ATP] – [ADP]
Capacity and Power of Phosphagen System
Capacity – 1 mole (The capacity is limited by the muscle storage of phosphocreatine)
Power – 4 moles / minute
Diet and anaerobic training exercise increases phosphocreatine and frees their expansion
Types of Exercise Supported by Phosphagen System
Jumping
Sprinting
Throwing Events in Track and Field Weightlifting and Powerlifting
Hitting and Throwing in Baseball/Softball
Summary of Phosphagen System
Provides energy for activities lasting from 10 to 15 seconds
It is somewhat important for activities lasting 30 to 90 seconds
It does not contribute heavily to activities lasting more than 90 seconds
Creatine Supplementation
Creatine supplementation (e.g., 20 g/day) increases PCr concentrations in the muscle
Increased strength, hypertrophy, and delay of fatigue have been reported
Anecdotal reports of side effects include nausea, gastrointestinal distress, and cramping
Long-term negative effects are unknown
Lactic Acid System
Anaerobic glycolysis; Fast glycolysis
Anaerobic
Uses only carbohydrates (glucose) to form ATP Occurs in cytoplasm
Moderate power, moderate capacity
This system existed on earth before oxygen existed on earth (“billions” of years old)
Slower than the phosphagen system
Makes more ATP but it does it slower
Glycolysis
The stepwise, enzymatically- controlled degradation of glucose (a 6 carbon carbohydrate molecule) that leads to either:
– two pyruvic acid molecules (10 steps),
– two lactic acid molecules (11 steps)
The result is the transfer of energy from glucose to rejoin ADP and Pi (formation of ATP)
