Unit 3 AOS 1 (Chap 1-6) Flashcards
(96 cards)
1
Q
Appetite
A
the desire for food
2
Q
Chemical digestion
A
the breakdown of food using chemicals such as enzymes and acids
3
Q
Digestion
A
the process by which food is broken down into substances that can be absorbed and utilised by the body
4
Q
Enzymatic hydrolysis
A
a chemical digestive process that breaks down food by breaking the bonds that hold together the molecular ‘building blocks’ within the food
5
Q
Flavour
A
a combination of the taste and aroma of food
6
Q
Glycaemic index (GI)
A
a measure of how fast and how much a food raises blood glucose levels
7
Q
Hunger
A
the drive to satisfy the need for food
8
Q
Macronutrients
A
the essential nutrients required by the body in large amounts
9
Q
Mechanical digestion
A
the use of physical force to break down food, such as chewing or the squashing movement of the intestines
10
Q
Satiety
A
a state or feeling of fullness after eating food
- lower GI foods help satiety and help to stop people from overeating leading to obesity
11
Q
Saturated fats
A
contain the maximum amount of hydrogen
12
Q
Sensory appreciation of food
A
the information humans get from their senses about food and how they interpret that information
13
Q
Sensory properties of food
A
the characteristics of foods as they are perceived by the senses - sight, smell, taste, touch and hearing
14
Q
Trans fats
A
created artificially by a process called hydrogenation
15
Q
Unsaturated fats
A
can be monounsaturated or polyunsaturated fats
16
Q
How does hunger differ from appetite?
A
hunger is the drive to satisfy the need for food where as appetite is the desire for food even when the body is not hungry
17
Q
Examples of high and low satiety foods
A
high: meat, fish, poultry, dairy foods
low: snack foods, pastries, sweet biscuits, potato chips
18
Q
Relationship between satiety, appetite and the sensory appreciation of food
A
first your appetite has a desire for food, then your sensory appreciation of food and then satiety as you feel full after eating food
19
Q
Why is digestion important?
A
broken down into substances that can be absorbed and used by the body for energy, for growth and to build and repair new tissue
20
Q
Examples of mechanical digestion
A
- action of teeth and tongue
- muscular action in the oesophagus
- churning action of the stomach
- muscular action in the small and large intestines
21
Q
Examples of chemical digestion
A
- action of saliva in the mouth
- release of gastric juices in the stomach
- action of gastric juices and enzymes in the small intestine from the pancreas, liver and gall bladder
22
Q
Digestive actions of looking at and smelling food
A
- the mouth to water- saliva is produced
- the stomach to contract causing hunger pangs
- intestinal glands to start the production of digestive chemicals
23
Q
Functions of the digestive tract: mouth
A
- ingests food
- chews and mixes food with saliva
- begins the chemical breakdown of carbohydrates, due to salivary amylase (starch)
- moves food into the pharynx
- begins the breakdown of lipids
24
Q
Functions of the digestive tract: oesophagus
A
- propels food to the stomach, due to peristaltic waves
25
Functions of the digestive tract: stomach
- mixes food with gastric juices to form chyme
- begins the chemical breakdown of proteins
- absorbs some fat- soluble substances
26
Functions of the digestive tract: small intestine
- mixes chyme with digestive juices
- enables digestion and absorption to occur
- absorbs the breakdown products of carbohydrates, proteins, lipids and water
- performs physical digestion
27
Functions of the digestive tract: large intestine
- contains intestinal bacteria, which produces enzymes that metabolise several vitamins; this involves the synthesis of vitamin K, vitamin B12, folic acid and thiamine
- further breaks down food residues
- absorbs most water, electrolytes and vitamins
- aids faeces movement towards the rectum
- eliminates faeces
28
What is the primary digestive organ?
small intestine
29
Chemical/ mechanical actions of the stomach
- the stomach wall churns the bolus and the wavelike contractions squeeze the thick mass along to the first section of the small intestine - the duodenum
- a liquefied mass called chyme is produced
- the stomach juices containing pepsin begin the chemical digestion of proteins into amino acids
- hydrochloric acid helps to destroy bacteria
30
Sugars in the small intestine
Secretes in the small intestine
- sucrase breaks down sucrose to glucose
- lactase to break down lactose to glucose and galactose
- maltase to break maltose to glucose
31
Liver and pancreas in digestive process
the pancreas secretes both digestive juices and insulin. insulins helps to regulate the amount of sugar in the blood
- the liver produces bile, which is secreted into the duodenum where it emulsifies fat
32
What are villi?
