food tech GCSE

What is protein needed for?

-growth (e.g. nail/hair growth)

-repair (repairing muscles after illness/ injury)

-maintenance (e.g. making enzymes for digestion)

What are non-essential amino acids?

amino acids our bodies can make

What are essential amino acids?

amino acids we have to eat

What are HBV proteins?

-high biological value

-contain all the essential amino acids we need

-found in meat, fish, poultry, eggs, cheese, milk, soya beans, quinoa

What are LBV proteins?

-low biological value

-missing 1+ essential amino acids

-only found in plant sources (peas, lentils, nuts, seeds)

What is protein complementation?

-the combination of different LBV proteins to get all the essential amino acids (pitta+hummus)

How much more protein do pregnant women need?

6g more to help baby grow/more when breastfeeding

What can an excess of protein lead to?

Puts pressure/ strain on the organs processing proteins (liver, kidneys), which can be dangerous

What can a deficiency of protein lead to?

-growth is slowed down

-immune system can't work properly (wounds don't heal as fast, more infections)

-can lead to oedema

What is oedema?

-caused by deficiency of protein

-a build up of fluid in the body that causes swelling (often around the feet)

What is soya?

-alternative protein

-plant based HBV protein

-Must be cooked to remove toxicity

What is mycoprotein?

-alternative protein

-traditionally made from a mushroom like fungus and egg white

-Tthere are now vegan alternatives that use potato starch

What is TVP?

-textured vegetable protein

-made from soya beans (soya flour)

-soya flour is used to make a dough which when baked has a meat like texture

What do fats provide?

-concentrated energy

-nutrients (fat soluble vitamins such as vitamins A, D, E, K)

-bodies use fat to make cholesterol (essential part of cell membranes)

What are fats made of?

-triglyceride (1 glycerol and 3 fatty acids)

-fatty acid chains are made of carbon and hydrogen

Are saturated fats healthy or unhealthy?

-unhealthy (especially in large amounts)

-too much saturated fat in the diet can increase cholestorol levels in the blood (increased risk of CHD)

What are saturated fats?

-solid at room temperature

-generally from animal sources

Are unsaturated fats healthy or unhealthy?

-generally healthier

-generally soft/liquid at room temperature

-replacing saturated fats with unsaturated has been shown to lower blood cholesterol

Where are unsaturated fats found?

-from vegetable sources

What are monounsaturated fats?

-contain one C=C double bond in their carbon chains

-found in olive oil, almonds, peanut butter, avocados

What are polyunsaturated fats?

-contain more than one C=C double bond

-found in sesame oil, soybean oil, seeds and oily fish

What percentage of our daily food energy should fat make up?

less than 35% (less than 11% from saturated)

How many grams of fat should an average adult consume?

70g (max 20g from saturated)

What can an excess of fat lead to?

-too much saturated fat can increase blood cholesterol levels

what can increased blood cholesterol levels lead to?

-cholesterol builds up in blood vessels and restricts blood flow around body

-increases the risk of high blood pressure, strokes, heart attacks, and CHD

what can a deficiency of fat lead to?

- Less fat soluble vitamins are absorbed by the body

What are fat soluble vitamins?

A, D, E, K

What are sugary carbohydrates?

-e.g. glucose, fructose

-can be divided into monosaccharides and disaccharides

What are starchy carbohydrates?

-contain lots of nutrients such as B vitamins, iron and calcium

-wholegrain starch foods have a really high fibre content

What are monosaccharides?

-simple carbohydrates (sugar)

-the most basic sugar molecules

-e.g. glucose, fructose

What are disaccharides?

-simple carbs (sugar)

-made up of 2 monosaccharides

-e.g. sucrose (made of glucose and fructose)

What are polysaccharides?

-complex carbohydrates, including starchy carbs

-take longer to digest, providing a slower release of energy

-made of lots of monosaccharides joined together

What does the body do to simple carbs?

-rapidly digests them

-making blood sugar levels rise quickly

-providing a short burst of energy

What is the glycaemic index?

-GI

-rates carbohydratres on how quickly they affect blood sugar levels

-helpful to people with diabetes (allows them to choose low GI carbs to avoid surges in blood sugar levels)

How much of our energy should come from carbs?

-50%

What happens if we have an excess of carbs?

-Will convert into fat

-tooth decay

-can lead to type 2 diabetes

What can a deficiency in carbs lead to?

-blood sugar levels drop, can cause hunger, dizziness, and tiredness

-body will use another source of energy, stored fat

-if you also have a fat deficiency, our bodies use up proteins, causing us to lose muscle, making us weaker.

What is vitamin A used for?

-good eyesight (night vision)

-growth

-healthy immune system

-healthy skin

-antioxidant

What are sources of vitamin A?

-retinol (liver, butter, oily fish, eggs)

-can be made from carotene (margarine, orange/yellow fruit/veg)

What can an excess of vitamin A lead to?

-can weaken bones

-should be avoided during pregnancy

What can a deficiency of vitamin A lead to?

-night blindness

-weaker immune system

-stunted growth

What is vitamin D used for?

-helps the body absorb various mineral (e.g. calcium)

-so helpful for the development of healthy bones+teeth

Where is vitamin D found?

-oily fish

-egg yolks

-produced when the skin is exposed to sunlight

What can an excess of vitamin D lead to?

-makes you absorb too much calcium (can lead to kidney damage)

What can a deficiency of vitamin D lead to?

-can lead to bone diseased (osteomalacia, rickets, osteoporosis)

What is osteomalacia?

softening of the bone

Why do you need vitamin E?

