B3-Organisation And Digestive System Flashcards
(88 cards)
1
Q
What do cells do to become specialised cells?
A
Differentiate
2
Q
What are the levels of organisation?
A
Cells->Tissue->Organ->Organ System-> Organism
3
Q
What is tissue?
A
Tissue is a group of cells with similar structure. They function and work together. For example, muscular tissue contracts to bring movement.
4
Q
What is an organ?
A
an aggregation (collection ) of different tissues working together to carry out specific functions
5
Q
What is an organ system?
A
a group of organs that work together to carry out specific functions
6
Q
Give an example of a specialised cell
A
Sperm Cell
7
Q
give an example of a type of tissue
A
Muscular Tissue
8
Q
give an example of an organ
A
Stomach
9
Q
give an example of an organ system
A
Digestive System
10
Q
What is emulsification?
A
Emulsification is the process of bile breaking large fatty globules into smaller fatty globules to increase the surface area the lipids to make it easier for for lipase to break down the lipids.
11
Q
What is neutralisation?
A
In your stomach there is a protease enzyme called pepsin. Pepsin works best in an acidic PH, so your stomach produces hydrochloric acid to provide this environment. Your Stomach has a layer of mucus to protect its self against this acid. In your small intestine the enzymes work best in an alkaline PH rather than acidic. When the acidic mixture moves into your small intestines an alkaline fluid called bile neutralises the acid, this lets the enzyme work more efficiently
12
Q
What is carbohydrase?
A
enzymes that speed up the breakdown of carbohydrates into simple sugars
13
Q
What are carbohydrates?
A
molecules that contain only carbon, hydrogen, and oxygen. They provide the energy for the metabolism and are found in foods such as rice, potatoes, and bread
14
Q
What is a catalyst?
A
a substance that speeds up the rate of another reaction but is not used up or changed itself
15
Q
What is a denatured Enzyme?
A
When an an enzyme’s molecular structure is broken down so it no longer functions
16
Q
What is the digestive system?
A
organ system where food is digested and absorbed
17
Q
What are enzymes?
A
biological catalysts, usually proteins
18
Q
What are fatty acids?
A
part of the structure of a lipid molecule (Triglyceride)
19
Q
What is glycerol?
A
part of the structure of a lipid molecule (Triglyceride)
20
Q
What is lipase?
A
enzymes that speed up the breakdown of lipids into fatty acids and glycerol
21
Q
What are lipids?
A
Molecules made of carbon, hydrogen and oxygen. They are found in fats and oils.
22
Q
What is the metabolism?
A
the sum of all the reactions taking place in a cell or the body of an organism
23
Q
What is protease?
A
enzymes that speed up the breakdown of proteins into amino acids
24
Q
What are proteins?
A
molecules that contain carbon, hydrogen, oxygen, and nitrogen and are made of long chains of amino acids. They are used for building the cells and tissues of the body and to form enzymes
25
What are simple sugars?
small carbohydrate units, for example glucose
26
Where is bile stored and produced?
Bile is stored in the gallbladder and produced in the liver
27
How is the small intestine adapted to absorb food efficiently?
The small intestine has villi and microvilli which increase the surface area for absorption, allowing more nutrients to be absorbed quickly.
Each villus has thin walls that are only one cell thick, reducing the distance nutrients must travel to enter the blood.
A rich blood supply surrounds the villi, carrying nutrients away and maintaining a steep concentration gradient for efficient diffusion.
28
How does an enzyme work?
Enzymes contain a very specifically shaped active site, this shape is complementary to the shape of 1 specific substrate. The enzyme and substrate bind together (like a lock and key) to form an enzyme substrate complex. The enzyme then catalysers the breakdown of the substrate into the products. It would not catalyse the breakdown of another substrate as the enzymes active site is only a specific shape to 1 substrate. The enzyme is not used up or changed in any way during this process
29
Describe the process of food moving through the digestive system
Food starts in the mouth, it is ground up into small pieces by your teeth. A carbohydrase enzyme called amylase is produced by the salivary glands and breaks down starch into simple sugars. The oesophagus then pushed the food down into the stomach. Food enters the stomach through a ring called the sphincter. Food is mixed with hydrochloric acid so that pepsin has the correct PH conditions to work in. The stomach strong muscular walls to churn the food. Food then moves through to your small intestine. As food enters your small intestine bile is squirted onto the mixture to perform neutralisation and emulsification. In the small intestine many enzymes help digest food. The food is then squeezed into the large intestine where water is absorbed. The faeces then moves into your rectum and eventually out your anus.
30
Where is protease produced?
In the stomach, In the small intestine,pancreas
31
Where is lipase produced?
Small intestine,pancreas
32
Where is carbohydrase produced
Salivary glands,pancreas,small intestine
33
Where is carbohydrase found
Mouth,small intestine
34
Where is protease found
Stomach,small intestine
35
Where is lipase found
Small intestine
36
What enzyme breaks Hydrogen Peroxide into Water+Oxygen and where is it found?
