Human Nutrition Flashcards
1
Q
What foods do carbohydrates come from?
A
Bread
Rice
Potatoes
Pasta
—> all starchy foods
Fruits
Vegetables
2
Q
Function of carbohydrates
A
Fuel for energy (slow-release energy)
—> to carry out chemical reactions and to help us move around
3
Q
What foods do lipids come from?
A
Fats: meats, oily fish, dairy products, nuts and seeds, avocados
Oils: cooking oils e.g. olive oil, sunflower oil
4
Q
Function of lipids
A
Provide energy (longer term store of energy, we can store lots of fat for later use)
Keeps us warm by insulating
Protect our organs
5
Q
What foods do proteins come from?
A
Meat
Fish
Eggs
Cheese
Nuts and seeds
Legumes: lentils, beans
6
Q
Function of proteins
A
Building blocks
—> grow, repair damaged tissue/cells
Can be used for energy but only in emergencies if we don’t have enough carbs or lipids
7
Q
What can a protein defence cause?
A
Kwashiorkor
—> not common in developed countries
8
Q
How much of vitamins and mineral ions do we need?
A
Only a small amount
9
Q
What is a vitamin?
A
An organic molecule
10
Q
What does organic mean?
A
Made by living organisms
11
Q
What foods does vitamin A come from?
A
Meat
Liver
Dairy
Eggs
Leafy vegetables (spinach)
12
Q
Why is vitamin A important?
A
To make the retina for vision
For healthy skin and hair
13
Q
What can a vitamin A deficiency cause?
A
Night blindness
14
Q
What foods does vitamin C come from?
A
Citrus fruits
Strawberries
Green vegetables
15
Q
What is vitamin c a part of?
A
Collagen
—> so used to make skin, hair, nails, bones
16
Q
What does a vitamin C deficiency cause?
A
Scurvy
Bad breath
Loose teeth
Muscle and joint pain
Weight loss
Bruising
Swollen legs
Shallow breathing
Weakness
Sallow complexion
17
Q
Function of vitamin C
A
Helps wounds to heal
18
Q
What can the body make using sunlight?
A
Vitamin D
19
Q
What food does vitamin D come from?
A
Oily fish
Eggs
Dairy products
20
Q
Why is vitamin D needed?
A
To absorb calcium
21
Q
Why is vitamin D important?
A
For healthy bones and teeth
22
Q
What does a vitamin D deficiency cause?
A
Rickets
23
Q
What is a mineral?
A
An inorganic molecule
24
Q
What does inorganic mean?
A
Not made from living things
25
What food does calcium come from?
Eggs
Dairy products
Leafy vegetables
26
Why is calcium important?
For strong bones and teeth
27
What does it mean if you can’t absorb calcium?
You have a lack of vitamin D (deficiency)
28
What does a calcium deficiency cause?
Rickets (bones can be deformed)
Osteoporosis later in life
29
What food does iron come from?
Red meat
Liver
Leafy green vegetables vegetables (spinach)
Beans
30
Why is iron needed?
To make haemoglobin - helps red blood cells transport oxygen
31
What does an iron deficiency cause?
Anaemia - can’t transport as much oxygen to your tissues
32
Symptoms of anaemia
Shortness of breath
Tiredness
33
What is a fibre?
A type of carbohydrate
—> we don’t absorb it into the body
34
What food does fibre come from?
Whole meal bread
Brown rice
Fruits
Vegetables
35
Function of fibre
To help move food through our intestines properly
Stops us getting diarrhoea and constipation
36
Where do we get water from?
Drinks
Oranges, strawberries - mostly water
37
Why do we need water?
For chemical reactions
Body is about 70% water
Continuously losing water so have to replace it all
38
What are ways we lose water?
Breathing
Sweating
Urinating
39
What 3 main factors affect how much energy we need each day?
Activity level
Age
Pregnancy
40
Activity level (how much energy we need each day)
The more your are active the more energy you need
41
Why do teenagers often need a lot of energy
They’re growing
—> why elderly people need less
42
Why should a pregnant lady or athlete consume more energy rich foods than someone who works in an office?
Higher energy requirements
—> they use more energy
43
What is digestion?
Process by which large food molecules that we eat are broken down into smaller, simpler and more soluble molecules to be absorbed
44
Why are enzymes important for digestion?
They speed up digestion reactions
45
Which enzymes breaks starch down into maltose?
Amylase
46
What is starch?
A polymer of glucose
47
What is maltose?
2 glucose molecules stuck together
48
Which enzymes breaks maltose down into glucose?
Maltase
49
Why do carbs need to be broken down into glucose?
So they are small enough for our body to absorb
50
Where is amylase produced?
Salivary gland
Pancreas
Small intestine
51
Where does amylase act?
Mouth
Small intestines
52
Where is maltase produced?
Pancreas
Small intestine
53
Where does maltase act?
Small intestine
54
Which enzyme breaks proteins down into amino acids?
Protease
55
What are carbs fully broken down into?
Glucose
56
What is protease?
A group of enzymes
57
What does pepsin break stuff down into?
Protein —> peptides
58
Where is pepsin produced and where does it act?
