Cada pergunta deste Quiz é cronometrada.
Which of these are functions of proteins in the human body?
Antibodies
Catalysts
Energy stores
Hormones
Toxins
Structural components
True or false? Enzymes have a specific shape called the active site so each enzyme can only catalyse one type of reaction.
Which of these provides the best description of the lock-and-key model of enzyme action?
When an enzyme finds a substrate, it releases tiny molecules which act as "keys" to the particular "lock" of the substrate, helping to catalyse the reaction.
When a substrate (the lock) comes into contact with the enzyme (the key) with the correct active site, the two chemicals form an enzyme-substrate complex which allows the reaction to be catalysed.
Enzymes block passageways in the body which can be only opened if the substrate comes and the reaction is catalysed.
Which of these are examples of reactions involving enzymes?
Breaking down large molecules into small molecules
Building large molecules from small molecules
Changing one molecule into another
Making molecules disappear
Causing molecules to diffuse across a partially permeable membrane
True or false? The optimum pH of action for any enzyme is always pH7.
True or false? If the core body temperature rises too much above 37°C (hyperthermia) then enzymes change shape and denature - they cannot catalyse any reactions.
Which of these enzymes are used in the digestion of starch?
Amylase and maltase
Protease
Lipase
What are the products of digestion of proteins?
Glucose
Amino acids
Fatty acids and glycerol
What are the products of digestion of lipids?
Which of these tests would you use to detect the presence of reducing sugars such as glucose?
Tollens' reagent
Benedict's reagent
Biuret reagent
Iodine test
Which of these are functions of bile?
Makes absorption of small soluble particles easier
Neutralises hydrochloric acid in the stomach and makes the conditions alkaline
Emulsifies drops of fat into smaller droplets, increasing surface area for enzyme action
Carries protease enzymes for digestion of protein
True or false? Pepsin is produced in the stomach because its optimum pH is around pH2.
True or false? Bile is an enzyme.
Which of these are advantages of using biological washing powders?
They run at lower temperatures so use less energy to heat the water
They can cause allergic reactions in some people
They can digest protein-based fabrics such as wool
They contain proteases which are effective in removing stains such as blood and sweat
Why do we use protease enzymes in baby foods?
To make the baby food taste more pleasant
To pre-digest proteins as babies have low levels of proteases
To remove biological stains such as sweat and blood
Which enzyme is used in slimming foods to convert glucose into fructose?
Amylase
Fructase
Zymase
Isomerase
Which of the following sugars is used in slimming foods as it has a sweeter flavour for the same level of sweetness and so is required in smaller amounts?
Mannose
Sucrose
Fructose
Lactose
True or false? There are concerns about using enzymes in industry because they may enter waterways with unknown effect on aquatic life.
Which of these are advantages of using enzymes in industry?
Can be used at low temperatures
Can be used at normal pressure
Can be used in the absence of water
Which of these are disadvantages of using enzymes in industry?
Money needed to control temperature and pH
Cannot be used in metal containers
Expensive to produce enzymes
