Topic 2 - Organisation Flashcards
What is a cell?
Cells are the basic building blocks that make up all living organisms.
What is an example of a cell in plants?
Root hair cell.
What is an example of a cell in animals?
Epithelial tissue.
What is a tissue?
A tissue is a group of similar cells that work together to carry out a particular function.
What is an example of a tissue in animals?
Epithelial tissue covers some parts of the body.
Muscular tissue contracts to move whatever its attached to.
Glandular tissue which makes and secretes chemicals like enzymes and hormones.
What is an organ?
An organ is a group of different tissues that work together to perform a particular function.
What is an example of an organ?
The stomach which is made out of muscular tissue, glandular tissue and epithelial tissue.
Muscular tissue moves the stomach to churn up the food.
Glandular tissue which makes digestive juices to digest food.
Epithelial tissue which covers the outside and inside of the stomach.
What is an organ system?
It is a group of organs working together to perform a particular function.
Give an example of an organ system.
The digestive system breaks down and absorbs food. It is made up of; Salivary Glands Pancreas Stomach Small intestine Large intestine Liver
What is the role of each organ in the difestive system?
Pancreas and Salivary Gland-Produces digestive juices
Stomach and Small Intestine-Digests food
Liver-Produces bile
Small Intestine-Absorbs soluble food molecules
Large Intestine-Absorbs water from undigested food
What is a catalyst?
A substance that increases the speed of a reaction without being changed or used up in the reaction.
How do enzymes work?
Every enzyme has an active site with a unique shape that fits onto the substance involved in the reaction.
The substrate complimentary to the enzyme collides creating an enzyme substrate complex.
The substrate breaks down in the active site.
The product is then released so the enzyme can be reused.
How does temprature effect enzymes?
At first the higher temprature increases the rate.
But then when the enzyme passes optimum temprature the bonds holding the enzyme together begins to break which denatures the enzyme.
This means the substrate wont fit into the active site anymore.
How does pH effect enzymes?
If it is too high or too low it changes the shape of the active site and it denatures.
Explain how you investigate how pH effecrs amylase activity.
Put a bunsen burner on a heat proof mat and s tripod and gauze over it. Put a beaker of water over it and heat the water until it is 35 degrees.
Use a syringe and add 1cm cubed of amylase soultion and 1cm cubed of buffer solution with pH 5 to a boiling tube.
Using test tube holders, put the tube into the beaker of water and wait five minutes.
Then add 5cm cubed of starch solution to the boiling tube.
Mix the contents and start a stop clock.
Use continuous sampling and record how long it takes for the amylase to break down the starch.
Take a fresh sample from the boiling tube every 30 seconds and put a drop into a well.
When the iodine solution remains browny orange starch is no longer present.
Repeat the experiment wirh different pH values and see how it effexts the time for starch to be broken down.
How do you calculate the rate of reaction?
Rate = 1000
———
Time
Where is amylase found?
Salivary Glands
Pancreas
Small Intestine
Where is protease found?
Stomach
Pancreas
Small Intestine
Where is lipase found?
Pancreas
Small Intestine
What is the role of bile in the digestive system?
The stomach makes the pH to acidic for the enzymes in the small intestine so bile neutralises the acid because it is an alkaline.
It emulsifies fats which gives a much bigger surface area for lipase meaning faster digestion.
What is the role of hydrochloric acid in the digestive system?
To kill bacteria.
To give the right pH for protease to work.
How do you test for sugars in foods?
Prepare a food sample and put 5cm cubed into a test tube.
Prepare a water bath and set it to 75 degrees.
Add Benedict’s solution (about 10 drops)
Put the test tube into the water bath and leave it there for five minutes.
If the food sample contains a sugar it will go from blue to green, yellow or brick-red depending on how much sugar.
How do you test for starch in food?
Put 5cm cubed of food sample into a test tube.
Add a few drops of iodine solution abd gently shake in the tube.
If the contents contains starch the colour will change from browny-orange to black or dark blue.
How do you test for proteins in food?
Prepare a food sample and put 2cm cubed of your sample in a test tube.
Add 2cm cubed of biuret solution to the sample and mix by gently shaking it.
If it contains protein it should change from blue to pink or purple.