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