Exam 2 Metabolism Part 1

Question 1

What fraction of TEE is made up by resting energy expenditure (RMR)?

Answer 1

75%

Question 2

What is the primary determinant of RMR?

Answer 2

Lean body mass (fat free mass)

Question 3

Define thermic effect of food? Which foods have a high/low TEF?

Answer 3

Energy cost of digesting and distributing food
Accounts for 8% of TEE
Protein>carb>fat

Question 4

What makes up energy expended in physical activity (EEPA) and what fraction of TEE does it make?

Answer 4

EEPA = Non-exercise activity thermogenesis and physical activity
EEPA is variable but up to 30-40%

Question 5

TEE = ?

Answer 5

TEE = RMR + TEF + EEPA

Question 6

Average daily TEE = ?

Answer 6

25-35 kcal/kg/day (30)

Question 7

kcal/g for diet sources?

Energy pool?

Answer 7

EtOH = 7 kcal/g (no pool)
Protein (no pool) and glucose (glycogen) = 4 kcal/g
Fat = 9 kcal/g (large storage pool)

Question 8

Liver metabolism in fed state

Answer 8

Glucose uptake
G6P conversion to glycogen
Acetyl CoA via PDH which favors FFA and TCA
HMP Shunt

Question 9

Muscle metabolism in fed state

Answer 9

GLUT4/hexokinase
G6P to glycogen
AA uptake and protein synth
Minimal diet fat uptake (low LPL activity)

Question 10

Brain metabolism in fed state

Answer 10

Most of brain not insulin sensitive (GLUT1 and 3)

Aerobic metabolism of glucose

Question 11

Adipose metabolism in fed state

Answer 11

HSL is not active
De novo lipogenesis via glucose to FA to TG
Increased LPL action and chylomicron TG uptake

Question 12

Liver metabolism in fasting state

Answer 12

Glycogen degradtation
Gluconeogenesis
Glucose release into blood

Question 13

Muscle metabolism in fasting state

Answer 13

Gluconeogenesis via muscle protein (AA transported to liver)
Some glycogen breakdown
FFA main source for energy during fasting (increased LPL activity)
Lactate via Cori

Question 14

Brain metabolism in fasting state

Answer 14

Brain is obligate glucose user. Hepatic glycogenolysis and gluconeogenesis maintain concentrations

Question 15

Liver metabolism in starvation state

Answer 15

Gluconeogenesis from muscle protein, glycerol (low level)
Fatty acid oxidation occurs at high levels
Ketone body formation

Question 16

Muscle metabolism in starvation state

Answer 16

Catabolism releasing protein

FFA dependence for energy sparing ketone bodies for brain

Question 17

Brain metabolism in starvation state

Answer 17

Ketone body use necessary with decreasing BG

Also spares BG for RBC use

Question 18

Review glucose tests and levels for dx

Answer 18

Fasting glucose: <100, 100-125, >126
OGTT: <140, 140-199, >200
HbA1C: <5.7%, 5.7-6.4%, >6.5%

Question 19

Impaired glucose tolerance/pre-diabetes risk

Answer 19

Increased risk for macrovascular disease but not microvascular disease

Question 20

Symptoms of diabetes

Answer 20

1. Polyuria
2. Polydipsia
3. Blurry vision (lens swelling)
4. Weight loss

Question 21

Gestational diabetes

Answer 21

Pregnancy, hormone changes, and weight gain all predispose to insulin resistance
Increased risk for T2DM in the future (mom and kid)
Goal of tx is to prevent hyperglycemia in kid

Question 22

Features of hyperinsulinism in newborn

Answer 22

Large for gestational age
Glucose infusion to support normoglycemia
Large (>40) changes in BG after glucagon (suggests increased glycogen from increased insulin)

Question 23

Pancreatic diabetes

Answer 23

Caused by removal/injury or pancreatitis

Often accompanied by symptoms of etiology

Question 24

Estimate of energy expendature

Answer 24

EE (per day) = 25-35 kcal * kg

Question 25

Polyols

Answer 25

Sugar alcohols - reduced sugar, can't absorb, gas and fermentation Glucose -> glucitol (sorbitol)

Question 26

Glycemic index

Answer 26

For same 100g (amount of carbs), differences in glucose excursion Low GI = less BG spike over time High GI = more BG spike over time

Question 27

Low glycemic index examples

Answer 27

sourdough bread, apple juice, pumpernickel, oatmeal, pasta, Indian basmati rice

Question 28

Intermediate glycemic index examples

Answer 28

croissant, Coca-cola, raisin bran, whole grain bread

Question 29

High glycemic index examples

Answer 29

white bread, corn flakes, doughnut, white rice

Question 30

Glycemic load = ?

Answer 30

Glycemic index x amount of food | Increased GL = increased risk of adverse health outcomes

Question 31

Fructose metabolism enters glycolysis where? | What kind of adverse health outcomes?

Answer 31

After PFK-1, downstream in the 3 carbon section Therefore more readily cleared by liver and converted to pyruvate Adverse health outcomes: increased insulin resistance and hypertriglyceridemia

Question 32

Different ways to research diet and health (and what is the gold standard)

Answer 32

Animal studies Epidemiological studies Small RCTs with surrogate marker Large RCTs with dz specific endpoints (Gold standard)

Question 33

Starches

Answer 33

Amylopectin: highly branched, rapid absorption Amylose: long, unbranched, slow absorption (gas) Resistant corn starch: slowly absorbed, role in therapy for congenital illness

Question 34

Fiber

Answer 34

Soluble: Bulk forming, lower LDL, lower prandial glucose spike Insoluble: no water absorption

Question 35

Functions of Fatty acids

Answer 35

1. membranes 2. energy storage 3. hormone precursers