Catalase found in the liver
37
What are carbohydrates made of?
Simple sugars such as Glucose
38
What do carbohydrates do?
Breaks down starch into simple sugars. are our main source of energy
39
What are proteins made of?
amino acids
40
What do lipids do?
Lipids are the most efficient energy store in your body
41
What colour Iodine Solution turn when there is a positive result for starch?
From yellow-red to blue-black
42
What do proteins do?
Proteins are used for the building up of cells and tissue in your body. They are also used to make Enzymes, Hormones and Antibodies
43
What effect does temperature have on the rate of an enzyme controlled reaction?
As temperature increases enzyme activity increases until peaking at around 37~C. After 40~C the enzyme activity starts to decrease rapidly before completely stopping at around 55~C. This is because as temperature increases the enzymes and substrate gain more kinetic energy and have more collisions with each other. At around 40~C is the optimum temperature for Enzyme-substrate collisions. After 40~C the active site of the enzyme begins to change shape and therefore none of the collisions will be successful. After around 40~C the enzyme has become denatured and stops working.
44
What is the effect of PH on an amylase reaction?
The rate of an amylase reaction increases with increasing PH until peaking at around a PH of 7 with a rate of 14.3. After a PH of 7 the rate of an amylase reaction starts to decrease towards a rate of 3.3 at a PH of 8 . This is because the shape of an enzymes active site comes from the forces between different parts of the protein molecule. When the PH is changed this can affect the forces between the molecule. This can change the shape of the molecule and therefore the active site. This causes the specific shape of the enzyme to be lost and for the enzyme to become denatured.
45
Required practical:Describe the practical experiment of PH on an amylase reaction
1) Use the syringe to place 2cm^3 of amylase solution into a test tube2) Use another syringe to add 1cm^3 of PH Buffer solution to the test tube3) Place the test tube into a water bath set at 30~C and leave for 5 minutes4) Whilst waiting add a drop of iodine solution into each dimple of a spotting tile5) After 5 minutes, use another syringe to add 2cm^3 of starch to the solution, start the stop clock. Mix using a plastic pipette 6) Remove 1 drop of the mixture after 10 seconds and add to the first drop of iodine on your spotting tile7) Wait another 10 seconds, the remove a second drop of the mixture to add to the next drop of the iodine8) Repeat step 7 until the iodine solution and the mixture remains orange9) Record the time taken for the amylase to fully digest the starch10) Repeat the whole procedure with a different PH buffer
46
Required practical:Describe how to test for starch
1) Place a small amount of food on the spotting tile2) Add a few drops of iodine solution onto the food3) Iodine solution will turn black-blue if starch is present4) Repeat steps 1-3 for other types of food5) Record all of your results in a results table
47
Required practical:Describe how to test for sugar
1) Place a small amount of food in a test tube2) Add enough Benedicts solution to cover food3) Place the test tube in a warm water bath for 10 minutes4) Benedicts solution will turn from blue to brick red on heating if a sugar is present5) Repeat steps 1-4 for for other types of food6) Record all of your results in a results table
48
Required practical:Describe how to test for lipids
1) Place a small amount of food in a test tube 2) Add a few drops of ethanol3) Shake the test tube and leave for 1 minute4) Pour the solution into a test tube of water5) Ethanol added to the solution should create a cloudy white layer if a lipid is present6) repeat steps 1-5 for other food7) Record all of your results in a results table
49
Required practical:Describe how to test for proteins
1) Place a small amount of food in a test tube
2) Add 1cm^3 of Biuret Solution
3) Biuret Solution will turn purple if a protein is present
4) Repeat steps 1-3 for other foods
5) Record all of your results in a results table
50
What are the 2 formulas for the rate of reaction of an enzyme reaction?
rate of reaction = amount of product formed/time
rate of reaction = amount of reactant used/time
51
How do you take a sample of food for a food test? (must be included in method)
1) Take a piece of food and break it into small pieces using a mortar and pestle
2) Place the broken up food into a beaker of distilled water and stir with a glass rod until most of the substance dissolves
3) Filter the solution into a test tube using a filter funnel and filter paper to remove solid, undissolved chunks of food.
52
What is the name of the chemicals found in food?
Nutrients
53
What are the 3 types of carbohydrate?
Sugar, starch and fibre
54
What is the function of sugar (carbohydrate)?
Gives us energy
55
What is the function of starch (carbohydrate)?
Gives us energy
56
What is the function of fibre (carbohydrate)?
Prevents constipation
57
Name 2 food that contain protein.
Eggs, milk, chicken, beans etc
58
What are fats/lipids made out of?
1 molecule of glycerol and 3 fatty acids
59
Name 2 types of foods that contains fats.
Cream, butter, oils etc
60
What is the name of the specific shape of the enzyme that binds the substrate molecule?
Active site
61
What is the name of the molecule the enzyme breaks down?
Substrate molecule.
62
When the enzyme and substrate molecule combine, what is formed?
An enzyme-substrate complex.
63
What is the formula to calculate the rate of enzyme action.
