Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Metabolism - Semester 1 > Week 1- Nutrition, body weight and homeostasis > Flashcards

Week 1- Nutrition, body weight and homeostasis Flashcards

1
Q

Energy

A

Capacity to do work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do living cells require energy for?

A
  1. Biosynthetic work - synthesis of cellular components
  2. Transport work across cell membranes - maintenance of ion gradients, uptake of nutrients
  3. Muscle contraction
  4. Nervous conduction
  5. Osmotic work - kidney
  6. Thermogenesis
  7. Detoxification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

SI unit of food energy

A

Kilojoule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

1 kilocalorie equals how many kilojoules?

A

1 kcal = 4.2 kilojoules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which type of energy is used to drive the energy-requiring activities of the cells in the human body?

A

Chemical bond energy: used directly without prior conversion to heat, as the human body is isothermal and under this condition heat energy cannot be used for work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Chemical bond energy

A

-Form of potential (stored) energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Exergonic

A

Energy released is greater than the energy input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Energy is produced by oxidation of which fuel molecules?

A
  1. Carbohydrates
  2. Proteins
  3. Fat
  4. Alcohol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Components of daily energy expenditure:

A
  1. Energy to support our basal metabolism - Basal metabolic rate
  2. Energy for voluntary physical activities
  3. Energy required to process the food we eat (diet-induced thermogenesis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Basal metabolic rate

A 
Measure of the basal energy required to maintain life - functioning of the various tissues of the body at physical, digestive and emotional rest
Major tissues contributing to BMR:
1. Skeletal muscle = 30%
2. Central nervous system = 20%
3. Liver = 20%
4. Heart = 10%

Rough estimate of BMR (kJ/24 hours): multiplying body weight in kg by 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Factors that affect basal metabolic rate:

A
  1. Controlled by thyroid hormones: excessive secretion (hyperthyroidism) increases BMR
  2. Gender: BMR is lower for women than for men of the same weight as women have more adipose tissue that is less metabolically active than lean tissue
  3. Temperature: BMR increases by 10% for every 1 degree celcius increase in body temperature
  4. Pregnancy and lactation increase BMR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Voluntary physical activity

A

-Energy required by skeletal and cardiac muscle
Rough estimate of total daily energy required for physical activity:
1. BMR + 30% of the BMR: sedentary person
2. BMR + 60-70% of the BMR for a person who engages in approximately 2 hours of moderate exercise a day
3. BMR + 100% of BMR for a person who does several hours of heavy exercise a day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Diet-induced thermogenesis:

A
  • Following the ingestion of our food, our metabolic rate increases because energy is required to digest, absorb, distribute and store nutrients.
  • Energy required to process the food is approximately equal to 10% of the energy content of the ingested food
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Macronutrients

A

Nutrients that are required in relatively large amounts

Examples: carbohydrates, fat, protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Recommended dietary allowance (RDA)

A
  • Quantities of nutrients required to keep the general population in good health
  • Considerably higher than the minimum amounts required to prevent deficiency symptoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Estimated average requirement

A

For energy or a nutrient is the amount that any stated group of people will on average need
-RDA and EAR: represents an average need over a number of days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Energy content of fat, carbohydrate, proteins and alcohol

A
  1. Fat: 37 kJ/g
  2. Carbohydrate: 17 kJ/g
  3. Protein: 17 kJ/g
  4. Alcohol: 29 kJ/g
18
Q

Which tissues need a constant supply of glucose as a source of energy?

A
  1. Brain

2. Red blood cells

19
Q

Alternate ways that body can produce glucose:

A
  1. Gluconeogenesis from certain amino acids
  2. Glycerol released from the hydrolysis of triacylglycerol
  3. Can be synthesised from dietary sugars such as galactose and fructose
20
Q

Importance of fats in the diet:

A
  1. Energy yield sometimes 2.2 times greater than carbohydrates or proteins
  2. Necessary for absorption of fat-soluble vitamins (A,D, E and K) from the gut
  3. Certain polyunsaturated fatty acids (the essential fatty acids) notably linoleic and linolenic acids, which are structural components of cell membranes and precursors of important regulatory molecules (eicosanoids)
21
Q

Why protein is required in the diet:

A
  1. Amino acids are used in the synthesis of a number of essential N- containing compounds including creatine, purines, pyridimines and haem (part of haemoglobin)
  2. To remain in zero nitrogen balance (nitrogen intake=nitrogen loss), an adult male has an average daily requirement of about 35 grams
  3. Growing children and women during pregnancy need more protein and normally show a positive nitrogen balance (nitrogen intake > loss)
  4. To supply essential amino acids which are not synthesised by the body
    Proteins of animal origin: contain a high proportion of the essential amino acids unlike proteins of vegetable origin
22
Q

Other dietary requirements/essential nutrients:

A
  1. Water:
    -Adult: 50-60% of body weight is water
    -Average water loss is approximately 2.5 litres per day
    -Ways water is lost: urine, expired air, through the skin, faeces
  2. Dietary fibre:
    Non-digestible plant material such as cellulose is necessary for normal bowel function
  3. Minerals and vitamins: some vitamins and minerals have important antioxidant properties in the body such as vitamin C, E and selenium
23
Q

Measures of health:

A
  1. Body mass index

2. Waist to hip ratio: better measure of obesity and the risk of cardiovascular disease

24
Q

Obesity

A

Chronic condition characterised by excess body fat

25
Q

Conditions that obesity can increase risk of:

A
  1. Hypertension
  2. Heart disease
  3. Stroke
  4. Type 2 diabetes
  5. Certain cancers
  6. Gall bladder disease
  7. Osteoarthritis
26
Q

Why distribution of fat within the body is clinically important:

A

Obese persons with a greater proportion of fat within the upper body, especially in the abdomen, compared with that on the hips have increased risk of:

  1. Insulin resistance
  2. Hyperinsulinism
  3. Type 2 diabetes
  4. Hypertension
  5. Hyperlipidaemia
  6. Stroke
  7. Premature death
27
Q

What are the metabolic changes during starvation?

A
  1. Protein metabolism increases to maintain blood glucose by gluconeogenesis: conversion of amino acids to glucose; lean body mass begins to disappear
  2. Liver begins to convert fatty acids to ketone bodies that can be used as a fuel by the CNS–> they can disturb blood pH and lead to dehydration
28
Q

Malnourished patients:

A
  1. Likely to have longer hospital admissions
  2. Respond less well to treatment
  3. 3 times more likely to develop complications after surgery
  4. Higher mortality rates
29
Q

Malnutrition

A
  1. Condition caused by an imbalance between what an individual eats and what that individual requires to maintain health
  2. Can result from over-nutrition or under-nutrition (eating disorders, reduced availability of food in many developing countries: protein-energy malnutrition)
  3. Malabsorption conditions: Crohn’s disease, Coeliac disease
    - Failure to digest and/or absorb ingested nutrients
30
Q

Marasmus

A
  • type of protein-energy malnutrition
  • Most commonly seen in children under the age of 5
  • Emaciated with obvious signs of muscle wasting and loss of body fat although there is no eodema
  • Hair: thin and dry
  • Diarrhoea is common
  • Anaemia may be present
31
Q

Kwashiorkor

A
  • Typically occurs in a young child displaced from breastfeeding by a new baby and fed a diet with some carbohydrate, but a very low protein content (e.g. cassava)
  • Child is apathetic, lethargic and anorexic (loss of appetite)
  • Generalised oedema
  • Distended abdomen: hepatomegaly (enlarged liver) and/or ascites (accumulation of fluid in peritoneal cavity)
  • Serum albumin is low
  • Anaemia is common
32
Q

Homeostasis

A
  • Control of the internal environment within set limits
  • Dynamic equilibrium
  • Homeostatic mechanisms are operating continuously to counteract changes in the internal environment
  • Failure of homeostasis –> disease
  • Examples of parameters under homeostatic control: supply of nutrients, supply of oxygen, blood flow, body temperature, removal of metabolites
  • In cells: the level of free calcium
  • In working skeletal muscle: local blood flow adjusted by autoregulation depending on metabolic demands
33
Q

Essential amino acids

A 
Isoleucine
Lysine
Threonine
Histidine
Leucine
Methionine
Phenylalanine
Tryptophan
Valine
34
Q

Conditionally essential amino acids

A

Small quantities of arginine can be synthesised in the body.

  • Only become necessary during periods of active growth such as pregnancy
  • Tyrosine can be synthesised in the body from phenylalanine: may become essential if diet is low in phenylalanine
  • Cysteine can be synthesised from methionine
35
Q

Name all fat-soluble vitamins.

A
  1. A (retinol)
  2. D (cholecalciferol)
  3. E (tocopherols)
  4. K (e.g. phylloquinone)
36
Q

Name all water-soluble vitamins.

A
  1. C (ascorbic acid)

2. B-complex: B1 (thiamin), B2 (riboflavin), B3 (niacin), B6 (pyridoxine), Folic acid, B12, Biotin, Pantothenic acid

37
Q

Major minerals

A

Ca, P, Mg, S, Na, K, Cl

38
Q

Trace elements

A

Fe, Zn, I, Se, Cu, Mn, F, Cr, Mo

39
Q

What happens to dietary fuel that exceeds the body’s immediate energy needs?

A
  1. Stored as fat in adipose tissue

2. Stored as glycogen in liver and muscle

40
Q

Metabolism

A

Chemical processes that occur within a living organism to maintain life

41
Q

Catabolic processes

A

Break down molecules to release energy in the form of reducing power

42
Q

Anabolic processes

A

Use energy and raw materials to make larger molecules for growth and maintenance

Metabolism - Semester 1 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions