Chapter 3 - Enzymes Flashcards
List two proteins found inside living organisms ?
Actin and Myosin
Inside muscle cells allow them to contract
Describe the structure of protein molecules ?
formed form chains of Amino acids
which then fold and coil into a special shape
Define the term catalyst ?
A substance which speeds up a chemical reaction
At the end of the reaction the catalyst is chemically un changed
Define the term enzyme
Protein molecules which act as biological catalysts
They change the ate of chemical reactions without being affected at the end of the reaction
Why are some enzymes denatured by high temperatures ?*
The heat damages the shape of the active site of the enzyme and the reaction stops -
Why are enzymes specific ?
They are specific so they only fit perfectly wih one substrate, meaning each can only catalyse one reaction
How do different PH values affect the activity of different enzymes ? & why
It caused the H+ or OH- ions to change the forces that hold the active site in its specific shape
This then prevents the substrate from bonding with it, which slows down the reaction until the enzyme is eventually denatured
Examples of where enzymes can be used in the home and in industry ?
Baby foods
Sugar syrup
Fructose syrup
Biological detergents
Why do biological detergents work better than non biological detergents at removing protein and fat stains ?
They use enzymes such as protease and lipase to break down the dirt that stains our clothes, they can be washed away easier making our clothes cleaner
Advantages & disadvantages of biological detergents ?
- work at a low temperature which would otherwise have to be high
- damages the clothes less
- this saves money
- also saved electricity
- people can be allergic
- can’t be used to wash clothes by hand
advantages of enzymes in industry ?
Reactions occur much faster than without enzymes
Reactions can occur at lower temperatures saving money and sometimes reducing damage
Quite cheap to grow microorganisms
Disadvantages of enzymes ?
Can be expensive to extract them
Conditions have to be controlled to optimise enzyme activity which can be expensive
List the digestive enzymes and the organs which produce them
Amylase : salivary glands, pancreas, small intestine
Protease : stomach, pancreas
Lipase : pancreas, small intestine
Bile : liver
How does protease break down proteins ?
Protease - protein - amino acids
How does amylase break down starch?
Amylase - starch - sugars
How are lipids (fats and oils)broken down by lipases?
Lipids - lipase ; fatty acids and glycerol
Differences between aerobic and anaerobic respiration ?
- oxygen is used in aerobic
- more energy from aerobic
- carbon dioxide & water are end products of aerobic
- lactic acid is the end product of anaerobic
What 3 things identify someone as being fitter than another ?
- lower resting heart rate
- quicker recovery time
- lower increase in heart rate
Differences between aerobic and anaerobic respiration ?
- oxygen is used in aerobic
- more energy from aerobic
- carbon dioxide & water are end products of aerobic
- lactic acid is the end product of anaerobic
What 3 things identify someone as being fitter than another ?
- lower resting heart rate
- quicker recovery time
- lower increase in heart rate
Name the product of protein digestion?
Amino acids
What is the name of the acid made by the stomach?
Hydrochloric acid
Name the product of protein digestion?
Amino acids
What type of enzyme digests protein?
Protease
Name the acid made by the stomach which allows pepsin to work well?
Hydrochloride acid
Why give a plant ions?
Plants are provided with the correct nutrients
Why do plants need magnesium ions for healthy growth?
To make chlorophyll which traps light for photosynthesis
Describe the process of breaking down fat molecules?
Occurs in the small intestine
Lipase is produced by the pancreas and small intestine to do this:
Fats —- fatty acids and glycerol
The liver produced bile to neutralise conditions in the stomach and produce alkaline conditions in the intestine
Products are small molecules absorbed by small intestine
What does amylase speed up the digestion of?
Starch to produce sugars
Why do molecules of starch protein and fat need to be digested?
Large and insoluble
Describe the roles of the pancreas and the liver in the digestion of fats?
Pancreas produces lipase
Which breaks down dats into fatty acids + glycerol
Liver produced vile
Which neutralised acids
Provides most effective pH for lipase
Bile emulsified fats
Increasing the surface area for lipase to work on
Why carry out an experiment involving enzymes at 40 degrees?
Optimum temperature for enzyme activity
Any higher would denature the enzyme
Explain why fructose instead of glucose is used in slimming foods?
Fructose is sweeter
So less is needed
Name the enzyme that turns glucose into fructose?
Isomerase
What enzyme turns starch into glucose?
Carbohydrase
Explain how bile affects the digestion of food in the small intestine?
Neutralised acid
Enzymes work more effectively
Emulsified fats to give them a larger surface area
What happens to food containing protein after it had been swallowed?
Digested by protease enzyme from stomach/pancreas
In small intestine
Into amino acids (which are smaller molecules that can be absorbed into the blood)
Name the site of production of bile?
Liver
Name the sites of production of amylase?
Mouth
Salivary gland
Small intestine
Pancreas
Name the site of production of lipase?
Pancreas
Name the sites of production of protease?
Stomach
Small intestine
Pancreas
Describe how the liver helps to digest fats?
Produces bile
Emulsified fat
What are protein molecules made up of?
Long chains of amino acids
Describe the functions of proteins?
Antibodies
Catalysts
Hormones
Structural components of tissues (eh muscles)
What is the shape of protein?
Long chains are folded into a specific shape that enables other molecules to fit into the protein
Describe the function of digestive enzymes?
Pass out of the cells into the gut
Where they come into contact with food molecules
They catalyse the breakdown of large molecules into smaller molecules
Where are digestive enzymes produced?
By specialised cells in glands and in the lining of the gut
Where is amylase produced?
Salivary glands
Pancreas
Small intestine
What does protease do?
It catalysed the breakdown of starch into sugars in the mouth and small intestine
Where are protease enzymes produced?
Small intestine
Pancreas
Stomach
What do protease enzymes do?
Catalyse the breakdown of proteins into amino acids in the stomach and small intestine
Where are lipase enzymes produced?
Pancreas
Small intestine
What do lipase enzymes do?
They catalyse the breakdown of lipids (fats and oils) into fatty acids and glycerol
In the small intestine
What does the stomach produce?
Hydrochloric acid
Why is Hydrochloric acid produced stomach?
The enzymes in the stomach work more effectively in these acid conditions
Where is vile stored?
In the gall bladder
Where is bile produced?
In the liver
What happens after the bile is produced by the liver?
Stored in the gall bladder
Released into the small intestine
What does bile do?
Neutralised the acid that was added to food in the stomach
Providing alkaline conditions in which enzymes in the small intestine work most effectively
What may biological detergents contain?
Proteases
Lipase
In industry why are carbohydrades used?
To convert starch into sugar syrup
Describe the function of Isomerase?
Used to convert glucose syrup into fructose syrup
Which is much sweeter and therefore can be used in smaller quantities in slimming foods
Disadvantages of enzymes in industry?
Denatured at high temperatures
Costly to produce
What are enzymes?
Large protein molecules that act as biological catalysts
Example of changing certain molecules into others?
Glucose to fructose
What happens once the substrate is in place?
The enzyme and substrate bind together
Describe the process of enzymes?
1) substrate fits into the active site of the enzyme (like a lock and key) and bind together
2) the substrate splits into products which leave the active site and are released from the surface of the enzyme
What main two things do enzymes do?
Enzymes can join small molecules together
As well as break up large ones
What happens if milk is left for a week or two?
The enzyme in bacteria will break down the protein structure
Describe the denaturing of enzymes?
The long amino acid chains begin to unravel
The shape of the active site is changed
The enzyme is denatured
How does pH chain enzyme action?
The forces which hold the folded chains of the enzyme in its shape are effected by pH
Therefore the active site is lost so the enzyme no longer acts as a catalyst
Why is it dangerous to have too high a temperature?
Without enzymes nothing in the body would happen fast enough to keep you alive
Thus if enzymes are denatured you will soon die
What does the shape of the active site come from?
The forces between the different parts of the protein molecules
What controlle the chemical breakdown of food?
Enzymes
Where do most enzymes work?
Inside the cells of the body
Where do digestive enzymes work?
They work outside the cells
They are produced by specialised cells in glands
And in the lining of your gut
What is the gut?
A hollow muscular tube that squeezes your food
How is food moved in the gut?
Muscles
Once enzymes in digestion have been produced by specialised cells in glands, what happens?
The enzymes pass out of these cells into the gut itself
Food is broken into small pieces at large surface area for enzymes to work on
It mixes food with digestive kicked so that enzymes come into contact with as much of the food as possible
What is one of the most common carbohydrates?
Starch
Where is starch broken down?
Mouth and small intestine
What catalysed the breakdown of carbohydrates?
The enzyme of amylase
What are carbohydrases broken down into?
Sugars
Where is amylase produced?
Salivary glands
Pancreas
Small intestine
What does not happen in the pancreas?
No digestion
Where is most of the starch digested?
In the small intestine
What foods are broken down with the catalyst of protease enzymes?
Protein foods like meat dish and cheese
Where does the breakdown of proteins take place?
In the stomach and small intestine
What are lipids?
Fats and oils
Where are lipase enzymes made?
In the pancreas and pass into the small intestine
Examples of soluble food molecules?
Glucose
Amino acids
Fatty acids and glycerol
What happens once food molecules have been completely digested?
They leave the small intestine
They pass into the bloodstream
To be carried around the body to the cells which need them
What condition does protease (found in the stomach) to work best?
Acidic conditions
What conditions do protease (made in the pancreas) need to work best?
Alkaline conditions
Roughly how many glands are there in the lining of the stomach?
35 million glands
Why does the stomach produce Hydrochloric acid?
Protease enzymes work best in acidic conditions
Kills most of the bacteria that you take in with your food
Why does the stomach have a thick layer of mucus?
This coats your stomach walls and protects them from being digested by the acid and the enzymes
What adaptations does the stomach have for digestion?
Mucus which coats the stomach walls
Released Hydrochloric acid
What colour is bile?
Greenish yellow
Once food has left the stomach where does it go?
Small intestine,
Some of the enzyme involved in this later stage are produced in the small intestine and some in the pancreas
How does the acidic liquid coming from the stomach become alkaline?
The liver makes an alkaline liquid called bile
As food comes into the small intestine from the stomach, bile is squirted onto it
The bile neutralised the acid from the stomach and then makes the semi digested food alkaline
Making the ideal conditions needed for the enzymes in the small intestine
What is the secondary function of bile?
It emulsified the cats in your food
This means bile physically breaks up large drops of day into smaller droplets
This provides a much bigger surface area for the lipase enzymes to act on
The larger the surface area helps the lipase chemically break down the fats more quickly into fatty acids and glycerol
What does bile do?
EMULSIFIES
bile is not an ENZYME
Where is food NOT digested?
Liver
Pancreas
Why do fats need bile?
They need to be emulsified
As fats that are eaten do not mix with watery liquids in the gut
They stay as large ‘globules’ that make it difficult for the lipase enzymes to act
What can biological detergents be used for?
Remixing stains such as grass, sweat and food
Enzymes break down the proteins and fats in stains
What temperature do biological detergents need?
Lower temperatures because enzymes work best a lower temperature
Less electricity is used
Why are professes used to make baby foods?
They ‘predigest’ some of the protein in the food
Tearing the food with protease enzymes make it easier for a baby’s digestive system to cope with
It is easier for them to get the amino acids they need from their food
What are carbohydrases used for?
Converting starch into sugar
What is starch used for in industry?
Starch is made by plants like corn and is very cheap
Using enzymes to convert this plant starch into sweet sugar provides a cheap source of sweetness for food manufacturers
It is also an important process for making fuel from plants
What is the glucose syrup from plants used for?
Made from starch, the glucose syrup is turned into fructose syrup by the enzyme Isomerase
Why convert glucose to fructose?
Much smaller amounts are needed to make food taste sweet
Fructose are used in slimming foods
The food tastes sweet which contains fewer calories
What do most enzymes end in?
Ase
How are enzymes used to diagnose disease?
If the liver is damaged or diseased
Some liver enzymes may leak out into the bloodstream
Doctors can test blood for these enzymes
This will tell them if the liver is really damaged
How are enzymes used to diagnose and control disease?
Too much glucose in their blood (diabetes)
So they have glucose in urine
There can be tested for using a colour change on a test strip containing an chemical enzyme
It is placed in a urine sample
The enzyme catalysts the breakdown of glucose found in the grime
The strip changes colour of the products of the reaction are present
Showing if glucose was in the original sample
Properties of protease?
Produced in stomah, pancreas and small intestine
Catalysed the breakdown of PROTEINS into AMINO ACIDS in the stomach and small intestine
Properties of lipase?
Produced by pancreas and small intestine
Catalysts the breakdown of LIPIDS into FATTY ACIDS AND GLYCEROL in the small intestine
Properties of amylase?
Produced in SALIVARY GLANDS PANCREAS AND SMALL INTESTINE
Catalysts breakdown of STARCH into SUGARS in the mouth and small intestine
What happens in the large intestine?
Excess water is absorbed from food
What happens in the stomach?
Churns food with muscular walls
Produces protease enzymes
Produced Hydrochloric acid (protease needs an acidic pH, kills bacteria)
What happens in the pancreas?
Produces protease, amylase and lipase
It releases these into the small intestine
What happens in the small intestine?
Produces protease amylase and lipase
To complete digestion
Digested food is absorbed out of the digestive system Ito the blood
Where is glycogen stored?
In they liver
