Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOLOGY - EXCHANGE AND TRANSPORT SYSTEMS > DIGESTION AND ABSORPTION > Flashcards

DIGESTION AND ABSORPTION Flashcards

1
Q

What do glands produce and what is their function

A

enzymes that hydrolyse large molecules into smaller ones for digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why can’t large biological molecules be absorbed into the blood from the gut and give examples

A

too big to cross cell membrane, e.g. starch and proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are carbohydrates broken down into during hydrolysis

A

disaccharides and then monosaccharies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are fats broken down into during hydrolysis

A

fatty acids and monoglycerides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are proteins broken down into during hydrolysis

A

amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does amylase catalyse

A

conversion of starch into maltose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is amylase produced and released

A

salivary glands (into mouth) and pancreas (into small intestine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the major parts of the digestive system

A

1) oesophagus
2) stomach
3) ileum
4) large intestine
5) rectum
6) salivary glands
7) pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the job of the oesophagus

A

carry food from mouth to the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the stomach

A

muscular sac with an inner ayer that produces enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the role of the stomach

A

to store and digest food, especially proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the ileum

A

long muscular tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the role of the ileum

A

to further digest food by enzymes that are produced in its walls and by glands that release them into it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What adaptation does the ileum have

A

the inner walls are folded into villi to increase SA:V, which are then folded further into microvilli on the epithelial cells of each villus - means that there is a larger SA for absorption into blood stream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the role of the large intestine

A

to absorb water, mainly water secreted from the digestive glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the role of the rectum

A

to store the faeces until being removed via the anus through egestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where are the salivary glands situated

A

near the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do salivary glands secrete via a duct into the mouth

A

enzyme amylase that hydrolyses starch into maltose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where is the pancreas situated

A

below the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the role of the pancreas

A

to secrete pancreatic juice that contains proteases, lipase and amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the 2 stages of digestion

A

1) physcial breakdown

2) chemical breakdown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is physical breakdown

A

the break up of large pieces of food into smaller ones via structures such as the teeth or stomach wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does physical breakdown mean

A

the food is possible to ingest, and there is a larger SA:V for chemical breakdown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is chemial breakdown