the finger-like folds that project into the small intestine and increase the surface area to a size equivalent to a tennis court
damage to the villi prevents the absorption of other nutrients, leading to a state of severe malnutrition
33
Structure of villi
the surface of each villus is surrounded by a wall of single cells that allows nutrients to pass through
within each villus is a network of blood capillaries linking to veins and an artery
glucose is absorbed through the blood capillaries and circulated throughout the bloodstream
34
Glycaemic index on satiety
low GI foods prolong digestion because of their slow breakdown and will help give a sensation of feeling full
35
Low GI foods
- wholemeal pasta
- wholemeal bread
- soya beans
- kidney beans
- lentils
- brown rice
36
High GI foods
- white bread
- white rice
- soft drink
37
Carbohydrates used for energy
- carbohydrate is the bodies main source of energy
- sugars and starches are broken down to glucose during digestion
- the glucose is absorbed into the blood capillaries and transported by the bloodstream to cells in other parts of the body
38
Monosaccharides
- single units of sugar, they form the base of other carbohydrates
- glucose - provides energy
- fructose - simple sugar found in fruit
- galactose - found in milk
39
Disaccharides
- formed when two monosaccharides join together
- sucrose - glucose/fructose - sugar
- lactose - glucose/galactose - milk
- maltose - two parts glucose
40
Polysaccharides
- large, complex carbohydrates made from many sugar units, known as starches
- converted into glucose for energy
- starches are mainly found in cereals and starchy vegetables, such as potatoes
41
Why resistant starch is valuable in the digestive process
resistant starch resists digestion and promotes the groeth of healthy bacteria
42
What are microflora?
bacteria in the intestinal tract (small and large intestine) containing over 400 species and over 100 trillion individual microflora
43
How are microflora important in the digestive system?
-microflora/ bacteria perform many important and useful metabolic and fermentation activities in the
intestine
-they improve digestion and the absorption of short chain fatty acids and assist with the synthesis of Vitamin B and K
-they are particularly important in aiding the digestion
of lactose, reducing diarrhoea in lactose-intolerant people
44
Complete proteins & examples
come mainly from animal sources and contain all the essential amino acids required for growth and repair
eg- meat, fish, eggs, cheese, milk and yoghurt
45
Incomplete proteins & examples
lack one or more of the essential amino acids and do not contain all the essential amino acids for growth and repair of body tissues
eg- cereals, wheat, oats, rye, peas, beans, lentils and nuts
46
Probiotics and examples
live microbial food supplements, which when added to foods enhance nutrition, absorption from the bowel to protect the bowel against cancer and other disorders
eg- yoghurt, sauerkraut, miso, kombucha
47
Prebiotics and examples
compounds in food products that are non-digestible, these compounds stimulate the growth or activity of naturally occuring colonic bacteria thereby improving the health of the body
eg- garlic, onions, leeks, bananas
48
Absorption and utilisation of Carbohydrates
1. Salivary amylase -
Mouth: moves through the oesophagus, then enters the stomach, where it is recognised as CHYME. Salivary glands secrete saliva, which helps to moisten the food. At the same time food is being chewed, the salivary
glands are secreting salivary amylase, which begins breaking down carbohydrates into polysaccharides.
2. Pancreatic amylase -
Small intestine: (pancreas releases the enzyme) This breaks down polysaccharides into disaccharides
3. Sucrase, Lactase, Maltase (breaking down disaccharides into monosaccharides) -
Intestinal epithelial: cells of the small intestine
Break down sucrose to glucose (Sucrase)
Lactose to glucose and galactose (Lactase)
Maltose to glucose(Maltase)
These can then be used by the body for energy
49
Absorption and utilisation of Protein
1. Stomach releases gastric juices containing pepsin -
Stomach: Begins the breakdown of Protein bonds (broken down into peptides)
2. Protease ( a pancreatic enzyme) -
Small intestine: Splits the proteins into separate amino acids (breaks the peptides down into even smaller peptides) (Enzymatic hydrolysis)
50
Absorption and utilisation of Fats
1. Lipase (in saliva) -
In the mouth: Begins to emulsify fat and moistens the
food to make it easier to swallow.
(chemical digestion- not broken down yet)
2. Bile -
Duodenum: (bile is released from the liver)
Bile is an acid that breaks down fats (emulsifies- breaking down)
3. Pancreatic lipase -
Small intestine: (released from the pancreas)
Digests fats producing fatty acids and glycerol (those that are not secreted are passed out as waste)
51
Food allergy
An abnormal immunological reaction to food caused by a foreign substance, usually protein and can be life- threatening
52
Food intolerance
A chemical reaction to particular foods; it is not an immune response, so is not a true allergy
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Gluten intolerance/ Coeliac disease
A disease of the small intestine, the part of the digestive system responsible for absorbing nutrients. In a person who suffers from coeliac disease, the lining of the small intestine is damaged by gluten.
54
Lactose intolerance
Milk and other dairy products contain a sugar called lactose. For lactose to be digested in the body, it must first be broken down in the small intestine by the enzyme lactase.
