Unit 3-Energy, Exercise, and Body Weight//Unit 4- Water, Electrolytes, and Contaminants Flashcards
Unit 3: Energy, Exercise, and Body Weight
Universal currency of energy = ____
WHY do we need energy?
• To perform mechanical work
– Muscle contraction, cellular movement
• _____ ________of molecules and ions across
biological membranes
• Synthesis of _____________ from simple
precursors
ATP
Active transport
macromolecules
Unit 3: Energy, Exercise, and Body Weight
ATP Is the primary donor of ____ ______ for metabolic and other biochemical reactions
• ATP turnover is very high in the body; each molecule lasts about a minute before being consumed
• The total amount in the body is ~100g, however strenuous exercise consumes ______/MIN
• ATP regeneration must therefore be highly efficient!
–Carbon-containing fuel molecules like glucose or fats, are oxidized to CO2 and the energy release is used to convert ___ & _____ to ATP
free energy
~500g/min
ADP and PI
Unit 3: Energy, Exercise, and Body Weight
Energy from food is extracted in three stages
———— Stage 1:————————
• Large, complex molecules are broken down into usable units
• Fats are broken down to fatty acids and glycerol
• Polysaccharides are processed to glucose and other simple sugars
• Proteins are hydrolyzed to amino acids
• No energy is generated here!!!
STAGE ONE IS BASIC BUT KNOW….
No energy is generated here!!!
Unit 3: Energy, Exercise, and Body Weight
————–Stage 2:————————–
• Numerous small carbon compounds are degraded to a
common end product – ____________
• Some energy (ATP) is generated in this step, but some is also _________
Acetyl CoA
consumed
Unit 3: Energy, Exercise, and Body Weight
———————Stage 3:——————————–
• The acetyl group of acetyl CoA is completely oxidized to ______
•__________ are released, captured by intermediates (NAD+ and FAD), and used to power a proton
gradient that synthesizes large amounts of ATP
CO2
Electrons
Unit 3: Energy, Exercise, and Body Weight
The function of the citric acid cycle is to accept 2-carbon
fragments and ________ them to CO2
• This produces high-energy electrons that are then used to reduce molecular oxygen (O2) to water.
• Electrons are accepted by ____ &_____ to form NADH and FADH2
oxidize
NAD+and FAD
Unit 3: Energy, Exercise, and Body Weight
Energy Requirements = Dietary Energy Intake
• Required for growth or __________ in a person of
defined age, gender, weight, height, and physical activity
• In pregnant and lactating women, it includes the needs for deposition of tissue and production and secretion milk
• An ___OR_____ person needs may be increased or
decreased
maintenance
ill or injured
Unit 3: Energy, Exercise, and Body Weight
——-Total Energy Expenditure (TEE) or
Estimated Energy Requirement (EER)—————-
1—_____ _________ ______________ (BEE)
= _________ energy expenditure compatible with life
– Reflects the energy used over a 24 hour period while physically and mentally at REST and in a thermoneutral environment
– Measurement should be taken after sleep and 10-12 hours post-prandial
– ___% TO ____% of total energy expenditure (TEE)
Basal energy expenditure
Minimal
60% to 70%
Unit 3: Energy, Exercise, and Body Weight
——-Total Energy Expenditure (TEE) or
Estimated Energy Requirement (EER)—————-
2—_______ __________ OF ________ (TEF)
– Energy needed for consumption, digestion, and absorption of FOOD
– Accounts for about ____% of TEE
– Obligatory includes synthesis and storage
– Facultative thermogenesis is excess energy expended
– Affected by ____________ of the diet, eating schedule, and spices
Thermic effect of FOOD
10
composition
Unit 3: Energy, Exercise, and Body Weight
——-Total Energy Expenditure (TEE) or
Estimated Energy Requirement (EER)—————-
3—-__________ __________ (AT)
– Energy expended during sports or fitness exercise and activities of daily living
– Most variable component of ___
– Affected by body size, efficiency of individual habits of motion, and ______ _________
Activity thermogenesis
TEE
fitness level
Unit 3: Energy, Exercise, and Body Weight
Factors Affecting Resting Energy Expenditure (REE)
REE is used in place of BEE most often today, and are often used interchangeably. REE is usually __-___% higher than BEE.