-keeps skin+eyes healthy

-improves immune system

-antioxidant (may protect us from free-radicals)

What are sources of vitamin E?

-leafy greens

-nuts

-vegetable oils

What can an excess of vitamin E do?

-can interfere with blood clotting

-cause nausea

-blurred vision

What can a deficiency of vitamin E lead to?

-weak muscles

-problems with sight

What does vitamin K do?

-helps blood clotting so heals wounds

-maintains immune system

-maintains bones

What are sources of vitamin K?

-leafy greens

-cereals

-vegetable oils

What can an excess of vitamin K lead to?

there is no excessive level of vitamin K

What can a deficiency of vitamin K lead to?

-extremely rare in adults

-can cause uncontrolled bleeding in newborns

What happens to unused fat-soluble vitamins?

stored in fat tissue

What are water-soluble vitamins?

vitamins that dissolve in water, aren't generally stored in the body, so we need to take them in daily

What are water soluble vitamins?

B and C (Before Christ, Christ walked on WATER)

What is the function of vitamin B?

-helps energy release from foods

-helps maintain a healthy nervous system

-Crucial for growth

What is the function of vitamin C (ascorbic acid)?

-protects the body from infection + allergies

-keeps blood vessels healthy + heals wounds

What can a deficiency in Vitamin B lead to?

-tiredness

-weak muscles

-beriberi (in severe cases)

What is beriberi?

-a disease that affects the heart, blood vessels and nervous system

What is pellagra?

-Vitamin B deficiency

-a disease causing fatigue, depression and loss of memory

What can a deficiency in vitamin C (ascorbic acid) lead to?

-anaemia

-scurvy (tiredness and bleeding gums)

-too little can increase the risk of cancer

What can an excess of vitamin C (ascorbic acid) lead to?

-stomach pain

-diarrhoea

Why should you prepare fruit/veg just before you need to use it?

because once they are exposed to air, they start losing vitamin C

Why shouldn't you leave your fruits/veg to stand in water?

-because vitamins B and C dissolve in water

-steaming/microwaving are the best ways to keep the water-soluble vitamins

What are free radicals?

-chemicals we encounter daily

-they can damage our body's cells

-leading to cancer/heart disease

What are antioxidants?

-vitamins A, C and E

-many people believe they protect us from free radicals

What is calcium needed for?

-strong bones+teeth (especially in growing children)

-healthy nerves and muscles

-blood clotting

What can an excess of calcium lead to?

-excess is stored in organs like the kidneys

-can increase the risk of kidney tones

-could even stop kidneys working

What can a deficiency of calcium lead to?

-too little in childhood can lead to rickets/osteoporosis as bones become weaker

-slow down blood clotting

What is iron needed for?

-to form part of haemoglobin (gives red blood cells their red colour)

What can an excess of iron lead to?

-can cause stomach pains/nausea

-constipation

-in extreme cases can cause death

What is sodium needed for?

-controls the body's water content

-helps our nerves+ muscles to function

What can an excess of salt lead to?

-lead to high blood pressure

-leads to heart disease

What can a deficiency of salt lead to?

-nausea

-muscle cramps

What is phosphorus needed for?

-healthy bones and teeth

What are sources of phosphorus?

-protein rich foods

-meat, fish, dairy products, nuts, beans, cereals

What can an excess of phosphorous do?

-can make it harder to absorb calcium

What can a deficiency in phosphorous lead to?

-weak muscles

-painful bone

What does flouride do?

-strengthens teeth

-hardens tooth enamel

-helps prevent tooth decay

What can an excess of fluoride lead to?

-brown coloured teeth

-bone problems

-cancer

What can a deficiency of fluoride lead to?

-weak teeth/enamel (leads to tooth decay)

What is iodine needed for?

to make some hormones in the body

What is iodine found in?

seafood, dairy foods and vegetables

What can a deficiency of iodine lead to?

-a serious lack of iodine can cause goitre (neck swelling)

-complications in new born babies

What can a lack of fibre lead to?

-constipation

-bowel/colon cancer

-high blood pressure

How much fibre do we need?

-average adult should have 30g a day

-young children need less as the "fullness" fibre gives people can stop them from eating more important nutrients

How much water is in our bodies?

-60%

-found in every cell

-found in fluids (blood, sweat, saliva)

Why do our bodies need water?

-Eliminates waste

-Controls body temperature (sweating)

-Aids the process of digestion

EATWELL GUIDE what fraction of your daily food intake should fruit/veg make up?

1/3 of your daily intake (at least 5 portions every day)

EATWELL GUIDE what fraction of your daily food intake should starchy carbs make up?

-1/3 of your daily intake (starchy food in every meal)

How much fluids should you have per day?

6-8 glasses (no more than 1 glass fruit juice a day)

How much salt should you have per day?

no more than 6g

Why is milk important to 2-5 year (young children) olds?

-gives children their daily calcium (although it is better to get from a range of foods)

-good source of vitamin A

-300ml a day

Why do 5-12 year olds (children) need carbs/fat?

-provide energy for growth/physical activity

-saturated fats should be eaten in moderation

Why do teens need protein?

-to cope with growth spurts

-boys tend to need more protein than girls as muscular tissue develops

Why do teens need iron/vitamin C?

-teenage girls lose iron when they have their period so it must be replaced or they could become anaemic

-vitamin C helps the body absorb iron

Why do teens need calcium/ vitamin D?

-skeleton grows quickly during this time

-these nutrients are neccesary as they help the skeleton reach peak size/bone density

Why is calcium/vitamin D important for adults/elderly?

-reduce the chance of bone diseases in later life

-women can quickly lose bone strength after menopause

-needed to keep the skeleton strong