Metabolism L1.1

Question 1

Describe metabolism

Answer 1

Chemical reactions which mainytain the living state of cells in our body

Reactions allow extraction of chemical energy from food to carry out diverse fucntions + biosynthesis of all molecules essential to maintain life

Whole body metabolism = Refers to mebaolic processes in organism

Cell metabolism = Refers to chemical reactions inc cells

Question 2

Describe the different pathways involved in metabolism

Answer 2

1. Degradative pathways: Convert food to energy
2. Biosynthetic pathways: Produce structural + functional cell components
3. Fuel storage + mobilisation pathways: Allow fuel to be stored + mobilised when we are not eating / need to increase energy
4. Detoxification pathways: remove toxins

Question 3

Define catabolism

Answer 3

Break down of larger molecules into samller molecules to release energy

Question 4

Define anabolism

Answer 4

Using energy (from catabolism) to synthesise larger molecules from smaller ones

Question 5

Diagram showing how energy is extracted from food

Answer 5

Question 6

State the two groups of nutrients

Answer 6

1. Macronutrients
2. Micronutrients

Question 7

State exampless of macronutrients

Answer 7

1. Carbs - energy
2. Proteins - energy + amino acids
3. Fats - energy + fatty acids

Question 8

State examples of micronutrients

Answer 8

1. Vitamins + minerals
2. Water - hydration, digestion, temp regulation
3. Dietry fibre (type of carb, does not provide energy) - necessary for normal function of GI tract

Question 9

9 essential amino acids (do not need to memorise at the moment)

Answer 9

Proteins of animal origin = high quality (becasue contain all essential amino acids)

Proetins of plant origin = low quality (deficient in 1/more essential amino acid) (thats why veg diet needs to have proteins from wide variety of sources)

Question 10

State the most common class of dietry fats

Answer 10

Triacylglycerols (TGs)

Question 11

Where are TGs stored in humans?

Answer 11

Adipose tissue

Question 12

What are the products of digestion of TGs

Answer 12

1. Fatty acids
2. Glycerol

Question 13

State uses of fatty acids in body

Answer 13

Most important: Omega 6 (linoleic) and omega 3 (a-linolenic), cannot be synthesised in body, need to come from diet. ESSENTIAL

1. Structural components of cell membranes
2. Precursors of eicosanoids (regulatory molecules)
3. Required for absorptuon of fat-soluble vitamins (A,D,E,K) from gut

Question 14

State risks of high fat intake

Answer 14

1. Weight gain
2. Insulin resistance
3. Non-alcoholic liver disease
4. Heart disease
5. Colorectal cancer

Question 15

Describe different types of fatty acids

Answer 15

1. Saturated (with C-C): Dairy, meat, veg, oils. High intake leads to cholestrol levels rising, risk of heart disease
2. Unsaturated (C=C cis): Plant=based, fish oils, nuts e.g. Oleic. Good for brain + heart
3. Unsaturated (C=C trans): Partially hydrogenated oils, readt-made cookies, deep fried foods e.g. elaidic. High intake leads to heart disease

Question 16

State the use of dietry fibre

Answer 16

Carb, not broken down by human digestive enzymes

1. Essential for optimal use of GI tract

Question 17

Describe types of dietry fibre

Answer 17

1. Soluble (oats, fruits, veg): pecrin + gums - help lowering cholestrol
2. Insuluble (whole grains, veg): lignin, cellulose. HUMANS DO NOT HAVE DIGESTIVE ENZYMES TO BREAK B-1,4 LINKAGES IN CELLULOSE. add bulk to stool, promoting bowel movements

Question 18

State risk factors of low fibre intake

Answer 18

Constipation + bowl cancer

Question 19

State risk factors of high fibre intake

Answer 19

Reduce cholestrol, risk of diabetes

Question 20

State recommended intake of dietry fibre for adults daily

Answer 20

30g

Question 21

Are Vitamins Fat / Water soluble?

