Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
AQA 4.2
ORGANISATION
4.2.2
Animal tissues, organs and organ systems
4.2.2.1 Human digestive
system- specification
• Cells are the basic building blocks of all living
organisms.
• A tissue is...
4.2.2.1 The human digestive
system - specification
• This section assumes knowledge of the digestive system studied in Key...
Digestive System LOs
• Recall the role of the digestive system, and the purpose of digesting
food
• State the sites of enz...
STARTER: Place in order of smallest
to largest
organism
organ
system
tissues
cells
organssmallest
largest
organism
organ
system
tissues
cells
organs
smallest
largest
The role of the digestive
system
The job of the digestive system is the break
down large insoluble food molecules into
sma...
Digestion quiz
Complete sheet as we go through the next few slides
The digestive system organs
The digestive system organs
Sites of enzyme production
Enzyme reactions
Enzymes
Enzymes are chemicals which break the larger
molecules down into smaller molecules. There are three
types of enzym...
Enzymes
• Carbohydrase chops carbohydrates into
smaller sugar molecules.
The three types of
enzymes are:
• Protease cuts p...
Proteins are digested in the stomach by an enzyme
called Protease. This enzyme needs to work in an
acidic environment. Pro...
Carbohydrates are chains of identical sugar
molecules. The enzyme called Carbohydrase
breaks the chemical bonds between th...
Fats are digested in two stages:
•Firstly bile (released by the gall bladder) allows
the fat to “mix” with water by breaki...
Enzymes of digestion
Word equations for the reactions of enzymes
• Challenge questions: If lipase is
added to some milk to digest the milk
fats, what will happen to the pH of the
milk? Ho...
Match the reactant
Enzymes; uses of products of
digestion; bile - specification
• Students should be able to use the ‘lock and key theory’ as...
Enzymes LOs
• Recall the word equations for the reactions of enzymes
• Know that enzymes are proteins with a specific shap...
Starter: write the correct enzyme name on the arrow for
each reaction
proteasecarbohydrase lipase
Lipids fatty acids + gly...
Starter: write the correct enzyme name on the arrow for
each reaction
protease
carbohydrase
lipase
Lipids fatty acids + gl...
Enzymes structure and function
• Enzymes are proteins
• They have a specific shaped active site
• A specific enzyme can on...
How enzymes work
What happens at the active site?
In the same way that a key fits into a lock, so a
substrate is thought to fit into an enz...
The lock and key model
Lock and Key model
• We use the 'lock and key' model to explain
enzyme action
Name the structure
Enzymes: true or false?
Factors affecting enzymes
If the temperature and pH changes sufficiently beyond
an enzyme’s optimum, the shape of the enzy...
Enzymes and pH
Enzymes and temperature
Enzymes and temperature
Enzyme inhibitors
Identifying enzyme terms
• Required practical activity 3:
• use qualitative reagents to test for a range of
carbohydrates, lipids and proteins.
• T...
• Required practical activity 4:
• investigate the effect of pH on the rate of reaction of amylase enzyme.
• Students shou...
Did iodine go brown for the presence of starch? (Tick or cross)
after iodine stays orange-brown.
Time (s) 0 10 20 30 40 50...
pH of solution Time taken for amylase to completely break down
the starch in seconds (s)
Aqa  digestive system tmid
Aqa  digestive system tmid
Aqa  digestive system tmid
Aqa  digestive system tmid
Aqa  digestive system tmid
Aqa  digestive system tmid
Aqa  digestive system tmid
Aqa  digestive system tmid
Aqa  digestive system tmid
Upcoming SlideShare
Loading in …5
×

