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Revision – Part 2
1. Fill in the 10 un-shaded boxes
(5 mark)
Nutrient
One function in the body – One
of the following answers
Vitamin C
Resist infection, promote
healing, maintain healthy skin,
gums, teeth, blood vessels,
promotes absorption of iron and
calcium, metabolise proteins
and manufacture hormones,
support folic acid and vitamin E
in their functions
Vitamin B3
Niacin
Metabolise proteins,
carbohydrates, fats, healthy
skin, maintenance of both the
digestive and nervous systems
Folate
Metabolism of proteins,
Formation of DNA and RNA
within cells,
Phosphorus
Found in bones and teeth.
One food it can
be found in, One
of the
following
answers
citrus fruits
potatoes
leafy greens
tomatoes
One excess/deficiency it can cause as
indicated
One of the following answers
Whole grain
cereals, red
meat, poultry,
seafood, nuts
and legumes
Deficiency
Disturbance of digestive and nervous
systems, pellagra
Whole grain
cereals, leafy
greens, milk,
peanuts,
avocadoes, yeast
and yeast
extracts, organ
meats
Deficiency
Anaemia during pregnancy, sterility in
males and females, neurological
diseases – ie Spina Bifita
Large blood cells are produced with
low folate levels and this affects white
blood cell and platelet numbers –
which affects blood clotting.
Can affect lining of the gut and
therefore hamper transfer of nutrients
from the gut to the bloodstream
Deficiency
Lean meat,
poultry, fish,
eggs, bran,
cheese, milk
Deficiency
Scurvy
Body cannot absorb correct amounts
of calcium
2. List the two types of fibre, explain their function within the body and state a food that contains this type of
fibre (6 marks)
(i)
Type Soluble Fibre
Function



attracts water and turns to gel during digestion
may help lower cholesterol
Allows nutrients to be released more slowly
Food Sources: oat bran, barley, nuts, seeds, beans, lentils, peas, Green leafy Veg
(ii)
Type Insoluble Fibre
Function



adds bulk to the stool
appears to help food pass more quickly through the stomach and intestines
Feeling of satiety
Food wheat bran, vegetables, and whole grains , Wholegrain bread, Skin of fruit and veg
3. Complete the table below
Basic building block
List type and food source
List two functions in the
body
1a Monosaccharide
1.
Carbohydrate
1. Glucose
2. Galactose
3. Fructose
2. b) Example
Glucose
Galactose
Fructose
1. To provide energy
2. To stimulate the digestive
system
3. To regulate the use of
protein by the body
c) Food source
Glucose (honey, grapes, ripe
fruits)
Galactose (dairy)
Fructose (fruit)
3. 2a. Disaccharide
4.
b) Example
Sucrose Lactose
Maltose
c) Food source
Sucrose – fruit and Veg
Lactose - Dairy
Maltose - beverages, beer, cereal,
pasta, potatoes and in many
processed products which have
been sweetened.
5. 3a Polysaccahride
b) Example
Starch
Soluble Fibre Insolube Fibre
Food source
Starch – Pasta, Rice, Corn
Soluble Fibre - oat bran, barley,
nuts, seeds, beans, lentils, peas,
green leafy veg
Insolube Fibre – wheat bran,
vegetables, and whole grains,
wholegrain bread, apple skin,
Protein
1.
Amino Acids
1. Complete protein food source
Any animal product OR soy
products
1. To build, maintain and repair
muscle tissue
2. To build antibodies
2. Incomplete protein food source
Plant based sources
3. To activate the growth
hormone
4. Create proteins (hemoglobin)
and enzymes
4. Explain why the villi are so effective at transferring nutrients from the digestive tract to the blood
stream?
(2 marks)
The villi increase the surface area of the digestive tract, thus providing a greater area over
which the uptake of nutrients can occur. The walls of the vili are very thin so absorption of
glucose, amino acids, water soluble vitamins and minerals can occur
5. Calculate the BMI of a woman aged 24 who weighs 72kg and is 180cm tall. Show all working out.
4.
An sedentary adolescent female has the following daily energy intake:



