Mitsouras - Intro to Metabolism and Nutrition

Question 1

what is dietary fiber

Answer 1

non- digestible, non-starch carbohydrate and lignin with NO energy yield and excreted in feces

Question 2

what is an adequate intake of dietary fiber for men and women

Answer 2

men: 38 g/day and females: 25 g/day (US diets have about 15 g/day)

Question 3

what 3 diseases/conditions does dietary fiber reduce the risk for

Answer 3

diverticulitis, colon cancer and carcinogens, and cardiovascular disease

Question 4

what are micronutrients

Answer 4

vitamins, minerals, other trace elements that cannot be synthesized by our bodies and are required for a variety of cell processes (small amounts needed)

Question 5

what are 4 uses for micronutrients- vitamins

Answer 5

enzyme cofactors, antioxidants, ligands for hormone receptors and other functions

Question 6

what is an example of a use for micronutrient-minerals and trace elements

Answer 6

biological processes like bone mineralization to cellular transport

Question 7

what are macronutrients

Answer 7

carbohydrates, proteins, fats, and alcohols that are oxidized for energy/calories (needed to larger amounts)

Question 8

what are carbohydrates needed for

Answer 8

(4 cal/g) mono-, di-, and polysaccharides for energy production

Question 9

what are proteins needed for

Answer 9

(4 cal/g) amino acids (essential and non-essential) for protein synthesis and carbons for glucose synthesis

Question 10

what are fats needed for

Answer 10

(9 cal/g) saturated, unsaturated, mono and polysaturated for energy production of fat soluble vitamins, prostaglandin synthesis and components of cell membrane

Question 11

what is AMDR (acceptable macronutrient distribution ranges)

Answer 11

help reduce risk of chronic disease: fats 20-30%, proteins 10-35% and carbs 45-65% of total daily calories

Question 12

what is EAR (estimated average requirement)

Answer 12

average daily intake adequate for 50% of individuals in specific life stages and gender group

Question 13

what is RDA (recommended dietary allowance)

Answer 13

average daily intake adequate for 97% of individuals in specific life stage and gender group

Question 14

what is adequate intake (AI)

Answer 14

estimated range of intake when RDA or EAR cannot be established due to insufficient scientific evidence

Question 15

what is tolerable upper level intake (UL)

Answer 15

highest average daily intake with NO adverse effects to almost no individuals (intake above UL the risk increases)

Question 16

what is the resting metabolic rate (RMR)

Answer 16

energy expenditure of resting, post-absorptive individual over 24 hr period (calories needed for basic life functions) affected by age, gender, body temp, and thyroid function

Question 17

what is the thermic effect of food (TEF)

Answer 17

the energy expended to process/digest food

Question 18

what is the total energy expenditure (TEE)

Answer 18

total energy expended over 24 hours (TEE = RMR +TEF + physical activity)

Question 19

what happens if the TEE is equal to the calorie intake

Answer 19

energy balance - weight is maintained

Question 20

what happens if TEE is greater than the calorie intake

Answer 20

body uses stored energy to make up difference = weight loss

Question 21

what happens if TEE is less than the calorie intake

Answer 21

body stores excess = weight gain

Question 22

what are the 2 ways the body stores excess

Answer 22

in adipose tissue and muscle and liver

Question 23

what is stored in adipose tissue

Answer 23

fatty acids and carbs –> TAG’s (triacylglceride): lower H2O when stored, unlimited supply/storage and more kcal when stored

Question 24

what is stored in muscle and liver

Answer 24

glycogen (24 hr supply), higher H2O, and fewer kcal/g when stored

Question 25

what is BMI

Answer 25

measure of body fat based on height and weight that applies to adult men and women.

Question 26

what is the BMI equation

Answer 26

BMI = weight (kg) / height (m)2

Question 27

what is the range for normal BMI

Answer 27

18.5-24.9

Question 28

what underweight BMI

Answer 28

under 18.5

Question 29

what the overweight BMI

Answer 29

25-29.9

Question 30

what is obese BMI

Answer 30

over 30

Question 31

what other factors besides BMI do you consider when diagnosing obesity

Answer 31

waist circumference/abdominal fat, high blood pressure, and physical inactivity

Question 32

what is metabolism

Answer 32

sum of chemical and physical changes- goal is energy production and synthesis of macromolecules

Question 33

what are the 2 processes for metabolism

Answer 33

anabolism and catabolism

Question 34

what is anabolism

Answer 34

biosynthesis (building) and energy input is required

Question 35

what is catabolism

Answer 35

breakdown of dietary nutrients and yields energy

Question 36

what are 3 properties of metabolic pathways

Answer 36

reactions are linked into pathways, pathways are linked to other pathways and coupling (combining energetically favored pathways or reactions)

Question 37

what is Gibbs Free Energy

Answer 37

a way to determine if a reaction and/or pathway is going to be spontaneous or not

Question 38

what is the Gibbs free energy equation

Answer 38

∆G0 = RT(lnKeq)

Question 39

what happens if ∆G0 is less than 0

Answer 39

spontaneous reaction

Question 40

what happens if ∆G0 is greater than 0

Answer 40

non-spontaneous reaction

Question 41

what happens if spontaneous and non-spontaneous reaction are coupled together

Answer 41

Energy from ∆G0 < 0 drives ∆G0 > 0

Question 42

what does ATP do in metabolic pathways

Answer 42

acts as an energy storage molecule with high energy phosphate bonds "energy carrier"

Question 43

what happens to ATP in the catabolic pathway

Answer 43

it synthesizes ATP and produces energy

Question 44

what happens to ATP in the anabolic pathway

Answer 44

it hydrolyzes ATP --> ADP or AMP

Question 45

what metabolic pathway has low ATP

Answer 45

catabolism pathway

Question 46

what metabolic pathway has high ATP

Answer 46

anabolism pathway

Question 47

what is the effect of allosteric enzymes on metabolic pathways

Answer 47

fast, transient changes, short range, positive or negative effects, and allows enzymes to respond to intracellular signals and conditions (effector can be substrate or product in same pathway)

Question 48

where do allosteric enzymes bind to

Answer 48

sites different from active site

Question 49

are allosteric enzymes single or multi subunits

Answer 49

almost always multi-subunit

Question 50

what are 2 types of allosteric regulation

Answer 50

feed-forward stimulation and feed-back inhibition

Question 51

what is feed- forward stimulation

Answer 51

drives the reaction forward, fast and short range

Question 52

what is feed-back inhibition

Answer 52

inhibits the reaction, fast and short range

Question 53

what is the effect of induction and response hormone mechanisms on metabolic pathways

Answer 53

slower, permanent changes, long range effects, mediated by hormones, and allow cell to respond to extacellular signals

Question 54

what is the effect of covalent mechanisms on metabolic pathways

Answer 54

fast, transient changes, long range effects, positive or negative effects, allows cell to respond to extracellular signals, and phosphorylation/dephosphorylation

Question 55

what is a committed step

Answer 55

the first irreversible step that is unique to the pathway

Question 56

is the enzyme catalyzing the committed step regulated or unregulated

Answer 56

regulated

Question 57

what 2 things regulate metabolism

Answer 57

substrate availability and accessibility and enzyme acitivity