Metabolism Session 1 - Introduction and Energy Reactions in cells Flashcards Preview

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Flashcards in Metabolism Session 1 - Introduction and Energy Reactions in cells Deck (57):
1

Define and give approximate value of your daily energy expenditure
Adult male weight and daily energy?
Adult female weight and daily energy?

12,000 KJ - 70kg
9500 KJ - 58kg

2

Define and give approximate value of your daily energy expenditure
Three parts of daily energy expenditure

1) Energy to support BMR
2) Energy for voluntary physical activities
3) Energy required to process the food we (diet induced thermogenesis)

3

Define and give approximate value of your daily energy expenditure
Define BMR

A measure of the basal energy required to maintain life - the function of various tissues of the body at physical, emotional and digestive rest.

4

Define and give approximate value of your daily energy expenditure
Major tissues contributing to BMR and values

Skeletal muscle - 30%
CNS - 20%
Liver - 20%
Heart 10%

5

Define and give approximate value of your daily energy expenditure
How is BMR calculated and what are the units?

What group of people can you NOT use this calculation for?

BMR = weight in kg x100
kJ/24hr
Obese people

6

Define and give approximate value of your daily energy expenditure
How does change in temperature effect BMR?
What two other factors effect BMR?

10% for ever 1* increase in body temp

Excessive secretion of thyroid hormone, pregnancy and lactation

7

What calculation is used to determine VPA energy of a person who engages in 2hr of moderate exercise per day

BMR + 60-70% of BMR

8

Why is energy needed for diet induced thermogenesis?
What is the energy required to process food equal to?

To digest, absorb, distribute and store nutrients

10% of the energy content of ingested food

9

What is the RDA?

The quantities of nutrients required to keep the general population in good health

10

What are the seven necessary factors in diet?

Fat, Carbohydrate, Protein, Vitamins, minerals, water and fibre

11

How is a reaction described when energy released in greater than energy input?

Exergonic

12

Give energy values for fat, carbohydrate, alcohol and protein

37 kJ/g, 17kJ/g, 29 kJ/g and 17kJ/g respectively

13

Why is there no absolute requirement for glucose in the diet?

Can be obtained via gluconeogenesis

14

What are the three uses of fats in the body?

- energy yield 2.2x greater than carbohydrate, so do not have to eat as much
- Vital for absorption of fat soluble vitamins ADEK
- Certain polynsaturated fatty acids (essential) such a linoleic and linolenic acids form structural components of cell membrane and precursors of important regulatory molecules (eicosanoids)

15

What is the turnover of tissue protein in an adult male/day?

400g/day

16

How much protein is lost per day be an adult male and thus how much is required in diet?

35g/day

17

Why does the body need dietary protein?

To supply essential amino acids which are not synthesised by the body, such as lysine

18

How much water is lost from the body each day?

2.5 litres

19

What percentage of an adults body mass is water?

50-60%

20

What is dietary fibre necessary for?

Normal bowel function

21

Why are mineral and vitamins essential? (two reasons)

Prevent defiency
Some have important anti-oxidant properties

22

How do you calculate BMI?

weight (kg)/height^2(m)

23

What is an obese BMI?

30-34.9

24

What is a desirable range of BMI?

18.5-24.9

25

What is a valid alternative to measuring BMI?

Waist to hip ratio

26

Define obesity

A chronic conditoon characterised by excess body fat and often determined on the basis of BMI

27

What 5 diseases is obesity associated with?

Hypertension, heart disease, stroke, type 2 diabetes, gall bladder disease and osteoathritis

28

Why is total starvation not a preferred method of weight loss? (2)

Protein metabolism increases to maintain blood glucose via gluconeogenesis, so lean body mass quickly begins to disappear. Liver begins to convert fatty acids to ketones, which disturbs blood pH and can lead to dehydration

29

Name three factors which complicate treatment of malnourished patients.

Longer hospital admission, respond less wlel to treatment, three times more like to develop complications after surgery and have a higher mortality rate

30

What are the causes of malnutrition? (4)

Under nutrition (anorexia nervosa, bulimia nervosa)
Protein energy malnutrition
Over nutrition
Malabsorption conditions (chrohn's disease)

31

Give 9 symptoms of marasmus

Cold
Weakness
Infections of lung and GI tract
emaciated
Muscle wasting
Loss of body fat
DAD (thin dry hair, anaemia, diarrhoea)

32

Give symptoms of kwashiokor, and what causes it?

Occurs in young children displaced from breafeeding by a new baby and fed a diet with some carbohydrate, but low protein content
ALA (apathetic, lethargic, anorexic)
Generalised oedema
Hepatomegaly and ascites (cause distended abdomen)
Anaemia

33

Define homeostasis

The control of the internal environment within set limits and via a dynamic equilibrium, which occurs and cellular, organ system and whole body level

34

Give three examples of what homeostasis controls

Supply of nutrients, oxygen and blood flow

35

What does the failure of homeostasis lead to?

Disease

36

Where do cell nutrients come from? (3)

Diet, synthesis in body tissue from precursors
Released from storage in body tissues

37

What happens to nutrients at body tissues? (5)

DIE SS
Degradation to release energy
Interconversion to other nutrients
Excretion - Liver, kidney and lungs
Synthesis of cell components
Storage - Liver, adipose tissue, skeletal muscle

38

What is cell metabolism?

Highly integrated network of chemical reactions that occur within cells

39

What do cells metabolise nutrients to provide? (4)

Energy for cell function and the syntheisis of cell components
Building block molecules that are used in synthesis of cell components
Organic precursor molecules that are used to allow the inter-conversion of building block molecules (acetyl-COA)
Biosynthetic reducting power used in synthesis of cell components (NADPH)

40

What are catabolic pathways? (4)

-Oxidative
-Large to small molecules
-Release large amounts of free energy
-Produce intermediary metabolites

41

What are anabolic pathways? (5)

-Reductive
-Small to large molecules
-use energy produced from catabolism
-Use intermediates
-Drive synthesis of important cell components

42

What is oxidation?

Removale of electron or H-atoms (H+ and e-) from fuel molecules

43

In the body, what are H-atoms transferred to?

Carrier molecules, such as NAD, NADP and FAD

44

What are the dietary vitamins which are needed for NAD and FAD

Niacin and Riboflavin

45

What reactions oxidise carrier molecules such as NADH and FAD2H?

Cell respiration - Oxidised in a series of reactions, and ultimately reduce oxygen to water
Reactions in which substrate is reduced (anaerobic respiration) (Use NADH or FAD2H)
Biosynthetic reactions involving reduction steps (use NADPH) Fatty acid and cholesterol synthesis

46

When energy is relased, what is the enthalpy change and what type of reaction is it?

Negative, exergonic

47

What is the free energy change equation?

Change in G = Change in H - Txchange in S

48

What is the role of ATP in the body?

Serves as intermediate energy store
Energy released in exergonic reaction

49

When are catabolic pathways activated?

When there are lots of low energy singlals, such as ADP, AMP or NAD+

50

When are anabolic pathways activated?

When there are lots of high energy signals such as ATP and NADH

51

What is creatine phosphate, and how is its production activated?

A molecule which acts as a small store of energy in muscle cells, and produced when levels of ATP are high

52

What is creatinine clinically relevant?

Because the rate of production of creatinine is proprtional to the concentrate of creatine in muscles, which is related to skeletal muscle mass. Increased creatinine secretion could be indicative of muscle wasting.

53

What can ,measurements of concentration of creatinine in urine and blood serve as indicator of?

Kidney function. A high ratio of blood to urine creatinine could indicate reduced kidney function.

54

What is the equation for Creatine Phosphate production, and what enzyme catalyses it?

Creatine + ATP --> Creatine Phosphate + ADP
Creatine kinase

55

Give three reduced carrier molecules

NADH + H+
NADPH + H+
FAD2H

56

Define Marasmus

Inadequate calorie intake and inadequate protein intake
-- protein-energy malnutrition

57

Define Kwasiorkor

Adequate calorie intake, inadequate protein intake