Produced: stomach
Acts: stomach
59
What does trypsin break stuff down into?
Protein —> peptides —> amino acids
60
Where is trypsin produced and where does it act?
Produced: pancreas, small intestine
Acts: small intestine
61
What does peptides break stuff down into?
Peptides —> amino acids
62
Where is peptides produced and where does it act?
Produced: pancreas, small intestine
Acts: small intestine
63
Which enzyme breaks down lipids into glycerol and fatty acids?
Lipase
64
What is protein broken down into?
Amino acida
65
What are lipids broken down into?
Glycerol
Fatty acids
66
What helps in the breakdown of lipids?
Bile
Emulsifies the lipids
67
What does emulsification mean?
Bile breaking up big droplets of lipids (fats) into lots of little droplets
—> increases the surface area for the lipase enzymes to break down the lipids
68
Where is lipase produced?
Pancreas
Small intestine
69
Where does lipase act?
Small intestine
70
What is digestion done by?
Physically: teeth, stomach
Chemically: enzymes
71
What is absorption?
Process by which we absorb these small molecules (also vitamins, minerals and water)
—> from the digestive tract into the bloodstream to be sent around the body to be used
72
Where does ingestion occur?
The mouth
73
The mouth (digestion)
Taking in food into the digestive system
74
75
What do our teeth do when eating?
Physically breakdown food by chewing
Increases the surface area of the food
—> easier for our enzymes to break it down
76
What do the salivary glands do?
Release saliva
Chemical breakdown by saliva
77
Which enzyme does saliva contain?
Amylase (biological catalyst)
—> digests starch into maltose
78
The oesophagus (digestion)
Food passes through here to reach the stomach
Food moves by peristalsis
79
What is the wave of muscle contraction that pushes food through the gut called?
Peristalsis
—> allows us to swallow/drink upside down
80
The stomach (digestion)
1) muscular walls contract to mix the food (mechanical breakdown)
2) produces pepsin: breakdown protein into amino acids (chemical breakdown)
3) produces hydrochloric acid - kills bacteria, provides the right pH for the pepsin enzyme to work
81
What does hydrochloric acid in the stomach do?
Kill bacteria
Provide the right pH for the pepsin enzyme to work
82
The pancreas (digestion)
Releases pancreatic juices into the small intestine
83
What is the pancreatic juice?
A liquid mixture: amylase, protease, lipase, maltase
Also neutralises stomach acid
84
The liver and gall bladder (digestion)
Liver produces bile
Gall bladder stores the bile and releases it into the small intestine
85
What does the gall bladder do during digestion?
1) neutralises the acid from the stomach
2) emulsifies lipids (gives them a larger surface area)
86
What is bile?
A green, alkaline liquid that neutralises stomach acid
87
The small intestine (digestion)
Where most of the digestion takes place
Releases digestive enzymes - carbohydrase, protease, lipase (chemically digest food)
—> nutrients are broken down
The lining has a large surface area for absorption or nutrients
88
What is the lining of the small intestine covered in?
Villi (villus)
89
Function of the villi
Huge surface area for diffusion
Single sayer of surface cells (very short diffusion distance)
Have a really good blood supply - maintains the concentration gradient for the absorption of nutrients
90
What do the cells of the villi have?
Their own microvilli
—> further increases the surface area
91
What is the first part of the small intestine called?
Duodenum
Accepts: food from the stomach, bile from gall bladder, enzymes from pancreas
92
What is the second part of the small intestine called?
Ileum
Where a lot of digestion and absorption occur
93
The large intestine (digestion)
Absorbs most of the excess water
Leaves behind indigestible food called faeces to be excreted
Rectum stores the faeces
94
The anus (digestion)
Ring of muscle
Relaxes to release faeces - called egestation
95
Pathway of digestion
Ingestion
Digestion
Absorption
Assimilation
Egestion
96
What is ingestion?
Taking in of food into the digestive system
97
What is assimilation?
Small molecules are built up into larger ones (basically the opposite of digestion)
98
What is egestion?
Excreting indigestible material
99
Why does bile need to be alkaline?
To neutralise stomach acid
100
Why does bile need to do emulsification and neutralisation?
To give optimum pH and large surface area for enzymes
101
Which component of a balanced diet helps peristalsis in the gut and prevents constipation?
Fibre
102
Which component of a balanced diet is used to release energy by respiration?
Carbohydrate
103
Which component of a balanced diet is important for growth and repair?
Protein
104
Which component of a balanced diet stores energy, is used in cell membranes and as insulation?
Lipids
105
Which component of a balanced diet forms a pigment important for vision?
Vitamin A
106
Which component of a balanced diet makes up 80% of your cytoplasm?
Water
107
Why does the small intestine have villi and microvilli?
So it has more surface area for absorption of nutrients
108
What route does food take through the digestive system?
Mouth
Oesophagus
Stomach
Small intestine
Large intestines
Rectum
109
Word equation for photosynthesis
Carbon dioxide + water —> glucose + oxygen
110
What is the chemical formula for glucose?
C6H12O6
111
Which cells carry out the most photosynthesis?
Palisade mesophyll