1/time taken
64
What are cells
Cells are the basic building blocks of all living organisms.
65
What do organs that work together make
Organs are organised into organ systems, which work together to form organisms.
66
Control variables for investigating the effect of pH on the rate of reaction of amylase enzyme
Temperature
Vol of starch,iodine,amylase,buffer solution
Conc of starch,iodine,amylase,buffer solution
67
Source of error in investigating the effect of pH on the rate of reaction of amylase enzyme
How can you improve it?
Difficult to judge exact time when the starch was broken down
Improvements:More pH values,shorter time,take mean
68
What is the ‘lock and key theory’ and how does it explain enzyme action?
Each enzyme has a specifically shaped active site (the "lock").
Only a substrate with the exact complementary shape (the "key") can fit into the active site.
When the substrate binds to the active site, an enzyme-substrate complex forms.
The enzyme then catalyses the reaction, breaking down or building up the substrate.
The products are released, and the enzyme remains unchanged.
69
What does protease do
Breaks down proteins into amino acids
70
What are the simple word equations for the breakdown of food in digestion?
🔹 Starch → sugars
(by amylase)
🔹 Proteins → amino acids
(by protease)
🔹 Lipids → fatty acids + glycerol
(by lipase)
🔹 Bile → emulsifies fats
(not an enzyme, but helps lipase work more effectively)
71
What is amylase and what does it do
Amylase is an enzyme is a carbohydrase which breaks down starch.
72
What does lipase do
break down lipids (fats) to 1 glycerol and 3 fatty acids.
73
What do digestive enzymes do
Digestive enzymes convert food into small soluble molecules that can be absorbed into the bloodstream.
74
What are the products of digestion used for
The products of digestion are used to build new carbohydrates, lipids and proteins. Some glucose is used in respiration.
75
Function of bile
Bile is made in the liver and stored in the gall bladder. It is alkaline to neutralise hydrochloric acid from the stomach. It also emulsifies
fat to form small droplets which increases the surface area. The alkaline conditions and large surface area increase the rate of fat
breakdown by lipase.
76
Organs involved in digestive system
mouth, oesophagus, stomach, liver, pancreas, small intestine, large intestine, rectum.
77
How are enzymes related to metabolism?
Enzymes are biological catalysts that speed up metabolic reactions, such as breaking down large molecules or building new ones.
78
Why are enzymes specific to certain reactions?
Because only substrates with the correct shape fit into the enzyme’s active site – like a key in a lock.
79
What happens to enzymes at low temperatures?
The reaction is slower because molecules have less kinetic energy, so there are fewer collisions between enzymes and substrates.
80
What happens to enzymes at high temperatures?
The enzyme can denature – its active site changes shape, so the substrate can no longer bind, and the enzyme stops working.
81
How does pH affect enzyme activity?
Each enzyme has an optimum pH. Too high or too low a pH can denature the enzyme, changing the shape of the active site so the substrate cannot bind.
82
What is the active site of an enzyme?
The active site is the specially shaped part of the enzyme where the substrate fits and the reaction takes place.
83
What is a substrate in an enzyme reaction?
A substrate is the molecule that fits into the enzyme’s active site and is changed into products by the enzyme.
84
suggest the function of glandular,
epithelial, and muscular tissue in organs.
Glandular Tissue – Produces and releases substances like enzymes, hormones, or mucus. (e.g., in the stomach, it secretes digestive juices.)
Epithelial Tissue – Covers and protects surfaces inside and outside the body. (e.g., in the intestines, it absorbs nutrients.)
Muscular Tissue – Contracts to allow movement. (e.g., in the stomach, it churns food.)
85
explain how enzymes speed up
reactions.
enzymes lower the activation energy, reactions can happen faster and at lower temperatures than they would without the enzyme.
86
explain how enzymes control
metabolism
Enzymes control metabolism by speeding up chemical reactions in the body. Metabolism includes all the reactions that occur to keep the body alive, such as breaking down food for energy and building new molecules.
Catalysing Reactions: Enzymes act as catalysts, making reactions happen faster.
Regulating Pathways: They control each step in metabolic pathways, ensuring reactions occur in the right order.
Controlling Speed: Enzymes can increase or decrease the rate of reactions depending on the body's needs.
Responding to Signals: Enzyme activity is controlled by hormones and other molecules to maintain balance, like regulating blood sugar.
87
How can some organisms survive in extreme conditions using enzymes?
Some organisms called extremophiles survive in extreme environments because their enzymes are specially adapted to work in those conditions:
In high temperatures, their enzymes have very stable structures that don’t denature, allowing reactions to continue.
In very acidic or alkaline environments, their enzymes have an optimum pH that matches the extreme condition.
In high pressures or salinity, enzymes and cell structures are adapted to maintain their shape and function, so metabolic reactions still occur.
88
explain how acid in the stomach
increases the efficiency of pepsin.
The acid in the stomach (hydrochloric acid) increases the efficiency of pepsin by providing the optimal acidic environment (pH 1.5 to 2) for the enzyme to work.
