Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A-LEVEL BIO > 1: BIOLOGICAL MOLECULES - DIGESTION AND ABSORPTION > Flashcards

1: BIOLOGICAL MOLECULES - DIGESTION AND ABSORPTION Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Why does digestion happen?

A

digestion means that molecules can be easily absorbed from the gut into the blood to be transported around the body to be used by cells

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

What enzyme catalyses the breakdown of starch?

A

amylase

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

What are the sites of amylase production/use?

A
  • salivary glands
  • pancreas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the product of the digestion of starch?

A

maltose

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

What enzymes catalyse the breakdown of disaccharides?

A

disaccharidases

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

What are the sites of production/use of disaccharidases?

A

membrane bound in the ileum

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

What disaccharidase catalyses the breakdown of maltose?

A

maltase

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

What disaccharidase catalyses the breakdown of sucrose?

A

sucrase

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

What disaccharidase catalyses the breakdown of lactose?

A

lactase

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

What are the products of the digestion of maltose?

A

2 alpha glucose molecules

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

What are the products of the digestion of sucrose?

A

glucose + fructose

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

What are the products of the digestion of lactose?

A

glucose + galactose

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

What type of bond is hydrolysed in the digestion of polysaccharides/disaccharides?

A

glycosidic bonds

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

What enzymes catalyse the breakdown of polypeptides?

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

What bonds do endopeptidases break?

A

peptide bonds within the polypeptide chain

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

What bonds do exopeptidases break?

A

peptide bonds at the end of the polypeptide chain

17
Q

What are the products of polypeptide digestion with endopeptidase?

A

2 shorter polypeptide chains

18
Q

What are the products of polypeptide digestion with exopeptidase?

A

shorter polypeptide chain + 1 amino acid

19
Q

What is the site of production/use of exopeptidases and endopeptidases?

A

the stomach

20
Q

What enzymes catalyse the breakdown of dipeptides?

A

dipeptidases

21
Q

What are the products of dipeptide digestion?

A

2 amino acids

22
Q

What is the site of dipeptidase production/use?

A

membrane bound in the small intestine

23
Q

What type of bonds are hydrolysed in the digestion of polypeptides and dipeptides?

A

peptide bonds

24
Q

What enzyme catalyses the breakdown of lipids?

A

lipase

25
Q

What is the site of lipase production/use?

A

the pancreas

26
Q

What are the products of lipid digestion?

A

monoglycerides + 2 fatty acids

27
Q

What type of bond is hydrolysed in the digestion of lipids?

A

ester bonds

28
Q

What is the function of bile salts?

A

bile salts emulsify lipids (cause the lipids to form small droplets)

29
Q

What organ produces bile salts?

A

the liver

30
Q

What is the benefit of emulsifying lipids?

A
  • several small lipid droplets have a larger surface area than a single large droplet (for the same volume of lipid)
  • this means that the surface area available for lipase to work on increases
31
Q

What happens after the lipids are broken down by lipase?

A

monoglycerides and fatty acids stick with the bile salts to from micelles

32
Q

What is the function of micelles?

A

help products of lipid digestion to be absorbed

33
Q

How are lipids absorbed?

A
  • micelles move monoglycerides and fatty acids towards the epithelium
  • because micelles constantly break up and reform they release monoglycerides
  • monoglycerides and fatty acids are lipid soluble so they diffuse directly across the epithelial cell membrane
  • monoglycerides and fatty acids form triglycerides (produced by SER)
  • golgi body packages triglycerides into chylomicrons
  • chylomicrons move from the epithelial cell into the lacteal by exocytosis
34
Q

How are glucose and galactose absorbed?

A

glucose and galactose are absorbed across the ileum epithelium into the bloodstream by active transport via co-transporter proteins

35
Q

How is fructose absorbed?

A

fructose is absorbed by facilitated diffusion

36
Q

Describe the co-transport of glucose across the ileum epithelium (6 marks)

A
  • Na^+ ions pumped out of epithelial cell by active transport/sodium-potassium pump into blood
  • maintaining Na^+ ion conc gradient between lumen of ileum and epithelial cell
  • glucose moves in with Na^+ ion into epithelial cell via co-transporter protein
  • Na^+ ion moves down conc gradient whilst glucose moves against conc gradient
  • glucose moves into blood by facilitated diffusion via carrier protein
37
Q

How are amino acids absorbed?

A
  • amino acids are absorbed via co-transport
  • Na^+ ions are actively transported out of the ileum epithelial cells into the blood which creates an Na^+ ion conc gradient
  • Na^+ ions can then diffuse from the lumen of the ileum into the epithelial cells through sodium-dependent transporter proteins, carrying the amino acids with them

A-LEVEL BIO (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions