Nutrition Flashcards
What are catabolic processes
Break down of molecules to release energy in the form of reducing power
What are anabolic processes
Using energy and raw materials to make larger molecules for growth and repair
What is the definition of energy
The capacity to do work
What 5 things do living things require energy for
Biosynthetic work, transport, mechanical work, electrical work and osmotic work
What type of energy do cells use to drive their energy requiring activities
Chemical bond energy
What are the units for food energy
Kilojoules
How many kilojoules are in a kcal
4.2
How many carbons does glucose have
6
What are monosaccharides
Carbohydrates made up of a single sugar unit
What are oligosaccharides
Carbohydrates made up of 3-12 sugar units
What is sucrose made up of
Glucose and fructose
What is lactose made up of
Galactose and glucose
What is starch made up of
Polymer of glucose
What is glycogen made up of
Polymer of glucose
How many essential amino acids are there
9
Why are some amino acids essential
They can’t be synthesised and so must be obtained from the diet
What are the 9 essential amino acids
Isoleucine, Lysine, Threonine, histidine, leucine, methionine, phenylalanine, tryptophan, valine
What are lipids made up of
Triacylglycerols (3 fatty acids linked to one glycerol)
Deficiencies in B12 and folate result in what
Anaemia
What is the daily energy expenditure the sum of
Basal metabolic rate, diet- induced thermogenesis and physical activity level
What is the basal metabolic rate
Energy used to maintain resting activities of the body
Which part of the body uses the most energy from the basal metabolic rate
Skeletal muscle (30%)
What factors affect basal metabolic rate
Body size, gender, temperature
what is metabolism
the chemical processes that occur within a living organism in order to maintain life
what 4 pathways are involved in metabolism
oxidative, detoxification, biosynthetic and storage
which bond is broken in ATP to release energy
the last phosphodiester bond between the gamma and beta phosphate groups
when are proteins used as a source of energy
in starvation
what 7 components make up our diet
carbohydrates, proteins, fat, minerals, vitamins, water and fibre
what is the carbohydrate store in humans
glycogen
which type of people may have more than 9 essential amino acids?
children and pregnant women as these extra amino acids are needed for rapid growth
true or false: proteins of a plant origin are of high quality
false - most plants don’t have all the essential amino acids unlike protein from animal origin
what are the 3 types of fat
saturated, unsaturated and trans
why are trans fat used in food production
they increase shelf life of food
why do fats yield the most energy when oxidised
they have less oxygen so give more energy when oxidised
what are the 2 essential fatty acids
linoleic and linolenic acids
what are the fat soluble vitamins
A, D, E, K
what are the minerals calcium and phosphate essential for
structure (bone and teeth)
which minerals are cofactors for enzymes
iron, magnesium, manganese, cobalt, copper and zinc
despite cellulose and starch both being glucose polymers, why cant they both be broken down in digestion
cellulose contains beta,1-4 linkages which we don’t have the enzymes to break down unlike the alpha,1-4 bonds in starch
how does fibre reduce cholesterol levels
fibres prevent bile salt being reabsorbed so that they form part of the faeces. Cholesterol is used to make bile salts so is lost with the bile salts
what is fibre essential for
normal functioning of the GI tract
what is the recommended intake of fibre
18g/day
what is the Reference Nutrient Intake (RNI)
the estimate of the amount of protein, vitamins and minerals needed by 97.5% of the population
what is the estimated average requirement (EAR)
the estimated amount of energy needed.
Approximately 50% of the population will require more than this and the other 50% will require less
what are dietary reference values
estimates about the amount of nutrients and energy needed by different groups
what is the Lower Reference Nutrient Intake
The amount of a nutrient or energy which is sufficient for only a few individuals (2.5%) the rest of the population will need more
what is safe intake
this is used when there is insufficient data . it is the intake at which there is no risk of deficiency
what is diet induced thermogenesis
energy required to process food
which type of tissue allows for long term store of energy
adipose
what is obesity
excessive fat accumulation in adipose tissue which impairs health. Having a BMI over 30
what diseases are associated with obesity
cardiovascular disease, cancers and type 2 diabetes
how do you calculate BMI
weight (KG)/ height squared (m)
what is the range for a normal BMI
18.5-24.9
what is the weakness of using BMI values
muscular individuals may be classed as overweight
how does a low protein intake lead to oedema
the liver produces less albumin, reducing the blood oncotic pressure. This means that less fluid moves back into the capillaries in the venous end
what is the normal level of glucose in the blood
3.3-6 mmol/L
What is marasmus
Deficiency in all nutrients so you have inadequate energy intake
What is kwashiorkor
Protein deficiency but adequate energy intake
What happens to the liver of children with kwashiorkor
Contains significant amounts of fats (fatty liver) as there’s no proteins to make enzymes and transporters to move fats out or metabolise them so they build up
Why do children with kwashiorkor have very low albumin concentrations
They don’t have the protein intake to produce albumin as they have no amino acids
Why do people with kwashiorkor have oedema
There’s less serum albumin so have a lower oncotic pressure in their capillaries
Why should you only give very small amount of food to start with to people with marasmus and kwashiorkor
They have a decreased regulation of enzymes so increasing protein means they get a build up of ammonia
