22

Question 1

‘ First Law of Thermodynamics

Answer 1

The total energy within a system is constant

Energy can neither be created or destroyed
Energy can be converted
Biology relies on energy conversions

Question 2

Energy can neither be _____ or _______
Energy can be _______

Answer 2

Created
Destroyed
Converted

Question 3

Biology relies on

Answer 3

Energy Conversions

Question 4

Energy balances in cells and organisms

Answer 4

Question 5

Answer 5

Hybrid

Question 6

Food consist is of

Answer 6

Chemical energy:
- carbohydrates
- fats
- proteins

Nutrients:
- vitamins, minerals, etc

Question 7

Individuals diets…

Answer 7

…vary

Question 8

Through digesition we have the realise of …

Answer 8

…carbon components as carbon dioxide

Question 9

Digestion of food components down into smaller units such as:

Answer 9

• glucose
• fatty acids
• proteins
• vitamins and minerals

(Makes them easier to absorb and is then circulated to different tissues)

• this process generates a certain amount of heat

Question 10

After molecules are digested into the smaller components:

Answer 10

• large range of metabolic processes
  Metabolism:
• glycolysis
• B-oxidation (lipids - manages their resources, whether they are stored or taken up in diet)
• citric acid cycle
  ATP - cellular work

Storage
- TAGS
- glyciogen

Evolved to intercorperate compounds into forms that are important for varieties celluluar functions and release some of the potential energy and get it into the form of ATP - makes energy available for cellular work

Question 11

Answer 11

Question 12

Carbon compounds in food are oxidised to form

Answer 12

ATP

Question 13

What compounds in food car oxidised to form ATP?

Answer 13

Carbon compounds

Question 14

Energy balcances in the body - Eintake = Eexpended + Estored

Answer 14

E stored in principlely lipid = weight gain

Question 15

Obesity amount adults - stored energy

Answer 15

Question 16

Weight loss can be achieved by:

Answer 16

• reduced energy intake (eat less and/or take certain drugs)
• increasing activities
• increasing basal metabolism

Question 17

What is basal metabolism

Answer 17

The energy required for maintenance of life

Question 18

What is leptin?

Answer 18

The peptide leptin is made in the fat cells, circulates in blood and signals to brain that enough energy is stored in the body, hence controls ‘hunger’

Question 19

Joule (J) =

Answer 19

energy required to push against 1 Newton of force for 1 metre

Question 20

1 cal =

Answer 20

4.184 J

Question 21

1 Cal (kilocalorie) - capital C =

Answer 21

4.184 kJ

Question 22

Daily dietary energy intakes and energy expenditure usually measured as

Answer 22

MJ ie 1000 kJ

Question 23

The energy content of foods can be measured by

Answer 23

The energy content of foods can be measured by calorimetry

Question 24

Atwater factors

Answer 24

Fat = 38 kJ/g
Carbohydrate = 17 kJ/g
Protein = 17 kJ/g
Ethanol = 29 kJ/g

(- under experimental conditions purified material is completely combusted - then able to measure the energy released from doing that combustion process - how to measure Atwater factors (typical energy value))

Question 25

Why not all the energy in food is available

Answer 25

Losses in faeces ie fibre (cellulose B-glycosidic linkage can’t be hydrolysed )
Nitrogen is not oxidised (excreted in urine)
Have to adjust for these factors

Question 26

Not all energy from food is available

Answer 26

Yeah

Question 27

Yap

Answer 27

• range of energy across materials
• people consuming higher levels of high energy compounds- there is a bigger energy input that has to be balanced against energy required for activities and storage

Question 28

Measuring energy expenditure: direct calorimetry - whole body calorimeters - what does it rely on measuring? What’s it good for determining?

Answer 28

Question 29

Indirect calorimetry - what is it based on? How does it work? How much head is produced per mole of O2?

Answer 29

• based on O2 consumption and CO2 production measured using a respirometer
• a certain amount of energy is associated with every litre if O2 consumed
• Heat produced per mole of O2 = 2813/6 = 469 kJ/mol
• As 1 mol of O2 at STP = 22.4L
  469 kJ / 22.4L = 20.9 kJ/L

(STP = standard temperature and pressure)

Question 30

What are the two things an indirect calorimetry allows for?

Answer 30

• allows for calculation of energy expenditure for a wide range of activities
• also allows calculation of the ‘respiration exchange ratio’ (RER)

Question 31

‘respiration exchange ratio’ (RER)

Answer 31

• calculation of energy expenditure for a specific individual in a specific energy state

Question 32

The more robust the energy…

Answer 32

… the more energy consumed

Question 33

RER can determine fuel is being used

Answer 33

(What is the flex between carbohydrate and lipid material in the body)

Question 34

B asal metabolism

Answer 34

Energy required for maintenance of life:
Muscle contractions
Nerve conduction
Ion transport
Synthesis of macromolecules
Maintenance of body heat

Usually defined as energy expenditure at rest - changes depending on individuals

‘Basal metabolic rate’

Question 35

Factors affecting basal metabolism include:

Answer 35

gender, age, body size and composition, genetics, hormonal status, stress levels, disease status, certain drugs

Question 36

Basal metabolism, increased by

Answer 36

Athletic training Late stage of pregnancy Fever Drugs eg caffeine Hyperthyroidism

Question 37

Basal metabolism, decrease by:

Answer 37

• malnutrition
• sleep
• drugs ie B-blockers
• hypothyroidism

Question 38

Respirometers

Answer 38