Digestion

  • Created by: Hindleyc
  • Created on: 18-06-18 15:48
What is digestion?
Where large insoluble molecules are hydrolysed/broken down into small soluble ones that can be absorbed across cell membranes
1 of 45
What is the physical breakdown?
Large food into small pieces by teeth- making food possible to ingest and give larger SA for chemical digestion
2 of 45
Where else is food physically broken down?
Stomach and SI- churned by muscles in S walls to physically breakup food and in SI
3 of 45
What does Chemical digestion do?
Large insoluble molecules into small soluble ones
4 of 45
What is it carried out by and what is the process?
Enzymes and hydrolysis
5 of 45
What is hydrolysis?
Splitting molecules by adding water to chemical bonds that hold them together
6 of 45
What are enzymes?
Specific
7 of 45
How are they used in a large molecule?
More than one needed to break down large molecule
8 of 45
How?
1 enzyme breaks large molecule into sections then 1 or more break sections down
9 of 45
How are they made?
In diff parts of digestive system in correct sequence and nearly all finish in Small intestine so products only have to move into blood
10 of 45
What do carbohydrates do?
Break down Carbohydrates ultimately into monosaccharides
11 of 45
Where is Amylase produced? What does it hydrolyse and how? why?
Mouth and pancreas. H starch- every other glycosidic bond so only disaccharide maltose due to shape of active site
12 of 45
EQN?
Amylase+starch=maltose
13 of 45
2 types of Amylase?
Salivary amylase and pancreatic amylase
14 of 45
What does salivary amylase do? what help maintain PH around neutral? what does it do little of and why? adv?
Starts digestion of starch- starts to create maltose and lubricates food. Mineral salts. Little digestion as quickly denatured in stomach and helps to clean mouth and reduce bacterial infection
15 of 45
What does pancreatic juice contain?
Lipase, protease, hydrogen carbonate ions (alkaline) and PANCREATIC AMYLASE
16 of 45
What does it do? how?
Digests all remaining starch in small intestine. Digests starch molecules from ends of chain into 2 glucose units- di (maltose)
17 of 45
What keeps PH around 7/8 and what does this allow?
Alkaline salts in pancreatic juice and from intestine wall so amylase can function
18 of 45
How does it get into upper parts of SI?
Duct squirts down in upper part
19 of 45
Where is starch digested?
Mouth and upper part of SI-( not through pancreas)
20 of 45
What are disaccharidases?
Bound to membrane of ileum epithelial cell and complete digestion
21 of 45
What do Carbs make up ?
plant fibres can't be digested so move through
22 of 45
2nd enzyme for Carbohydrate digestion ?
Maltase
23 of 45
What is Maltase?
Membrane bound disaccharidase the breaks down disaccharides
24 of 45
Where is it produced? where is it sat?
In lining of intestine . Sat in membrane in cells lining intestine
25 of 45
What is exposed?
Active site
26 of 45
Adv of them?
Products ready for absorption as released right next to where absorbed (epithelial cells of villus)
27 of 45
EQN?
Maltose+Maltase=A glucose
28 of 45
Overall carb digestion
Starch+Amylase=Maltose+Maltase=A glucose
29 of 45
What digest lipids (fats and oils) ?
Lipases
30 of 45
EQN?
Lipid+lipase= glycerol + fatty acids
31 of 45
Where lipase normally made? where are they secreted into? what do they break?
In pancreas, into Small intestine and ester bonds
32 of 45
Where are bile salts made and stored, ph? what do they do and what do they have?
Liver, gall bladder. Alkaline- neutralise acid (ph2) and emulsify lipids. Have hydrophilic and hydrophobic parts
33 of 45
What do they do?
Interact with lipid and water breaking large lipids up into smaller droplets which mix with water- micelles increasing SA for lipase digestion
34 of 45
What is there a joint effort by for lipid digestion ?
Lipases and bile
35 of 45
2 Functions of bile?
Neutralise acid and emulsify fats into smaller droplets for lipid digestion
36 of 45
How are proteins digested?
Proteases break down proteins ultimately into AA
37 of 45
What are the 3 enzymes?
endopeptidase and exopeptidase and membrane bound Dipeptidase
38 of 45
Where is Pepsin produced?/found and whats its optimum PH?
Stomach and 1/2
39 of 45
Where are Endo and exo peptidases produced and secreted?
Synthesised in pancreas and secreted in SI
40 of 45
Where does P digestion begin?
Stomach in acidic conditions- p long molecule
41 of 45
What do exopeptidase do?
Hydrolyse peptide bonds at end of peptide molecule- break end AA off chain
42 of 45
What do endopeptidases do?
Hydrolyse peptide bonds within a protein - internal peptide bonds creating dipeptides
43 of 45
Eg of exopeptidase?
Dipeptidase which separates dipeptides gives individual AA often membrane bound to epithelial cells in SI
44 of 45
protein digestion ?
Stomach with endopeptidases eg pepsin later in SI when mixed with exopeptidase (dipeptidases)
45 of 45

Other cards in this set

Card 2

Front

What is the physical breakdown?

Back

Large food into small pieces by teeth- making food possible to ingest and give larger SA for chemical digestion

Card 3

Front

Where else is food physically broken down?

Back

Preview of the front of card 3

Card 4

Front

What does Chemical digestion do?

Back

Preview of the front of card 4

Card 5

Front

What is it carried out by and what is the process?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules, organic chemistry and biochemistry resources »