Exam #1 Vocabulary Flashcards
Bioenergetics
the study of biological energy conversion
- the body needs to be able to convert energy to a usable form (ATP)
Monosaccharides
the simplest form of a sugar that makes up the building blocks of disaccharides and oligosaccharides
- glucose, fructose, galactose
Disaccharides
“double sugar,” two monosaccharides are joined by a glycosidic linkage
- lactose: galactose and glucose
- maltose: glucose and glucose
- sucrose: glucose and fructose
Dehydration Synthesis
A reaction that involves the loss of a water molecule when two molecules join together via a glycosidic linkage
- occurs when two monosacchardies are joined together to form a larger dissacharide
Hydrolysis
A reaction that involves the breakdown of a compound with the help of a water molecule
- occurs when a disaccharide is broken down to two simplier monosaccharides
Starch
A digestable polysaccharide that is stored in the small intestine and has nutrient value
- examples: pasta, potatoes, wheat rice
Fiber
An indigestable polysaccharide that is stored in the small intestine and does not have nutrient value
- examples: veggies, fruits, nuts, grains
Triglyceride
The main constituent of fats made up of one molecule of glycerol and three fatty acid chains
Creatine Phosphate
A chemical compound found predominantly in skeletal muscle where it stores phosphate to be used for short-term energy production
Adenosine Triphosphate (ATP)
A organic, high-energy compound that is the major source of energy for the body
- Nucleobase (adenine) + a ribose sugar + three phosphate group
Exergonic Reaction
a reaction that occurs spontaneously and therefore favorably, releasing energy in the process
- example: ATP hydrolysis
- mechanism: ATP + H2O –> ADP + Pi + free energy
Endergonic Reaction
a reaction that does not occur spontaneously, and it uses energy in the process
- example: step 1 in glycolysis takes energy to add a phosphate group to glucose, which is coupled to ATP hydrolysis to make it spontaneous “coupling mechanism”
Q10 effect
physiological phenomenon in which a 10ºC increase in temperature leads to a doubling of the reaction rate
- why warming up is super important –> it increases efficiency of aerobic metabolism by allowing O2 and Hb to bind more productively
Aerobic Metabolism
type of metabolism that requires O2 and occurs in the mitochondria
- example: Krebs/TCA cycle and oxidative phosphorylation
Anaerobic Metabolism
type of metabolism that can take place without O2
- example: glycolysis
Metabolism
Conceptual: sum of all energy converting/exchanging reactions in the body
Operational: rate of heat production by the body (kcal/min) which we can measure using calorimetry
Direct Calorimetry
measurement in a closed system of the total energy expended by directly measuring the heat produced
- Pros: very accurate
- Cons: expensive, difficult to operate, not ideal, only valid if all heat produced is actually released
Indirect Calorimetry
measurement in an open system of an individual’s energy expenditure by measuring air during an aerobic activity
- Pros: reliable during rest and exercise
- Cons: anaerobic metabolism is ignored and doesn’t perfectly reflect cellular metabolism
Respiratory Quotient (RQ)
VCO2 / O2 at the cellular level
Respiratory Exchange Ratio (RER)
VCO2 / O2 at the systematic/whole body level
- aka “non-protein RQ” because it is not possible to measure ATP production from proteins
- value increases with increasing exercise intensity as more CO2 is blown off
Calculation for Percent Fat Utilization
(1.0 - RER) / 0.3 * 100
Calculation for Percent Carbohydrate Utilization
100 - %Fat
Caloric Equivalent of O2
amount of kilocalories expended per liter of O2 consumed
- values on provided table: trace RER to its caloric equivalent in kcal/LO2 consumed
VO2
oxygen consumption (L/min)
- expressed graphically as %VO2, which refers to exercise intensity
Energy
the capacity to do work (kcal)
Work
Force (N) * distance (m)
- expressed as Nm, kcal, or joules
Power
rate at which work is performed (watts, Nm/s, or J/s)
- P = work/time
Ergometry
a form of measurement used to quantify work or power output during exercise
- caloric equivalents can be found using provided conversions
- two forms: cycle ergometry and treadmill ergometry
Calculating Ergometry
(1) find force (F = ma)
- m = resistance of flywheel (cycle) or mass of subject (treadmill)
(2) find distance
- cycle: d = d in revolutions/min * total time
- treadmill: d = belt distance in m/min * minutes / % grade
(3) find work (W = Fd)
(4) find power (P = W/t)
Mechanical Efficiency
percent of energy expended that appears as external work and is influenced by biomechanical skill, fiber type, exercise type, and resistance
- calculation: (caloric equivalent of P in kcal/min) / (rate of energy expenditure in kcal/min) * 100
- usually between 20-25%
Glycolysis
anaerobic cellular respiration in which, at its most basic level, one molecule of glucose is broken down to two pyruvate molecules
Glycogenesis
synthesis of glycogen from many molecules of glucose
Glycogen Synthase
the main enzyme in glycogenesis that converts G6P to glycogen
- ATP inhibits glycogen synthase
Glycogenolysis
breakdown of glycogen to glucose
Glycogen Phosphorylase
enzyme in glycogenolysis that re-synthesizes G6P from glycogen
Gluconeogenesis
synthesis of glucose from certain amino acids or other carbon skeletons
Oxidation Reaction
reaction that loses elections and H+ in the product and gains oxygen atoms
Reduction Reaction
reaction that gains elections and H+ in the product and C-C bonds
Hexokinase
first glycolytic enzyme that converts glucose to G6P
Phosphofructokinase (PFK)
rate-limiting enzyme of the glycolytic pathway that ultimately forms the pyruvate products in slow-acting glycolysis
- high AMP/ADP levels promote PFK
Stage 1 of Glycolysis
INVESTMENT STAGE
(1) hexokinase reaction
(2) isomeric rearrangement (G6P to F6P)
(3) PFK reaction
(4) splitting of F-1,6,-BP to DHAP and 2 molecules of G3P
Stage 2 of Glycolysis
ATP YIELDING STAGE
(1) oxidation of 2 G3P molecules
(2) phosphoglycerate kinase reaction
(3) pyruvate kinase reaction
4 ATP yielded per glucose molecule
LDH Reaction
chemical reaction in which lactate dehydrogenase (LDH) catalyzes the reversible oxidation of lactate to form pyruvate, with the help of election carrier NAD+
Pyruvate Kinase
glycolytic enzyme that catalyzes the very last step in glycolysis (PEP to pyruvate) and generates a second ATP molecule in the second stage of glycolysis
- transfers phosphate group from PEP to ADP, forming ATP
LDHh
isoform of lactate dehydrogenase with LOW affinity for converting pyruvate to lactate
LDHm
isoform of lactate dehydrogenase with a HIGH affinity for converting pyruvate to lactate
Pyruvate Dehydrogenase (PDH) Reaction
aerobic reaction that occurs in the mitochondria of the cell
- pyruvate is decarboxylated to form acetyl-CoA, NADH, and CO2
Acetyl-CoA
molecule that can participate in protein, carbohydrate, and lipid metabolism
Krebs/TCA Cycle
aerobic cycle that occurs in the matrix of the mitochondria yielding NADH and FADH2 for oxidative phosphorylation
- products: 1 ATP, 3 NADH, 1 FADH, 2 CO2
Electron Transport Chain
site of oxidative phosphorylation within the inner mitochondrial membrance which is made up of a series of complexes that undergo redox reactions to couple election transfer with the transfer of protons from the matrix to the intermembrance space
- protons are used to power ATP synthase to produce high yields of ATP
Oxidative Phosphorylation
process by which ATP is formed with the help of electron transfer from NADH and FADH2 to oxygen by a series of electron carriers
- produces the most ATP from glucose metabolism
- generates between 30-32 ATP from 1 glucose molecule
Glycerol/Phosphate Shuttle
shuttle system that oxidizes NADH to NAD+ with the help of DHAP in its reduction to G3P which CAN cross the mitochondrial membrane and carry NADH’s original elections along with it
- when G3P is inside the mitochondria, it can be oxidized back to DHAP and FADH is reduced to FADH2 for use in the ETC
- yields 1.5 ATP per FADH2
Malate-Aspartate Shuttle
shuttle system that oxidizes NADH to NAD+ with the help of OAA in its reduction to malate which CAN cross the mitochondrial membrane and carry NADH’s original electrons along with it
- when malate is inside the mitochondria, it can be oxidizes to OAA again and NAD+ is reduced to NADH for use in the ETC
- yields 2.5 ATP per NADH
