Enzymes Flashcards
State the definition of enzyme
A protein that acts as a biological catalyst to speed up chemical reactions
At what temperature do enzymes work best?
Optimum temperature
What is the optimum temperature of the human body?
37 degrees celsius
What happens to the enzyme if it is in high temperatures?
The bonds that hold together the enzyme break causing the 3D shape to become deformed - become denatured. This means the substrate cannot fit into denatured enzymes as the active site has lost its complementary shape
What is a substrate?
A molecule which binds onto the active site
What does complementary mean?
In the case of enzymes, only one substrate can fit into one particular active site. Specific to only one active site
What is the active site?
A part of the enzyme where the substrate binds
How does increasing temperature affect the rate enzymes work at?
Increasing the temperature increases the activity of enzymes as there is more kinetic energy meaning the enzymes will move faster causing more successful collisions with the substrate molecules
What happens to the enzyme if it is in low temperatures?
The rate of enzyme activity slows down
How does pH affect enzyme activity?
If the pH is too high or too low than the enzyme could denature causing the substrate to be unable to fit into the active site
What is denaturation?
When the 3D shape of the active site changes shape meaning that the substrate is unable to fit in with the lock and key method
Where is salivary amylase produced?
Salivary glands
What does salivary amylase break down and produce?
Starch into Maltose
Where is protease produced?
Stomach and Pancreas
What does protease break down and produce?
Protein into amino acids
Where is lipase produced?
Pancreas
What does lipase break down and produce?
Lipids into fatty acids and glycerol
Where is pancreatic amylase produced?
Pancreas
What does pancreatic amylase break down and produce?
Starch into maltose
Where is maltase produced?
Small Intestine
What does maltase break down and produce?
Maltose into glucose
Where does lipase work?
Small Intestine
Where does protease work?
Stomach and Small Intestine
Where does amylase work?
Mouth and Small Intestine
Where does maltase work?
Small Intestine
What is vitamin A needed for and where is it produced?
Vision (especially night vision) and produced in carrots
What is an effect of a deficiency of vitamin A?
Blindness
What is vitamin C needed for and where is it produced?
Forms protein for hair, skin, gums and bones, and produced in citrus fruit
What is an effect of a deficiency of vitamin C?
Scurvy
What is vitamin D needed for and where is it produced?
Absorbs calcium for strong bones and teeth and produced in oily fish
What is an effect of a deficiency of vitamin D?
Rickets
What is calcium needed for and where is it produced?
Strong teeth and bones, involved in blood clotting, and produced in milk
What is an effect of a deficiency of calcium?
Weak bones
What is iron needed for and where is it produced?
To make haemoglobin and produced in red meat
What is an effect of a deficiency of iron?
Anaemia
How does energy content vary depending on age?
As children age the energy content increases as they need energy for growth. As adults age energy content decreases
How does energy content vary depending on the person’s activity levels?
The more active a person is, the more energy that is required because muscles are contracting more meaning the respiration rate is faster
How does energy content vary depending on pregnancy?
Energy content increases because energy is needed to support the growth of the developing fetus
State the definition of the digestive system.
The bodily system concerned with the ingestion, digestion, and absorption of food
What is the function of the mouth in the digestive system?
Mechanical digestion takes place in the mouth and amylase enzymes digest starch into maltose
What is the function of the oesophagus in the digestive system?
The tube that connects the mouth to the stomach - where food goes after entering the mouth and being mechanically digested
What is the function of the stomach in the digestive system?
Food is mechanically digested and protease enzymes chemically digest proteins. HCl is present to kill bacteria
What is the function of the small intestine in the digestive system?
Where the food comes out of the stomach and finishes being digested by enzymes produced in the small intestine
What is the function of the large intestine in the digestive system?
Water is absorbed and faeces are removed from the body through the anus
What is the function of the pancreas in the digestive system?
Produces amylase, protease and lipase enzymes. Secretes enzymes for digestion into the small intestine
What is peristalsis?
The contraction of two sets of muscles in the wall of the gut
What is the purpose of digestion?
To break down large, insoluble molecules (carbohydrates, proteins and lipids) into small, soluble molecules that can be absorbed into the bloodstream
What does the liver produce?
Bile
Where is bile stored?
The gall bladder
What are the two main roles of bile?
To neutralise the hydrochloric acid from the stomach and to emulsify lipids (break down large insoluble molecules into smaller soluble molecules)
State the definition of absorption
The movement of digested food molecules from the digestive system into the blood
How is the ileum adapted for absorption?
Very long and has millions of villi which create a larger surface area which allows absorption to take place faster
What are the adaptations of the villi?
1) Microvilli which increase surface area, therefore increasing the rate of absorption
2) One cell thick wall which means there is a short diffusion pathway
3) Blood capillary network which transports glucose and amino acids away from the small intestine
What is the test for glucose?
1) Add Benedict’s solution to the sample solution
2) Heat in a 60-70 degrees Celsius water bath
3) If glucose is present in the sample solution then the colour would change from blue to brick red
What is the test for starch?
1) Add a few drops of Iodine to the sample solution
2) If starch is present the colour would change from brown to blue-black
What is the test for protein?
1) Add a few drops of Biuret solution to the sample solution
2) If protein is present the colour would change from blue to purple
What is the test for lipids?
1) Mix the food sample with ethanol
2) If a lipid is present then the solution would become cloudy
What is the lock and key hypothesis?
Enzymes are specific to one particular substrate as the active site of the enzyme, where the substrate attaches, is a complementary shape to the substrate
