Enzymes and Digestion Flashcards
What are the seven food groups? How do you remember these?
carbohydrates (starch and gluose)
protein
lipids (fats and oils)
fibre
vitamins
minerals
water
Careless Pauline Let Finnian Vaporise My Water
What are simple sugars called?
monosaccharides
What are complex sugars called?
polysaccharides
What is starch made of?
thousands of glucose molecules
Give an example of a simple sugar (monosaccharide)
glucose
Give an example of a complex sugar (polysaccharide)
starch
What are carbohydrates?
they include simple sugars (monosaccharides) such as glucose and complex sugars (polysaccharides) such as starch (which is made of thousands of glucose molecules)
What are elements of glucose?
Carbon
Hydrogen
Oxygen
(C, H, O)
What is the formula for glucose?
C6H12O6
What is the equation for respiration?
glucose + oxygen —> carbon dioxide + water + ATP
C6H12O6 + 6O2 —> 6CO2 + 6H2O + ATP
What is the function of glucose?
short-term energy supply which is used in respiration
What are some sources of glucose?
e.g. in fruits, sweets
What are elements of starch?
Carbon
Hydrogen
Oxygen
(C, H, O)
What is the structure of starch?
thousands of glucose molecules
What is the function of starch?
short-term energy storage which is broken down into glucose for respiration
What is the function of starch in plants?
stores starch
What is the function of starch in humans?
eat foods containing starch which broken down into glucose in digestion
What are some sources of starch?
e.g. in bread, potatoes, pasta, rice
If you need a quick burst of energy what food should you eat and why?
eat food containing glucose (instead of starch) as it doesn’t need to be digested and can be absorbed into the bloodstream directly
What are the elements of protein?
Carbon
Hydrogen
Oxygen
Nitrogen
Sulphur
(C, H, O, N, S)
What is the structure of proteins?
chains of amino acids (20 different types)
What is the function of proteins?
there are a variety of functions:
needed to maintain cell function
needed to grow and repair cells and tissues
What are some sources of proteins?
e.g. meat, fish, eggs, dairy
What is the function of proteins in enzymes?
enzymes speed up chemical reactions in your body, e.g., the breakdown of food or respiration
What is the function of proteins in muscles?
muscle proteins called actin and myosin enable all muscular movement
What is the function of proteins in cellular messengers?
receptor proteins on the cell membrane transmit signals to other proteins inside cells
What is the function of proteins in antibodies?
antibodies are proteins that help defend your body against harmful microbes
What is the function of proteins in hairs and nails?
a protein called keratin forms your hair and fingernails
What is the function of proteins in the brain and nerves?
ion channel proteins control nervous system signalling by allowing ions in and out of nerve cells
What is the function of proteins in blood?
the haemoglobin protein carries oxygen in your blood to every part of your body
Complete this gapfill:
Lipids are good for … energy … - the body generally uses … first and stores … and …. If we run out of … our body breaks down the … and uses it as fuel for … - it is like a reserve energy source
Lipids are good for long-term energy storage - the body generally uses carbohydrates first and stores lipids and fat. If we run out of carbohydrates our body breaks down the fat and uses it as fuel for respiration - it is like a reserve energy source
What are the elements of lipids?
Carbon
Hydrogen
Oxygen
(C, H, O)
What are the subunits of lipids?
glycerol and three fatty acids
What is the function of lipids?
long-term energy storage
What are the types of lipids?
they include fats (solid at room temperature) and oils (liquid)
What are some sources of lipids?
e.g. butter, dairy, oil, nuts
What are some sources of lipids (fats)?
e.g. butter
What are some sources of lipids (oils)?
e.g. olive oil
What are elements of fibre?
Carbon
Hydrogen
Oxygen
(C, H, O)
What is the structure of fibre?
thousands of glucose molecules
What is the function of fibre in plants?
makes up plant cell walls (cellulose)
What is the function of fibre in humans?
humans cannot digest fibre, but eating fibre helps to keep the digestive system healthy and to prevent constipation
What are some sources of fibre?
e.g. vegetables, fruit
What is fibre made of?
CHECK
What are minerals?
inorganic substances (salts) needed by the body in small amounts
What are some examples of minerals?
calcium, iron, magnesium, iodine
What is the function of minerals (calcium)?
to make healthy bones
What is the function of minerals (iron)?
blood - needed to make haemoglobin (molecule in Red Blood Cells)
What are some sources of minerals (calcium)?
e.g. milk
What are some sources of minerals (iron)?
e.g. meat and liver
What are vitamins?
organic substances needed by the body in small amounts
What are some examples of vitamins?
Vitamin A, Vitamin C, Vitamin D
What is the function of vitamins?
to take part in important chemical reactions in the body
What are some sources of vitamins (Vitamin A)?
e.g. carrots
What are some sources of vitamins (Vitamin C)?
e.g. oranges and lemons (citrus fruit)
What are some sources of vitamins (Vitamin D)?
e.g. milk
How much of the body is water?
about 67%
What is the formula for water?
H2O
What is the function of water?
to carry substances around the body and replace lost water
What are some sources of water?
e.g. drinks, vegetables (cucumber which is 95% water and tomatoes)
What is the function of carbohydrates?
short-term energy supply
What is the function of protein?
cell function, growth and repair of cell tissues
What is the function of lipids?
long-term energy storage and supply
What is the function of fibre?
to keep the digestive system healthy and prevent constipation
What is the function of vitamins?
to take part in important chemical reactions in the body
What is the function of minerals?
to make healthy blood, bones and other tissues
What is the function of water?
to carry substances around the body and replace lost water
Complete this gapfill:
We can test for glucose using …. If glucose is present, the colour will change from … to … when heated.
