W2 - More Readings

Question 1

Antioxidants

Answer 1

Compound that can donate electrons to oxidised compounds = puts them in a more reduced (stable) state.

Question 2

What do oxidised compounds tend to be?

Answer 2

Highly reactive

Question 3

Give an example of a dietary antioxidant

Answer 3

Vitamin E

Question 4

What type of vitamin are niacin and riboflavin

Answer 4

B-vitamins

Question 5

What do niacin + riboflavin do?

Answer 5

Assist dehydrogenase enzymes by transferring H atoms from energy-yielding compounds to O2 in metabolic pathways.

Question 6

What is niacin when it functions as a coenzyme?

Answer 6

NAD (oxidised form)

NADH (reduced form)

Question 7

What is the result of NAD+ being oxidised

Answer 7

NAD+ –> NADH + H+

Question 8

What is riboflavin when it functions as a coenzyme?

Answer 8

FAD (oxidised form)

FADH2 (reduced form)

Question 9

Define energy expenditure

Answer 9

EE (kJ or kcal) per unit of time to produce power

Question 10

What is the imperial system of expressing energy?

Answer 10

Calories

Question 11

What is the metric system of expressing energy?

Answer 11

Joules

Question 12

Define gross efficiency

Answer 12

Ratio of total work to energy expended

Question 13

Define delta efficiency

Answer 13

Change in EE per min rel. to the change in actual work accomplished per min

Question 14

What does the energy content of CHO depend on?

Answer 14

Its type

Arrangement of atoms in it

Question 15

Define coefficient of digestibility

Answer 15

% of food energy that’s absorbed

Question 16

Define work efficiency

Answer 16

Baseline of the energy cost of unloaded work

Question 17

Methods to measure human energy expenditure

Answer 17

Direct + indirect calorimetry

Closed-circuit + open-circuit spirometry

Douglas bag technique

Breath-by-breath technique

Portable spirometry

Doubly labeled water

Labeled bicarbonate

HR monitoring

Accelerometry

Observations, records of PA

Question 18

Why was the direct calorimeter suit made?

Answer 18

To overcome some of the practical problems from the direct calorimeter chamber

Question 19

What does the direct calorimeter suit consist of?

Answer 19

Long plastic tube through which a known amount of H20 flows.

Tube touches skin to absorb body heat.

Question 20

Problems with the direct calorimeter suit

Answer 20

May impair movement

Question 21

What can be used to measure O2 uptake + CO2 production

Answer 21

Closed-circuit spirometry

Open-circuit spirometry

Question 22

What is the Closed-circuit spirometry used for?

Answer 22

To measure resting EE

Question 23

How does Closed-circuit spirometry work?

Answer 23

Spirometer prefilled w/ 100% O2

Subject breathes through mouthpiece into spirometer

W/ each inspiration some O2 is consumed.

Expired gas is passed back to spirometer, CO2 trapped in filter.

Residual O2 in chamber is avail. for next inspiration.

O2 in spirometer ⬇️

Change in vol. is measured

O2 uptake + EE is calculated.

Question 24

When is Closed-circuit spirometry useful?

Answer 24

In resting cond.

Not during exercise

Question 25

What does breath-by-breath systems allow?

Answer 25

Observe time course of changes in various ventilatory variables.

Question 26

Positives for breath-by-breath systems

Answer 26

Analyse every breath

Able to register rapid changes

Gives instant fb

Question 27

When is doubly labeled water only suitable for?

Answer 27

LT (days/weeks) estimation of EE

Question 28

Labelled bicarbonate

Answer 28

Infusion of labelled bicarbonate at a constant rate.

Reaches equilibrium w/ bodys CO2 pool.

After, any change in bodys CO2 prod will result in change in % of labelled CO2.

Question 29

Equation for EE (kcal) using an accelerometer

Answer 29

Distance covered (km) x body mass (kg)

Question 30

Equation for EE (kJ) using an accelerometer

Answer 30

Distance covered (km) x body mass (kg) x 4.184