2. Organisation Flashcards
What is the cardiovascular system an example of?
An organ system.
In plants, what are leaves examples of?
Organs.
What is the definition of an organ?
A group of different tissues working together to perform a common function.
What is a tissue?
A tissue is a group of cells with similar structure and function working together.
What does a catalyst do?
Catalysts increase the rate of chemical reactions without changing chemically themselves.
What is an enzyme?
Enzymes are large protein molecules. They are made up of chains on amino acids folded together to make large complex models.
What is the active site of an enzyme?
Amino acids chains are folded to form the active site, which matches the shape of a specific substrate molecule.
Explain how enzymes act to speed up reactions in your body.
The substrate binds to the active site and the reaction is catalysed by the enzyme.
What is metabolism?
Metabolism is the sum of all reactions in a cell or in a body.
How can a high temperature affect the nature of an enzyme?
High temperatures can denature the enzyme, changing the shape of the active site.
How can pH affect the nature of an enzyme?
pH can affect the shape of the active site of an enzyme and make it work very efficiently or stop it working.
What are the three types of
catalyst enzymes found in the body?
Amylase, protease and lipase.
What are digestive enzymes produced by?
Digestive enzymes are produced by specialised cells in glands and in the lining of the digestive system.
What do proteases breakdown?
Proteases catalyse the the breakdown of proteins to amino acids.
What do lipases breakdown?
Lipases catalyse the breakdown of lipids to fatty acids.
What are the enzymes that break down carbohydrates?
Carbohydrases.
What enzyme is the break down of proteins into amino acids catalysed by?
Protease.
Where in the body does the break down of proteins into amino acids take place?
The stomach and small intestine.
What are lipids broken down into and where in the body does this take place?
Lipids are broken down into fatty acids and glycerol in the small intestine.
What is the enzyme that catalyses the reaction where lipids are broken down called?
Lipase, which are made in the small intestine.
What happens once all of the food molecules have been digested completely?
They leave your small intestine and flow into your bloodstream to be carried to the cells that need them.
Explain why amylase, starch and iodine are used in investigating the affect of pH on the rate of reaction of amylase.
Iodine forms a blue/black complex when starch is present, but does not react with glucose. In this investigation a blue/black solution of starch and iodine will change to brown as the enzyme amylase digests/breaks down the starch into sugar. The time taken for this reaction to occur is affected by temperature.
Is bile an enzyme?
No
What are examples of protease enzymes?
Trypsin and pepsin
How does bile help with the digestion of lipids?
It emulsifies the lipids which increases the surface area for lipase enzymes to break them down.
The digestive system has two main roles. Briefly describe each of them.
Digestion - process of breaking down large food molecules into smaller molecules
Absorption - process of absorbing these small food molecules into the body
When we chew food, our teeth physically break the food down into smaller pieces. How does this help?
It increases the surface area for enzymes to act on.
It make the food easier to swallow.
What is the official name for the tube that carries food from the mouth to the stomach?
Oesophagus
What are the three main roles of the stomach?
- The stomach contracts its muscular walls to churn and mix the food.
- It produces pepsin, which is a type of protease enzyme, and breaks proteins down into amino acids.
- It produces hydrochloric acid, which a) provides the right pH for pepsin to function, and b) kills microorganisms.
What are the three main roles of the stomach?
- The stomach contracts its muscular walls to churn and mix the food.
- It produces pepsin, which is a type of protease enzyme, and breaks proteins down into amino acids.
- It produces hydrochloric acid, which a) provides the right pH for pepsin to function, and b) kills microorganisms.
What are the main roles of bile?
Bile is made by the liver, but it is stored in the gallbladder,
After we have meal, it is released into the small intestine where it helps in two ways:
1. One is to emulsify lipids, which means separate large droplets of lipid into smaller droplets.
2. The other is to neutralise the acid from the stomach, which bile can do because it is alkaline.
Which enzymes does the pancreas produce?
Amylase, proteases, and lipases
Which enzymes does the small intestine produce?
Amylase, proteases, and lipases
What is the main role of the large intestine?
Absorb water
Which test is used to detect the presence of reducing sugars (i.e. small sugars like glucose)?
Benedict’s test
Does the Benedict’s test require heating the sample in a water bath?
Yes
What does iodine test for?
Starch
Iodine solution is used to test for the presence of starch. If starch is present, which colour change takes place?
Orange to blue/black