What should you use to heat for the colour change to happen?
We can test for glucose using Benedict’s reagent. If glucose is present, the colour will change from blue to brick red when heated.
To heat, use a bunsen burner or water bath
What is the colour gradient for the amount of glucose present when tested with Benedict’s reagent (from a lot of glucose present to little)?
red
orange
yellow
green
blue
Complete this gapfill:
We can test for starch using …. If starch is present, the colour will change from … to …/…
We can test for starch using iodine. If starch is present, the colour will change from brown to blue/black
Complete this gapfill:
We can test for protein using … (= copper sulphate + sodium hydroxide). If protein is present, the colour will change from … to …
We can test for protein using Biuret reagent (= copper sulphate + sodium hydroxide). If protein is present, the colour will change from light blue to purple
The substance tested for is starch. Complete the table:
Solution used:
Colour of solution at start:
Colour of solution at end:
Heat required?:
Solution used: iodine
Colour of solution at start: yellow
Colour of solution at end: blue/black
Heat required?: no
The substance tested for is glucose. Complete this table:
Solution used:
Colour of solution at start:
Colour of solution at end:
Heat required?:
Solution used: Benedict’s reagent
Colour of solution at start: blue
Colour of solution at end: red
Heat required?: yes
What is a balanced diet?
the right balance of different food groups providing the body with all essential nutrition and the right amount of energy (calories)
What is malnutrition?
a condition resulting from eating a diet that does not contain the right amount of nutrients
it happens when your diet is unbalance long-term
What is undernutrition and starvation?
not ontaining enough nutrients/calories
What are the causes of undernutrition and starvation?
e.g. not eating enough
What are the symptoms of undernutrition and starvation?
underweight
weakness
loss of fat and muscle tissue
What is overnutrition and obesity?
taking in too many nutrients/calories
What are the causes of overnutrition and obesity?
overeating
genetic
What are the symptoms of overnutrition and obesity?
weight gain
excess fat
heart disease
diabetes
What is BMI?
(body mass index)
= a measure of body fat based on height and weight
Who does BMI apply to?
adult men and women
How do you calculate BMI?
weight (kg) ÷ height (m)2
What are the BMI values for adults?
<18 underweights
18-25 normal weight
>25 overweight
>30 obese
How can we know if someone is overweight or obese?
calculate their BMI
however, BMI is not always useful as it is only fine for average people
What are deficiency diseases?
not enough of a particular food group (i.e. unbalanced diet)
What are some deficiency diseases?
night blindness
scurvy
rickets
anaemia
kwashiorkor
goitre
What are the causes of night blindness?
deficiency in Vitamin A —> degeneration of rod cells in the retina
rod cells enable us to see
What are the symptoms of nighblindness?
poor vision in low light levels
What is the cause of scurvy?
deficiency in Vitamin C
What are the symptoms of scurvy?
poor wound healing
bleeding, particularly in gums
loss of teeth
fatigue
What are the causes of rickets?
deficiency in Vitamin D or calcium; lack of sunlight
What are the symptoms of rickets?
brittle bones
bow legs
poor teeth
What is the cause of anaemia?
deficiency in iron
the body will lack Red Blood Cells and won’t be able to transport oxygen efficiently
What are the symptoms of anaemia?
low energy levels
lethargy
dizziness
What is the cause of kwashiorkor?
deficiency in protein
What are the symptoms of kwashiorkor?
swollen belly
poor muscle growth
weight loss
What is the cause of goitre?
deficiency in iodine
What are the symptoms of goitre?
swollen lump in thyrdoid glanf
slow metabolism
What is the energy in food used for?
movement, body heat and growth
What is the energy process for eating food?
food (chemical energy) —> respiration —> movement (kinetic energy), body heat (heat energy), growth and repair (chemical energy)
What happens if you take in too much energy?
you gain weight
What happens if you take in too little energy?
weight loss
What does how much energy we need depend on?
activity levels
temperature
age
What does one calorie equate to?
1 calorie = quantity of heat energy required to raise the temperature of 1g of water by 1oC
What is the equation for 1 joule?
1 joule = 4.2 x calories
(e.g. 100 cal = 420J)
What is the equation for food energy (calories)
food energy (calories) = mass of water (g) x temperature rise (oC)
What is the equation for food energy (calories ÷ grams)
food energy (calories ÷ grams) mass of water (g) x temperature rise (oC) ÷ mass of food
Do you think the BMI is always a good measure of obesity?
no
it is only good for average people
it cannot, e.g., take into account muscle weight
How could you treat deficiency symptoms?
taking supplements
incorporate the deficiency into your diet –> eat more e.g. Vitamin A if you suffer from night blindness
Why do you think scurvy was particularly prominent amongst sailors?
cannot eat fresh fruit (e.g. oranges) as they do not have access to them
Why would people suffering from anaemia have low energy levels and feel dizzy?
deficiency in iron —> body will lack Red Blood Cells and won’t be able to transport oxygen efficiently —> lack of oxygen for respiration
What kind of people might be at risk of developing Kwashiorkor in the UK?
vegans (although they can take B12 supplements)
people with an unbalanced diet
Who needs more energy and why?
male or female
male
on average their proportions are bigger