200 g carbohydrate – 200g X 16kj = 3,200kj
80 g protein 80g X 17kj = 1,360kj
100 g fat 100g X 37kj = 3,700kj
a) Calculate, as percentages, the energy distribution of the total carbohydrates, protein, and fats in the
adolescent’s energy intake. The total energy intake is 8260kJ
(Show all calculations and answers to the nearest whole number).
(3 marks)
(i)
Carbohydrates
3,200kj / 8260 = 39%
(ii)
Protein
1,360kj / 8260 = 16%
(iii) Fats
3, 700kj / 8260 = 45%
5. David is a 40-year old man who weighs 84 kilograms. His daily energy intake is 12500 kilojoules. His daily
energy expenditure is made up of the following activities:


30 minutes of jogging = 1115kJ
1 hours of very light activity (dressing, reading) = 500 kJ
The thermogenic effect of food accounts for 10% of his total daily kilojoule intake:
a)
Calculate his basal metabolic rate, showing calculations
84 x 1.0 x 24hrs x 4.2 = 8,467.2kj
b) (1 mark)
b) Calculate thermic effect of food
The thermic effect of food is the energy used in digestion, absorption, metabolism
and the storage of ingested nutrients.
Thermic effect of food is estimated at 10% of energy intake =10 / 100 x 12500 =
1250kj
c) Calculate his total daily energy expenditure
BMR 8,467 kj + 1250 kj (10% thermic effect) + exercise 1,615 kj = 11,332 daily
energy expenditure
Energy intake =
12,500
Minus expenditure
-11332
= 1168kj
d) Positive balance will gain weight at this continued pattern
6.
a) On the following diagram, make annotations to show how/where a buttered roll is digested.
(The buttered roll is mostly carbohydrate and fat, almost no protein)
(3 marks)
Mouth
Mechanical Physical – salivary amylase
breaks down starch in bread
roll Maltose
Liver
Stomach
Produces bile for
emulsification of
fats
Food combines with
gastric juices to
produce chime.
Gastric juices contain
HCL, this uncoils
proteins and allows
enzyme pepsin to
break
proteins– into
Pancreas
send
peptones.
pancreatic enzymes
to duodenum and
completes breakdown
of F,C & P
Gall Bladder
Stores Bile
Duodenum
Lipases break down
fat once it has been
emulsified by bile
Large intestine – break down of soluble fibres
by bacteria and products absorbed
b) What role does the gall bladder play in the digestion of fat?
(1 mark)
Stores and releases bile into digestive system. The bile emulsifies fats into smaller droplet to
increase surface area for more efficient enzyme breakdown by lipases.
c) Complete the table below.
Location in the digestive system
An enzyme involved in digestion at this site
Mouth
Amylase (carbohydrate)
Stomach
Peptases / pepsin
Small intestine
a) Fat - lipase
b) Carbohydrate - maltase, sucrase, lactase, pancreatic
amylase
c) Protein - proteases
C) Describe the digestion of lipids in the small intestine (2 marks).
Bile released from the liver emulsifies fat into smaller globules. The enzyme lipase, which is excreted from
the pancreas, then converts fats into fatty acids and glycerol.
7. Describe the role of mechanical digestion of protein in the stomach ( 2marks).
The muscle lining the stomach churns the food, which mixes with the gastric juices to produce chime.
8. Describe the chemical digestion of protein in the stomach (2 marks).
The enzyme pepsin starts the breakdown of proteins into smaller chains of amino acids.
9. Complete the table below. (6 marks)
Macronutrient
Site of Digestion
One Enzyme Involved
in Digestion
End Product of
Digestion
Protein
Stomach
Pepsin, HCL
Amino Acids
Lipids
Small Intestine
Lipase
Glycerol & Fatty Acids
Carbohydrate
Small Intestine
Amylase
Glucose
7a) Describe the difference between haem and non haem iron.
(2 marks)
Haem iron is readily absorbed by the body and meat and fish supply haem iron.
Non haem iron is not as readily absorbed and is found in plant sources.
b) Name a micronutrient that can help increase the absorption of the iron contained in spinach.
Vitamin C
(1 mark)
c) Name a food that inhibits the absorption of iron.
(1 mark)
Fibre if large amounts of unprocessed bran is consumed and coffee
d) Give two reasons why we need to consume iron.
(2 marks)
Formation of red blood cells in the protein haemoglobin and forms part of myoglobin in
muscles (makes oxygen available for muscle contraction)