Body size (direct prop)
• Body composition (direct prop with LBM)
• Age (indirect prop)
• Gender (M>W, 5-10%)
• Hormonal status
• Caffeine, nicotine, and alcohol (increases REE)
• Fever (increases REE by 7% per °F over 98.6 °F)
• Extreme environmental temperatures
***REE is measured using ______ ________ through the use of a ventilated hood system
10-20%
indirect calorimetry
Unit 3: Energy, Exercise, and Body Weight
Units of Energy Measurement • Kilocalorie (kcal)-----------1 kcal = \_\_\_\_\_\_ kj – Carbohydrate = 4 kcal/g – Protein = 4 kcal/g – Fat = 9 kcal/g – Alcohol 7 kcal/g
Kilojoule (kJ)—non–U.S. countries; the metric value
1 kj = energy req. to move 1 kg a distance of 1 m (using a force of 1 N)
– Carbohydrate = 17 kJ
– Protein = 17kJ
– Fat = 38 kJ
4.18
Unit 3: Energy, Exercise, and Body Weight
Measuring Energy Expenditure
1 •_____ calorimetry
– Measures amount of heat produced by the individual
– Very expensive!
2 • _______calorimetry
– Used in clinical practice, particularly in intensive care and burn units
– Equipment is known as metabolic cart or monitor
– Provides information on substrate utilization through the respiratory quotient (RQ)
3 • Doubly labeled water
– Using radiolabeled water,_____ production is measured, and then equated to TEE
Direct
Indirect
CO2
Unit 3: Energy, Exercise, and Body Weight
____ = Volume of CO2 EXPIRED/volume of O2
CONSUMED to metabolize a particular molecule
RQ values:
>1.0 = fat synthesis
1.0 = carbohydrate
0.85 = mixed diet
0.82 = protein
0.7 = fat
0.67 = alcohol
RQ
macronutrient(s)
Unit 3: Energy, Exercise, and Body Weight
_____ _____ ______= (TEE)
Age, weight, height and PA are the only variables
HEIGHT = METERS WEIGHT = KILOGRAMS AGE = YEARS PA = coefficient
Total Energy Expenditure
Unit 3: Energy, Exercise, and Body Weight
Macronutrients are __________
-produces energy when metabolized
ergogenic
Unit 3: Energy, Exercise, and Body Weight
———4 Focal Points————–
1 • Metabolic rate in the human body is affected by several variables, including daily TEE, two-thirds of which is the ______
2 • The energy cost of physical activity is the most variable of factors related to an individual’s______ and can be altered by the individual.
3 • Energy expenditure can be measured by several methods, but only ________calorimetry provides an RQ.
4 • Energy expenditure equations are commonly used with an activity factor to estimate energy needs.
BEE.
TEE
indirect
Unit 3: Energy, Exercise, and Body Weight
How much Carbs, Protein and Fat should you eat? Example: your TEE is 2,500 kcal/day 1----Percentage of kcal from Carbs: 60% Protein: 10% Fat: 30% Alcohol: 0 2---Atwater Coefficient--- CARBS--4.0 kcal/g PROTEIN--4.0 FAT--9.0 ALCOHOL--7.0 3---Carbs: (2500 kcal/day x 0.60)/4 kcal/g = 375 g/day Protein: (2500 x 0.10)/4 = 62.5 g/day Fat: (2500 x 0.30)/9 = 83.33 g/day
KNOW
Unit 3: Energy, Exercise, and Body Weight
Desirable Body Weight or Optimum Body Weight
1–• Balancing energy intake and energy expenditure
is the basis of ______ __________ throughout
life.
2—Intake > Expenditure = Normal growth, pregnancy,
obesity, recovery from illness, HYPOthyroidism
• Intake = Expenditure = Normal condition of healthy
adults
3–• Intake
weight management
diabetes mellitus and malabsorption
Unit 3: Energy, Exercise, and Body Weight
Theoretical Body Composition Model for a Man and Woman
1—Essential body fat—Necessary for physiologic
function. About ___% of body weight in men and __% in women
2–Storage body fat—Energy reserve under the skin,
primarily triglycerides in adipose tissue. Around the internal organs to protect them from trauma. Most considered expendable.
Good health associated with:
____-_____% of body weight in MEN
_____-______% in WOMEN
3
12
10% to 25%
18% to 30%
Unit 3: Energy, Exercise, and Body Weight
Body Mass Index (BMI)
• BMI = weight / height2 (kg/m2)
• General comparison between body wt and _____
BMI RANGE FOR MEN AND WOMEN 18.5 – 24.9 Normal 25 – 29.9 Overweight 30 – 34.9 Obese 35+ Clinically obese
health
Unit 3: Energy, Exercise, and Body Weight
Methods of Measuring Obesity 1 • BMI-----------Know the cutoffs!! 2 • Waist circumference: > \_\_ inches in men > \_\_ inches in women 3 • Waist-to-hip Ratio (WHR): > 0.85 in men > 0.73 in women ****Varies according to race and age. Older people are allowed higher WHR, younger less
40
35
Unit 3: Energy, Exercise, and Body Weight
Etiology of Obesity X 11
1 • Heredity—obesity gene? Twins show genetic component
2 • Imbalance of intake versus output
3 • Lack of exercise
4 • Sleep, stress, and circadian rhythms
– Chronic sleep deprivation
– Cortisol
5 • Set point Theory:body maintains its normal weight and body fat level with internal regulatory controls that dictate how much fat one has!!
6 • Thermic Theory: low level of brown adipose tissue. Less futile cycles into heat
7 • Psychological: tendency to eat when depressed
8 • Adipocyte Theory:_______ obesity increases adipocyte number!!
9 • Socioeconomic: Affordability and availability of food
10 • Cultural: Feasting, etc
11 • Lifestyle: Snacks, football Sunday, etc
Infant
MOST IS COMMON SENSE
Unit 3: Energy, Exercise, and Body Weight
Etiology of Obesity: Set point Theory
• Idea: The body has a mechanism to regulate its fat
size
• Evidence: Humans and animals can restore normal
body weight when allowed to eat freely after ________ OR_________.
• Mechanism: Unknown. Blood levels of a group of
peptides are being investigated for their effects on
appetite.
starvation or forced feeding.
Unit 3: Energy, Exercise, and Body Weight
Appetite Altering Peptides:Orexigenic Peptides Orexigenic: Peptides that INCREASE appetite
– Agouti-related peptide
– Neuropeptide Y
– Melanin Concentrating Hormone (MCH)
– Orexins (hypocretins)
ALL FOUR RELEASED BY ____________-
BRAIN
Unit 3: Energy, Exercise, and Body Weight
Appetite Altering Peptides:Orexigenic Peptides Orexigenic: Peptides that INCREASE appetite
– Insulin
RELEASED BY??
PANCREAS
Unit 3: Energy, Exercise, and Body Weight
Appetite Altering Peptides:Orexigenic Peptides Orexigenic: Peptides that INCREASE appetite
Ghrelin
RELEASED BY??
STOMACH
**Blood ghrelin is lowest after a meal, rises prior to next meal
Unit 3: Energy, Exercise, and Body Weight
Appetite Altering Peptides:Anorexigenic Peptides
Anorexigenic: Peptides that DECREASE appetite
– ______ ________: blocks ghrelin
– _______ ________: delays stomach emptying, acts on satiety center in brain
– Cholecystokinin
ALL RELEASED BY INTESTINE!!
Peptide YY
***Injection with Peptide YY decreases appetite in humans
Glucagon-like peptide
Unit 3: Energy, Exercise, and Body Weight
Appetite Altering Peptides:Anorexigenic Peptides
Anorexigenic: Peptides that DECREASE appetite
– Melanocortin: binding R inhibits intake
RELEASED FROM WHAT ORGAN??
BRAIN
Unit 3: Energy, Exercise, and Body Weight
Appetite Altering Peptides:Anorexigenic Peptides
Anorexigenic: Peptides that DECREASE appetite
Leptin: regulates intake of kcal, C, F, but not percentages of each. Does not prevent obesity!!!
RELEASED BY??
Adipocyte
Unit 3: Energy, Exercise, and Body Weight
Brain Neurotransmitters
• Norepinephrine and dopamine —released by sympathetic nervous system in response to dietary intake»_space;» mediates hypothalamus = _______ food intake
• Fasting and semistarvation decrease levels of
these neurotransmitters = __________ food intake
decreased
increased
Unit 3: Energy, Exercise, and Body Weight
OBESITY Health Risks and Longevity Diabetes • Heart disease • Hypertension • Hyperlipidemia • Gallbladder disease • Some cancers • Nonalcoholic fatty liver disease (NASH) • Atherosclerosis • Respiratory insufficiency & sleep apnea • Joint diseases / arthritis • Metabolic Syndrome
DON’T GET FAT!!
