IB SEHS - Option D
trypsin
breaks down proteins (small intestine)
pepsin
breaks down proteins (stomach)
Basal metabolic rate Thermic effect of feeding Thermic effect of physical activity
components of daily energy expenditure
bile salts
emulsify fats, spreading them out to increase surface area (also "presents" the fats to the villi so that lipase can begin decomposition process)
denaturation
enzymes lose shape because of temperature or PH imbalance
creatine
gaining muscle, aids the synthesis of creatine phosphate; benefits exercise that uses ATP-PC energy system
lipids
harder to digest because of hydrophobic nature
weight gain liver and kidney damage (where excess proteins are processed) high cholesterol
harmful effects of excessive protein intake
carbo-loading
high GI foods provide a supply of glycogen (for energy/ATP)
Thirst Urine color (pale apple juice) Urine osmolarity (more solutes, lower freezing point) Specific gravity (hydrometer) Change in body mass (not more than 2%)
how athlete hydration can be monitored.
protein
important for building and repairing cells (muscle) following endurance or shorter events
hypothalamus
main monitor of fluid level in blood (blood gets thick if without) in brain
low GI foods
may be beneficial prior to exercise; daily diet should be low to medium GI carbohydrates
absorption
movement of small particles across gastrointestinal tissue (stomach (lil), SMALL INTESTINE, LARGE INTESTINE)
fructose
moves by facilitated diffusion (uses a channel (high to low))
slow twitch
needs more fat for fuel
5.5 - 7.5
pH of mouth
6-8
pH of pancreas
6-8
pH of small intestine
1-4
pH of stomach
mechanical digestion
physical breakdown of big pieces to small (mouth, stomach)
1.2 to 1.4 g/kg/day
protein intake for endurance athletes
1.2 to 1.7 g/kg/day
protein intake for strength athletes
enzymes
proteins that decrease activation energy and speed up chemical reactions
sports drinks, bars, and gels
provide a lot of energy but only necessary for extremely intense activity
carb loading
reducing training and increasing carbohydrate intake (avoids need for hard exercise to empty muscles of glycogen) → greater energy store, longer performance
elimination
release of waste, undigested food (rectum, anus)
hyponatremia
sodium(NaCl) concentration is too low, water concentration too high; variety of causes possible
fish, chicken, red meats
sources of protein for non-vegetarians
cheese, eggs, nuts
sources of protein for vegetarians
caffeine
stimulates the nervous system (higher heart rate), can increase blood flow to exercising muscles, increases short-term force, boost mid-event
increase the rate of digestion whilst maintaining a stable body temperature
the function of enzymes in the context of macronutrient digestion
break down food so that the organism can absorb it.
the need for enzymes in the context of macronutrient digestion
Loss of water and salt from sweat Electrolytes enhance fluid absorption in the gut. Glucose in drinks provides energy source
the reasons for adding sodium and CHO to water for endurance athletes
0.8 per kg of body weight
the recommended daily intake of protein for adult female and male non-athletes
Intake occurs intermittently during the day, expenditure occurs constantly Energy balance: overconsumption of food will lead to storage → weight gain Insufficient consumption of food will lead to compensation for deficit → weight loss
the relationship between energy expenditure and intake
low intensity exercise (endurance)
type 1 (slow twitch) fibers will be used; synthesis of ATP will be aerobic/Krebs cycle.
2.5 L
typical daily water loss from urine, sweat, saliva, feces, etc.
urine
urea and uric acid; gets rid of nitrogenous waste and salts to keep blood volume correct
high intensity exercise (burst of energy needed)
uses fast twitch fibers, anaerobic metabolism, glycolysis will demand high rates of glycogen.
Athletic training causes a loss in water weight and body fat (muscle tissues are more watery)
water distribution in trained individuals
peristalsis
wave movement contraction along gastrointestinal tract (Esophagus → rectum)
weight reduction
(boxers; jockeys) restrict fluids & food to fit into a weight class → dangerous as it can cause dehydration
high GI foods
(post-exercise) assist the body in restoring its glycogen stores → re-fueling, or during exercise
calorie-dense foods
Brain has a drive to consume them Beneficial if amount of food available is more scarce
Antidiuretic Hormone (ADH)
Causes retention of water in kidneys Received in the collecting duct of nephron
rate of glycolysis will be low
Continuous moderate exercise (cycling) in slow twitch muscle fibers
Carb Loading Protein consumption for gaining muscle mass (FFM) Reduction of energy intake for reducing fat mass Deliberate restriction of food and fluid to achieve a body mass that allows them to compete in a specific weight class → causes dehydration and low energy stores
Discuss dietary practices employed by athletes to manipulate body composition.
BMI
Doesn't take muscle into account
40
During a fast, can lose only __% of body weight without dying
Amount of physical activity How frequently you eat (process of digesting food takes energy) How much you eat Body size Body composition (fat tissue doesn't need a lot of energy, lean (muscle) tissue is very active)
Factors that increase daily energy needs
medium glycogen content
Fast twitch (type IIa)
high glycogen content
Fast twitch (type IIb)
urine production
Filtration - capsule Reabsorption - pct/henle Secretion - dct
High: (sweets) = 100 Medium: (brown rice) = 50 Low: (green vegetables) = > 15
GI
transport/absorption
Glucose and the other monosaccharides cross at brush border, through cytoplasm (cytosal) of the basolateral membrane and into the capillary
hydrostatic weighing
Gold standard, more accurate/reliable Complicated equipment Have to be comfortable with water Affected by ability to immerse yourself
nutrient-dense foods
Healthy Lots of micronutrients and macronutrients
rate of glycolysis will be high
High intensity exercise (sprinting) in fast twitch fibers
Water: 3-4 days Food: 30-60 days
How long without food and water (depending on conditions)?
water
Medium in which metabolic processes occur Regulates body temperature Enables movement of substance around body Allows for exchange of nutrients and products
basal metabolic rate (BMR)
Minimum amount of energy needed to survive
fat
Most energy can be produced from ______ (most useful macronutrient)
glycemic index (CI)
a number associated with the carbohydrates in a particular type of food that indicates the effect of these carbohydrates on a person's blood glucose level
skinfold calipers
Pinch Less precise → how well squeeze is Harder for overweight people More invasive
amino acid structure
Proteins are absorbed at the same place through varied mechanisms depending on ________________
bioelectrical impedance
Scales that send weak current through body and times how fast it can go through you (more fat = slower) +/- 3.5% Consistent calculation and machinery Very affected by hydration More private
DXA
Scans body Extremely accurate Expensive equipment
low glycogen content
Slow twitch (type I)
glucose and galactose
actively transported (requires energy, low to high)
bicarbonate
alkaline/base which increases pH of blood which increases tolerance of lactic acid during exercise
Obvious differences in body compositions among different sports: Endurance athletes = slender and small Strength and power athletes = muscular
association between body composition and athletic performance
chemical digestion
breakdown at molecular level so that absorption can occur (Mouth (lil), Stomach (lil), Pancreas (producing enzymes), SMALL INTESTINE)
salivary amylase
breaks down carbohydrates (oral cavity)
pancreatic amylase
breaks down carbohydrates and fats (small intestine)
bile
breaks down fats (small intestine (not pancreatic lipase))
pancreatic lipase
breaks down fats (small intestine)
interstitial (between cells but in tissue), plasma, saliva, lymph, tears, digestive tract, CSF (brain, nerve cord fluid), sweat, urine, exhale
where extracellular fluid can be located in the body
water used for thermoregulation during exercise → higher need for water replenishment
why endurance athletes require greater water intake