Studied by 4 people
5.5 - 7.5
pH of mouth
1-4
pH of stomach
6-8
pH of pancreas
6-8
pH of small intestine
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
salivary amylase
breaks down carbohydrates (oral cavity)
pancreatic amylase
breaks down carbohydrates and fats (small intestine)
pancreatic lipase
breaks down fats (small intestine)
bile
breaks down fats (small intestine (not pancreatic lipase))
pepsin
breaks down proteins (stomach)
trypsin
breaks down proteins (small intestine)
water
Medium in which metabolic processes occur
Regulates body temperature
Enables movement of substance around body
Allows for exchange of nutrients and products
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
Athletic training causes a loss in water weight and body fat (muscle tissues are more watery)
water distribution in trained individuals
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.
water used for thermoregulation during exercise → higher need for water replenishment
why endurance athletes require greater water intake
basal metabolic rate (BMR)
Minimum amount of energy needed to survive
Basal metabolic rate
Thermic effect of feeding
Thermic effect of physical activity
components of daily energy expenditure
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
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
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.
carb loading
reducing training and increasing carbohydrate intake (avoids need for hard exercise to empty muscles of glycogen) → greater energy store, longer performance
low glycogen content
Slow twitch (type I)
medium glycogen content
Fast twitch (type IIa)
high glycogen content
Fast twitch (type IIb)
high intensity exercise (burst of energy needed)
uses fast twitch fibers, anaerobic metabolism, glycolysis will demand high rates of glycogen.
low intensity exercise (endurance)
type 1 (slow twitch) fibers will be used; synthesis of ATP will be aerobic/Krebs cycle.
rate of glycolysis will be low
Continuous moderate exercise (cycling) in slow twitch muscle fibers
rate of glycolysis will be high
High intensity exercise (sprinting) in fast twitch fibers
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
High: (sweets) = 100
Medium: (brown rice) = 50
Low: (green vegetables) = > 15
GI
high GI foods
(post-exercise) assist the body in restoring its glycogen stores → re-fueling, or during exercise
low GI foods
may be beneficial prior to exercise; daily diet should be low to medium GI carbohydrates
carbo-loading
high GI foods provide a supply of glycogen (for energy/ATP)
weight reduction
(boxers; jockeys) restrict fluids & food to fit into a weight class → dangerous as it can cause dehydration
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
sports drinks, bars, and gels
provide a lot of energy but only necessary for extremely intense activity
caffeine
stimulates the nervous system (higher heart rate), can increase blood flow to exercising muscles, increases short-term force, boost mid-event
creatine
gaining muscle, aids the synthesis of creatine phosphate; benefits exercise that uses ATP-PC energy system
bicarbonate
alkaline/base which increases pH of blood which increases tolerance of lactic acid during exercise
0.8 per kg of body weight
the recommended daily intake of protein for adult female and male non-athletes
cheese, eggs, nuts
sources of protein for vegetarians
fish, chicken, red meats
sources of protein for non-vegetarians
1.2 to 1.4 g/kg/day
protein intake for endurance athletes
protein
important for building and repairing cells (muscle) following endurance or shorter events
1.2 to 1.7 g/kg/day
protein intake for strength athletes
weight gain
liver and kidney damage (where excess proteins are processed)
high cholesterol
harmful effects of excessive protein intake
Water: 3-4 days
Food: 30-60 days
How long without food and water (depending on conditions)?
40
During a fast, can lose only __% of body weight without dying
2.5 L
typical daily water loss from urine, sweat, saliva, feces, etc.
hypothalamus
main monitor of fluid level in blood (blood gets thick if without) in brain
Antidiuretic Hormone (ADH)
Causes retention of water in kidneys
Received in the collecting duct of nephron
urine
urea and uric acid; gets rid of nitrogenous waste and salts to keep blood volume correct
urine production
Filtration - capsule
Reabsorption - pct/henle
Secretion - dct
hyponatremia
sodium(NaCl) concentration is too low, water concentration too high; variety of causes possible
mechanical digestion
physical breakdown of big pieces to small (mouth, stomach)
chemical digestion
breakdown at molecular level so that absorption can occur (Mouth (lil), Stomach (lil), Pancreas (producing enzymes), SMALL INTESTINE)
peristalsis
wave movement contraction along gastrointestinal tract (Esophagus → rectum)
absorption
movement of small particles across gastrointestinal tissue (stomach (lil), SMALL INTESTINE, LARGE INTESTINE)
elimination
release of waste, undigested food (rectum, anus)
enzymes
proteins that decrease activation energy and speed up chemical reactions
denaturation
enzymes lose shape because of temperature or PH imbalance
transport/absorption
Glucose and the other monosaccharides cross at brush border, through cytoplasm (cytosal) of the basolateral membrane and into the capillary
glucose and galactose
actively transported (requires energy, low to high)
fructose
moves by facilitated diffusion (uses a channel (high to low))
amino acid structure
Proteins are absorbed at the same place through varied mechanisms depending on ________________
lipids
harder to digest because of hydrophobic nature
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)
Amount of physical activity
How frequently you eat (process of digesting food takes energy)
How much you eat
Body size
Note 
Flashcard (20)