A

hydrolysis carried out by enzymes of large, insoluble molecules into smaller soluble ones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the 3 main types of digestive enzymes and what do they hydrolyse
1) carbohydrases (carbohydrates-monosaccharides) 2) lipases (lipids-fatty acids and glycerol) 3) proteases (proteins-amino acids)
26
What is the usual events that occur when hydrolysing a carbohydrate
enzymes hydrolyse the molecule into smaller sectioons, and other enzymes hydrolyse them into their monomers
27
Explain the general process of starch digestion
1) amylase is produced in the mouth and pancreas which hydrolysis the alternate glycosidic bonds of the starch molecule, to produce maltose 2) Maltose is hydroyled by maltase (produced by lining of ileum) into alpha glucose
28
How does starch digestion occur in humans
1) saliva that contains salivary amylase and mineral salts enters mouth from salivary glands and mixed with food, which hydrolyses it into maltose (salts help to maintain neutral pH= optimal for enzyme)
29
How does starch digestion occur in humans 2
food enters stomach where conditions are acidic, whcih denatures amylase and stops further hydrolysis
30
How does starch digestion occur in humans 3
passed into small intestine where it mixes with pancreatic juice which contains pancreatic amylase that hydrolyses any remaining starch into maltose. pH is maintained at neutral by alkaline salts produced by pancreas &intestinal wall (so amylase can function)
31
How does starch digestion occur in humans 4
muscles in intestinal wall push food along the ileum whilst its epithelial lining produces maltase. Here it is a membrane bound disaccharidase, which hydrolyses maltose to alpha glucose
32
Why is the maltase in ileum describedc as membrane-bound disaccharidase
it is not released into the lumen of the ileum but is part of the cell-surface membranes of the epithelial cells that line the ileum
33
What are 2 other common disaccharies that are hydrolysed and what are they found in
1) sucrose - natural foods, fruits | 2) lactose - milk
34
What hydrolyses sucrose and descrbe
sucrase, breaks the single glycosidic bond to produce glucose and fructose
35
What hydrolyses lactose and describe
lactase, breaks single glycosidic bond to produce glucose and galactose
36
What are lipids hydrolysed by
lipases
37
Where are lipases produced and where do they function
in the pancreas, work in small intestine
38
How do lipases work
they hydrolse the ester bond found in triglycerides to form fatty acids and monoglycerides
39
What is a monoglyceride
glycerol molecule with a single fatty acid molecule attached
40
How and why are lipids emulsified
by bile salts, as it increases the lipids surface area
41
Where are bile salts produced by
the liver
42
What are micelles
the molecules formed after the monoglycerides fatty acids stick with the bile salts
43
What do peptidases hydrolyse
proteins
44
What are the types of peptidases
1) endopeptidases 2) exopeptidases 3) dipeptidases
45
What do endopeptidases do
hydrolyse bonds WITHIN a protein - hydrolyse the bonds between amino acids in the central region of a protein molecule to form a series of peptide molecules
46
Give 3 examples of endopeptidases and where theyre fromed/released
trypsin and chymotrypsin - synthesised in pancreas & secreted into small intestine pepsin - released into stomach by cells in stomach lining
47
What conditions does pepsin work best in and how are these met
acidic - provided by hydrochlorica acid in the stomach
48
What do exopeptidases do
hydrolyse the bonds AT THE END of the protein molecules (terminal amino acids) meaning they progressively release dipeptides and single amino acids (remove single amino acids from proteins)
49
What do dipeptidases do
hydrolyse bond between 2 amino acids of a dipeptide by hydrolysing the peptide bond between them
50
Where are dipeptidases often located
in the cell-surface membrane of epithelial cells in the small intestine
51
Are dipeptidases membrane-bound
yes
52
What causes lactose intolerance
the production of very little/no lactase so the lactose cannot be hydrolysed
53
What are the villi of the ileum located
between the lumen of the intestines, & the blood and other tissues inside the body
54
How do villi increase efficiency of absorption
1) increase SA:V for diffusion 2) very thin walled = short diffusion distance 3) contain muscle so are able to move, so can maintain diffusion gradients by mixing the content of the ileu 4) well supplied with blood vessels so blood can carry away absorbed molecules and hence maintain diffusion gradient 5) epithelial cells possess microvilli, further increase SA:V
55
How are amino acids and monosaccharides absorbed across cell membranes (w glucose, galactose, fructose)
diffusion and co-transport glucose = absorbed via active transport with sodium ions via co-transporter protein galactose = co-transport fructose = facilitated diffusion
56
How big are micelles
small, 4-7nm in diameter
57
How do monoglycerides and fatty acids transport across cell membranes
micelles come into contact with epithelial cells lining villi of ileum and break down, releasing the non-polar lipid-soluble monoglycerides and fatty acids which diffuse across the membrane
58
What happens to monoglycerides and fatty acids once they are inside the epithelial cells
transported to endoplasmic reticulum where they are recombined to form triglycerides
59
What are chylomicrons
special particles adapted for the transport of lipids
60
What happens to the triglycerides after the endoplasmic reticulum
continue in the golgi apparatus where they associate with cholesterol and lipoproteins to form chylomicrons
61
How do chylomicrons move out of the epithelial cells
exocytosis
62
What happens to the chylomicrons after they move out of the epithelial cells
enter lymphatic capillaries called lacteals that are found at the centre of each villus, then into the bloodstream
63
How are amino acids absorbed across cell membranes
(similar way to glucose and galactose), sodium ions actively transported out of the epithelial cells into the ileum then diffuse back into the cells through sodium-dependant transporter proteins and carry amino acids with them
64
What substance plays a role in the digestion and absorption of fatty acids
bile salts

BIOLOGY - EXCHANGE AND TRANSPORT SYSTEMS (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions