B3 - Organisation and The Digestive System Flashcards
What is a tissue?
A group of cells with similar function, working together
What is an organ?
A collection of tissues working together to perform a specific function
How is an organ, a tissue?
The tissues all work together to perform a specific function
What does food provide?
Energy
What are the three types of carbohydrates?
Sugar
Fibre
Starch
What type of energy do sugary foods release? (Fizzy drinks, Chocolate)
Fast release of energy
What does Fibre do?
Adds bulk to the food to prevent constipation
What type of energy does starchy food release? (Bread, potatoes, rice)
Slow release of energy
Why do starchy foods take longer to release energy than sugary foods?
Starchy foods have longer carbohydrate chains so it takes longer to break down
What is the structure of a Lipid?
Three molecules of fatty acids, joined to a molecule of glycerol
What are carbohydrates made up of?
Units of sugars
What are carbohydrates broken down into?
Glucose
What are Carbohydrates and Lipids chemically made up of?
Carbon, Hydrogen and Oxygen
What are Protiens chemically made up of?
Carbon, Hydrogen, Oxygen and Nitrogen
What are Protiens made up of?
Long chains of animo acids joined together
Where does most digestion take place?
Small intestine
Which indicator do you use when testing for Sugar?
Benedicts solution
Which indicator do you use when testing for Starch?
Iodine
Which indicator do you use when testing for Protien?
Biuret reagant
Which indicator do you use when testing for Lipids?
Ethanol (Sudan III)
What does a positive result look like when testing for sugar?
Blue benedicts solution will turn BRICK RED 🧱🔴
What does a positive result look like when testing for Starch
Turns red iodine into BLUE-BLACK🔵⚫️
What does a positive result look like when testing for Protien?
Blue Biuret turns PURPLE 🟣
What does a positive result look like when testing for Lipids?
When Ethanol is added, the solution gives a CLOUDY-WHITE 🌫️ layer
What is the name of the chemicals found in food?
Nutrients
What are carbohydrates made up of?
Long chains of simple sugars like glucose
Which enzymes digest carbohydrates
Carbohydrase enzymes
What is the function of protien in the diet?
For growth and repair of body tissues
Where is protien digested?
Small intestine and stomach
What is the name of the enzyme that digests protiens
Protease
What is the fuctions of fats in the diet?
Store of energy and provides insulation
Where are fats digested?
The small intestine
What is the name of the enzyme that breaks down fats
Lipase
Which enzyme breaks down Starch?
Amylase
Starch is broken down by Amylase, into _______ ______ _______
Smaller sugars called maltose
Where is amylase produced?
Salivary glands
pancreas
small intestine
protiens are broken down by protease, into _____ _____
Amino Acids
Where is protease produced?
Stomach (pepsin)
pancreas
Small intestine
Fats (Lipids) are broken down by Lipase, into ________ and _____ _____
Glycerol and Fatty Acids
Where is lipase produced?
Pancreas
Small intestine
Why does bread sweeten when chewed for a long period of time?
Bread contains starch
Starch is broken down by amylase to produce simple sugars
Amylase is found in the salivary glands so thats why you can taste it
What is a catalyst?
A substance that increases the rate of a chemical reaction
Why is it called The Lock and Key Theory?
The substrate fits perfectly into the active site of the enzyme
What happens after the substrate fits into the active site?
The substrate splits into products which leave the active site so the enzyme can be used again
What is Metabolism?
The sum of all the reactions in a cell or body
What are enzymes made up of?
Protiens
What is meant by the ‘Optimum’ Temperature?
The ideal temperature for the fastest enzyme reactions
What happens to an ezyme after it goes beyond optimum temperature?
The enzyme and its active site starts to denature and change shape
Why is it a problem for enzymes to denature past the optimum temperature?
The substate cant combine with the enzyme so no reaction can take place
What does pH mean?
Potential of Hydrogen
What does a low pH mean?
Conditions are acidic
What does a high pH mean?
Conditions are alkaline
Why does enzyme activity decrease when it is not at its optimum pH
Its denatures because the pH has an effect on the enzymes forces which leads to change of shape
Why is it difficult for lipase enzymes to act on fats
They dont mix well with lots of watery liquids
What is bile?
An green-yellow alkaline liquid which neutralises acidic liquid from your stomcach
Where is bile made?
The liver
Where is bile stored?
The gall bladder
What acid does the stomach produce?
Hydrochloric Acid
Digestion is the process of breaking down large food molecules into smaller molecules that are ________
Soluble
Enzymes help break down food because they __________ chemical reactions
Catalyse
Describe how you would test a food sample to show it contains Protein
Give the reason for any safety precautions you would take.
-Prepare food sample by grinding it with a pestle a motar
-Place that into a clean test tube
-Add a few drops of biuret reagant and leave for 10 minutes
-if sample turns blue biuret reagant to purple 🟣, protien is present
-Biuret is an irritant so you must wear goggles and if it comes inti contact with skin, rinse immediately
Describe how you would test a food sample to show it contains STARCH.
Give the reason for any safety precautions you would take.
-Prepare food sample by grinding it with a pestle a motar
-Place that into a clean test tube
-Add a few drops of iodine solution and leave for 10 minutes
-if sample turns red iodine solutions to Blue-Black🔵⚫️, starch is present
-iodine is an irritant so you must wear goggles and if it comes into contact with skin, rinse immediately
What does the muscular tissue do?
Contract
What does the glandular tissue do?
Makes and secretes chemicals like enzymes and hormones
What does the epitherlial tissue do?
Covers some parts of the body like inside the gut
How do you investigate how pH affects amylase activity?
Add a drop of iodine into every spotting tile
Add a pH 5 buffer solution to the amylase test tube in 35°C water
Wait 5 minutes to then add starch solution to the test tube
Add the mixture to the iodine solution every 30 seconds
If iodine solution remains orange, starch is no longer present
Repeat with different pH buffer solutions
The bile ‘emulifies’ fats.
What does this mean?
It breaks down the fats into tiny droplets
What does the stomach do?
Churns the food with ite muscular walls
Produces the protease enzyme, pepsin
Produces hydrochloric acid
Why does the stomach produce hydrochloric acid?
To kill bacteria
To give right pH for pepsin to work
What pH is hydrochloric acid?
pH 2
What does the small intestine do?
Produces protease, amylase and lipase enzymes to complete digestion
Absorbs the food into the blood stream
What does the large intestine do?
Absorbs the excess water from undigested food
Turns food into faeces
Explain how amylase breaks down starch.
Answer in terms of the ‘lock and key theory’
Thr substrate (starch) fits perfectly into the active site of the amylase enzyme
Checmial reaction occurs to produce products (maltose which are smaller sugars)