Aqa digestive system tmid

718 views

Published on

PowerPoint based on the new 2016 AQA combined science specification

Published in: Science
  • Before coming across your guide, I wasn't highly motivated to study nor confident that I would achieve the best grades in my GCSEs. However, after reading about your success and what your program has done for others, it inspired me to do better and aim for the best results. At the end of the day, there is no reason why anyone cannot achieve the best grades in their studies... Your maths revision guide/strategy is fantastic! You have really opened my eyes as to where I've been going wrong all this time and what I should focus on, going forward. I've also applied your methods to other subjects too such as Science and seen a vast improvement in terms of revision and progress. I cannot thank you enough for sharing your strategy! I am very confident that, providing I follow your plan, I will excel in my final GCSE exams next year and most importantly, make my family proud! :)➤➤ http://t.cn/AirraVnG
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

Aqa digestive system tmid

  1. 1. AQA 4.2 ORGANISATION 4.2.2 Animal tissues, organs and organ systems
  2. 2. 4.2.2.1 Human digestive system- specification • Cells are the basic building blocks of all living organisms. • A tissue is a group of cells with a similar structure and function. • Organs are aggregations of tissues performing specific functions. • Organs are organised into organ systems, which work together to form organisms.
  3. 3. 4.2.2.1 The human digestive system - specification • This section assumes knowledge of the digestive system studied in Key Stage 3 science. • The digestive system is an example of an organ system in which several organs work together to digest and absorb food. • Students should be able to relate knowledge of enzymes to Metabolism. • Students should be able to describe the nature of enzyme molecules and relate their activity to temperature and pH changes. • Students should be able to carry out rate calculations for chemical reactions. • Enzymes catalyse specific reactions in living organisms due to the shape of their active site.
  4. 4. Digestive System LOs • Recall the role of the digestive system, and the purpose of digesting food • State the sites of enzyme production for amylases, proteases and lipases • Know that amylase is a carbohydrase • Construct simple word equations for the reactions of enzymes • Link the products of digestion to their uses • Know where bile is produced and stored • Explain how bile is important for efficient digestion
  5. 5. STARTER: Place in order of smallest to largest organism organ system tissues cells organssmallest largest
  6. 6. organism organ system tissues cells organs smallest largest
  7. 7. The role of the digestive system The job of the digestive system is the break down large insoluble food molecules into small soluble molecules. These can then be absorbed through the walls of the small intestine into the blood.
  8. 8. Digestion quiz
  9. 9. Complete sheet as we go through the next few slides
  10. 10. The digestive system organs
  11. 11. The digestive system organs
  12. 12. Sites of enzyme production
  13. 13. Enzyme reactions
  14. 14. Enzymes Enzymes are chemicals which break the larger molecules down into smaller molecules. There are three types of enzymes that you need to know about.
  15. 15. Enzymes • Carbohydrase chops carbohydrates into smaller sugar molecules. The three types of enzymes are: • Protease cuts proteins into the soluble amino acids. • Lipase breaks fats down into the smaller fatty acids and glycerol.
  16. 16. Proteins are digested in the stomach by an enzyme called Protease. This enzyme needs to work in an acidic environment. Protease breaks proteins (chains of different molecules) down into up to 20 different amino acids (four of which are shown). Proteins digestion Protease Folded up protein chain Amino acids
  17. 17. Carbohydrates are chains of identical sugar molecules. The enzyme called Carbohydrase breaks the chemical bonds between the individual sugar molecules (called glucose) as part of digestion. Starch/ carbohydrates Carbohydrase Long carbohydrate Small sugar
  18. 18. Fats are digested in two stages: •Firstly bile (released by the gall bladder) allows the fat to “mix” with water by breaking the fat up into smaller droplets. This is called emulsification. •Secondly, an enzyme called Lipase breaks the fats down into the smaller fatty acid molecules and glycerol. Bile Lipase + Fat Fatty acid Glycerol Fats
  19. 19. Enzymes of digestion
  20. 20. Word equations for the reactions of enzymes