55
Foods associated with intolerances
```
Chocolate
Milk
Wheat
Mint
Garlic
Mushrooms
Certain fruits
Fruit drinks containing preservatives
```
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Alternative foods for intolerances
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Corn
Rice
Buckwheat
Soy
Lentils
```
57
Foods associated with food allergies
```
Fish
Shellfish
Nuts
Eggs
Dairy foods
```
58
FODMAP diet (fermentable oligosaccharides, disaccharides, monosaccharides and polyols)
Describes a group of short-chain carbohydrates including lactose, fructose, fructans, galactans and polyols that may be poorly absorbed in the small intestine of some people. High FODMAP foods include vegetables high in fructans and dairy foods high in lactose etc
59
Food poisoning
An illness caused by consuming foods contaminated by bacteria, toxins or a virus
60
Food spoilage
A reduction in a foods quality identified by deterioration in its physical, chemical and/or sensory properties
61
Conditions required for bacterial growth (FAT TOM)
```
Food
Acid
Time
Temperature
Oxygen
Moisture
```
62
How to prevent food poisoning
Personal hygiene
Cleanliness of premises
Pest control
Storage of ingredients
63
Why is it important to ensure that food premises are free of pests
Insects can eat holes in the packaging material, leaving their faeces and body parts in the food and producing "off" odours in the food
64
Safe food handling practices
```
Wash hands
Don't wear jewellery
Wear apron
Keep fingernails short
Tie hair back
Sanitise and cover cuts
```
65
BACTERIA
| Salmonella - How is it spread, main symptoms/effects, foods found in
Causes an infection when food that contains live bacteria from contaminated food products, water or hands is eaten.
Nausea, diarrhoea, fever, headache, abdominal cramps
Raw meat, poultry, sausages, dry egg powder and mayonnaise
66
BACTERIA
| Listeria- How is it spread, main symptoms/affects, foods found in
Caused by eating food that contains listeria monocytogenes bacteria. Grow in refrigeration and can survive the pasturation process.
Miscarriage/stillbirth, food borne disease listeriosis can result in death
Milk products, soft cheese (brie, feta, camembert)
67
TOXIN
| Bacillus Cereus- How is it spread, main symptoms/affects, foods found in
A spore- forming bacterium that produces toxins that cause food poisoning.
Bacillus cereus infection, nausea, vomiting, diarrhoea
Cereals, boiled rice, vegetables high in starch (potatoes)
68
VIRUS
| Hepatitis A- How is it spread, main symptoms/affects, foods found in
Transferred from the faeces of an infected person and contaminates food, drinks or food-handling equipment through poor hygiene practices.
Viral infection of the liver, fever, nausea, abdominal pain, dark urine, jaundice
Fresh food that uses water in production, fruit/vegetables, frozen foods, shellfish
69
Australian dietary guidelines
Developed to guide and promote good nutrition and health, and reduce diet- related diseases.
70
Discretionary food choices
Food and drink that do not necessarily provide nutrients the body needs
71
Energy-dense foods
Foods that are high in energy, usually because of their high fat and sugar content
72
Kilojoule
A unit for measuring energy intake
73
Lifestyle diseases
Diseases such as obesity, type 2 diabetes and cardiovascular disease
74
Baking
The cooking of food in an oven without the addition of fat or oil
75
Blanching
Partly cooking food by plunging it briefly into boiling water
76
Boiling
Cooking food in water at 100c
77
Conduction
Occurs when heat is transferred from one molecule to another by collision or movement
78
Convection
Occurs when the molecules in liquids or gases move from a warmer area to a cooler one
79
Cooking
Application of heat to ingredients to cause physical and chemical changes
80
Frying
Cooking food by total or part immersion in fat or oil that is heated to temperatures between 150c and 220c
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Grilling
A fast, dry method of cooking that uses intense heat radiated by an electrical element, a gas flame, glowing charcoal or an open wood fire
82
Poaching
A method of cooking delicate foods in a liquid just below simmering point (85c)
83
Radiation
The transmission of heat energy in the form of rays, as occurs during grilling and microwaving
84
Roasting
The cooking of food in an oven using an amount of fat or oil
85
Simmering
Cooking food at a temperature of 85c
86
Steaming
Cooking food in the steam from boiling water
87
Stewing
A long, slow method of simmering food in a small amount of liquid
88
Aeration
The process of incorporating air into food products to increase the volume and create a light, airy texture
89
Caramelisation
The process that sugars undergo when heated to high temperatures to develop a golden brown colour
90
Coagulation
A form of denaturation and occurs when there is a permanent change in the protein from a liquid into a thick mass as a result of heat or the addition of acids
91
Denaturation
The permanent structural change of the protein molecules in food
92
Dextrinisation
The process that occurs when starch is exposed to dry heat; the starch is broken down to dextrin, resulting in a change in colour to golden brown
93
Emulsification
Mixing two liquids that don't normally combine evenly, for example water and oil
94
Functional properties
The physical and chemical properties of ingredients that impact on food preparation and processing
95
Gelatinisation
The process that occurs when starch granules absorb liquid in the presence of heat and thicken the liquid, forming a gel
96
Maillard reaction
Occurs when a protein and a sugar or starch are present in the same mixture and dry heat is applied during baking, creating a golden brown crust
