IB SEHS Option D

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