  21. 21. • Challenge questions: If lipase is added to some milk to digest the milk fats, what will happen to the pH of the milk? How would you test for this? _________________________________________ _________________________________________ _________________________________________ _________________________________________ _________________________________________
  22. 22. Match the reactant
  23. 23. Enzymes; uses of products of digestion; bile - specification • Students should be able to use the ‘lock and key theory’ as a simplifed model to explain enzyme action. • Students should be able to recall the sites of production and the action of amylase, proteases and lipases. • Students should be able to understand simple word equations but no chemical symbol equations are required. • Digestive enzymes convert food into small soluble molecules that can be absorbed into the bloodstream. • Carbohydrases break down carbohydrates to simple sugars. Amylase is a carbohydrase which breaks down starch. • Proteases break down proteins to amino acids. • Lipases break down lipids (fats) to glycerol and fatty acids. • The products of digestion are used to build new carbohydrates, lipids and proteins. Some glucose is used in respiration. • Bile is made in the liver and stored in the gall bladder. It is alkaline to neutralise hydrochloric acid from the stomach. It also emulsi es 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.
  24. 24. Enzymes LOs • Recall the word equations for the reactions of enzymes • Know that enzymes are proteins with a specific shaped active site • Use the 'lock and key' model to explain enzyme action • Explain how the activity of enzymes are affected by temperature and pH • Investigate the effect of pH on the rate of reaction with amylase.
  25. 25. Starter: write the correct enzyme name on the arrow for each reaction proteasecarbohydrase lipase Lipids fatty acids + glycerol starch simple sugars proteins amino acids
  26. 26. Starter: write the correct enzyme name on the arrow for each reaction protease carbohydrase lipase Lipids fatty acids + glycerol starch simple sugars proteins amino acids
  27. 27. Enzymes structure and function • Enzymes are proteins • They have a specific shaped active site • A specific enzyme can only fit a specific molecule into its active site • So different enzymes will catalyse different reactions
  28. 28. How enzymes work
  29. 29. What happens at the active site? In the same way that a key fits into a lock, so a substrate is thought to fit into an enzyme’s active site. The enzyme is the lock, and the reactant is the key. enzyme reactant + enzyme-reactant complex ↔ products enzyme +↔ + ↔ ↔ +
  30. 30. The lock and key model
  31. 31. Lock and Key model • We use the 'lock and key' model to explain enzyme action
  32. 32. Name the structure
  33. 33. Enzymes: true or false?
  34. 34. Factors affecting enzymes If the temperature and pH changes sufficiently beyond an enzyme’s optimum, the shape of the enzyme irreversibly changes. normal denatured heat pH This affects the shape of the active site and means that the enzyme will no longer work. When this happens the enzyme is denatured.
  35. 35. Enzymes and pH
  36. 36. Enzymes and temperature
  37. 37. Enzymes and temperature
  38. 38. Enzyme inhibitors
  39. 39. Identifying enzyme terms
  40. 40. • Required practical activity 3: • use qualitative reagents to test for a range of carbohydrates, lipids and proteins. • To include: Benedict’s test for sugars; iodine test for starch; and Biuret reagent for protein. • AT skills covered by this practical activity: biology AT 2. • This practical activity also provides opportunities to develop WS and MS. Details of all skills are given in Key opportunities for skills development.
  41. 41. • Required practical activity 4: • investigate the effect of pH on the rate of reaction of amylase enzyme. • Students should use a continuous sampling technique to determine the time taken to completely digest a starch solution at a range of pH values. Iodine reagent is to be used to test for starch every • 30 seconds. Temperature must be controlled by use of a water bath or electric heater. • AT skills covered by this practical activity: biology AT 1, 2 and 5. • This practical activity also provides opportunities to develop WS and MS. Details of all skills are given in • Key opportunities for skills development.
  42. 42. Did iodine go brown for the presence of starch? (Tick or cross) after iodine stays orange-brown. Time (s) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 260 pH pH pH pH pH
  43. 43. pH of solution Time taken for amylase to completely break down the starch in seconds (s)

×