Chapter 5: Essentials of Metabolism Flashcards
Metabolism
processes in which food is converted into fuel (converted through kinetic and potential energy)
Kinetic - energy used for work
Potential - energy stored for later (through adipose tissues and in our liver as glycogen)
Thermic Effect of Food
the energy expenditure of food we eat (overall 10% contribution of total daily energy requirements)
ATP (Adenosine triphosphate)
unit of energy (human energy currency) chemical compound is adenine (base) + sugar molecules + 3 phosphate bind by oxygen molecules
Thermodynamics
Bioenergetics
Conservation of energy
law that energy can’t be created or destroyed but only to be conserved
kinetic energy
energy during movement
enzymes
catalysts that accelerate chemical rxn
reactant
substance consumed during chemical rxn
enthalpy
sum of the system’s internal energy and the product
entropy
the energy that gets released by chemical rxn (its value changes depending on the amount of matter that’s present)
calorie/joule
unit of energy changes (calories x 4.184) = joule
hydrolysis
breakage of bonds between the three phosphate molecules (these happen and energy is used up) and become diphosphate
myosin
work together with actin for muscle contraction (protein of muscle)
Myosin is the prototype of a molecular motor—a protein that converts chemical energy in the form of ATP to mechanical energy, thus generating force and movement.
actin
work together with myosin for muscle contraction
Sliding filament theory
a theory that describes that actin and myosin bind/work together for muscle movement & contraction
**Myosin reaches forward, binds with actin, contracts, releases –> creates energy/movement
ATPase
Enzyme responsible for the hydrolysis of ATP –> Products are ADP and a free phosphate
Exergonic
energy releasing (negative energy)
How many calories/joules are created/released during a single hydrolysis of ATP?
7.3 CALORIES/30.5 KJ
What are the 3 ways that we use fuel resources to create energy?
The 3 main energy systems are
- ATP - PCr (phosphocreatine system)
- anaerobic glycolysis
- oxidative phosphorylation
Describe the ATP Resynthesis process and the phosphocreatine shuttle process
Phosphocreatine shuttles describes how ATP is resynthesized by enzyme, CK. The product can be ADP + phosphate molecule and/also Creatine. This creates short bursts of energy. But also the resulting creatine can be used/shuttled to mitochondria during aerobic activity which then is again processed by enzyme mitochondrial CK that is resynthesizes to creatine phosphate (PCr)
Isoform
highly similar proteins that originate from a single gene or gene family
Cytosol
the water soluble components of cell cytoplasm, constituting the fluid portion that remains after removal of the organelle and other intracellular structures. (Creatine kinase from turning ATP into ADP)
Isoenzyme
a group of enzymes that catalyze the same rxn but have different enzyme forms and catalytic efficiencies - often found in different parts of the body
Glycolysis
the pathway that converts glucose into pyruvate
pyruvate
important molecule at the intersection of multiple biochemical pathways
GLUT4
glucose transporter found in adipose, skeletal, and cardiac tissue - glucose is transported through GLUT4 and converted into G6P.
Glycogenolysis
breakdown of glycogen
**Glycogen must be first broken down to release its glucose molecules (catalyzed by the enzyme glycogen phosphorylase)
Steps of Glycogen conversion into ATP
Glycogen is broken down and releases glucose molecules (process known as glycogenolysis). the result is G1P which then is converted into G6P, which becomes available for energy.
Adrenaline
Adrenal medulla
Describe the process in which glycogenolysis process is activated in our body
- Detecting physiological stress in our body
- Adrenaline release
- receptor
- activated proteins (relaying messages to initiate events)
- Activation of glycogen phosphorylase (enzyme that breaks down the glycogen, releasing glucose)