Answer 21

Yes

Question 22

Fat soluble vitamins

Answer 22

DO NOT NEED TO MEMORISE

Xeropthalima - very dry eyes

Question 23

WATER SOLUBLE VITAMINS

Answer 23

Scurvy - saw, bleeding, gums

Question 24

State important minerals

Answer 24

1. Electrolytes (Establish ion gradients across membranes, maintain water balance)
2. Calcium + phosphorus (structure of bone + teeth)
3. Calcium (signalling)
4. Minerals are Enzyme co-factors (iron, magnesium, manganese, copper, zinc, molybdenum)
5. Iron - essential component of haemoglobin
6. Iodine - thyroid hormone synthesis

Question 25

Answer 25

Catabolic Carbs, proteins, fats ADEK

Question 26

What factors affect dietary reference values (DRVs)?

Answer 26

1. Age 2. Gender 3. Growth 4. Physical activity (asses intake of nutriantes to prevent deficiencies)

Question 27

State types of DRVs

Answer 27

Question 28

Describe daily energy expenditure

Answer 28

Total energy expended by individual in day. Sum of: 1. Basal metabolic rate (BMR) 2. Diet induced thermogenesis (DIT) 3. Physical activity level (PAL)

Question 29

Define basal metabolic rate

Answer 29

Energy required during physical, digestive, emotinal rest at 18 degrees celcius. Sum of all tissues in body MAINTAINS RESTING ACTIVITIES OF BODY - functions of cells - ion transport across membranes - biochemical reactions FUNCTIONS OF ORGANS BODY TEMP

Question 30

Describe energy utilisation in the body

Answer 30

Basal metabolic rateL energy used in physical, digestive + emotional rest at 19 degrees celcius. Sum of all tissues in body Physical activity (muscular work) Specific dynamic action of food: energy used in ingestion, digestion, absorption of heat Energy lost as heat

Question 31

State factors affecting BMR

Answer 31

Question 32

Describe the balance between energy and body weight

Answer 32

Question 33

State the formula for BMI

Answer 33

Body Mass Index

Question 34

Define BMI

Answer 34

Evaluates healthy weight in relation to height

Question 35

State two considerations when measuring BMI

Answer 35

(height measured without shoes, weight in minimal clothing)

Question 36

Describe the correlation between BMI and overall body fat

Answer 36

Positive correlation However, very muscular individuals wrongly classified as obese

Question 37

Define WHR (waist-to-hip-ratio)

Answer 37

Measures fat distrobution around abdomen + hips This is fat around central area Fat around central area = more metabolically active This can lead to hyperinsulinemia

Question 38

Describe the risks of a greater proportion of fat in upper body (abdomen) compared to hips

Answer 38

Question 39

Only Question 2

Answer 39

1. Energy lost as heat / diet induced thermogenesis 2. Physical activity (muscular work) 3. Specific dynamic action of food: energy used in ingestion, digestion, absorption of heat 4. Basal metabolic rateL energy used in physical, digestive + emotional rest at 19 degrees celcius. Sum of all tissues in body

Question 40

State causes and risk factors of obesity

Answer 40

Cause: excess energy intake, reduced physical activity, reduced sleep, genetics, medications, diseases Risk factors: Diabetes, cardiovascular diseases, cancers

Question 41

State causes and risk factors of malnutrition

Answer 41

Diet not providing righht amounts of nutrients / energy

Question 42

Describe causes and risk factors of Kwashiorkor

Answer 42

Cause: protein deprivation is greater than total energy intake (very low protein intake), they may be having energy from other sources, but so protein deprived Presents with Oedema (swelling), stunted growth, decreased fat, muscle mass, hepatomegaly (enlraged liver), anaemia

Question 43

Describe causes and risk factors of marasmus

Answer 43

Cause: Calorie deprivation greater than reduction in protein intake (INADEQUATE ENERGY IN ALL FORMS, protein and calories) Presents with stunded growth, extreme muscle wasting, loss of fat, anaemia DOES NOT PRESENT WITH OEDEMA

Question 44

How can we distinguish between kwashiorkor and marasmus

Answer 44

Marusmus does not present with oedema (as there is some protein in diet)

Question 45

Describe the use of MUST (Malnutrition Universal Screening Tool)

Answer 45

Evidenbce based tool used to screen malnutrition 5 steps. Identifies malnutrition in adults