Brainscape's Knowledge GenomeTM

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


See full index

Biology Y1 > 3.3.1: Enzymes & digestion > Flashcards

3.3.1: Enzymes & digestion Flashcards

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

what is mechanical digestion and why does it happen

A

teeth break down large pieces into smaller pieces - to increase surface area for digestion and so increase rate of digestion

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

What is chemical digestion

A

involves enzymes, hydrolysing of bonds - glycosidic, peptide, ester - breakdown of large insoluble molecules to small soluble ones

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

explain why it is necessary for food to be digested in order to be absorbed into our body

A

to make it smaller and soluble so that it can be transported across membranes to be absorbed into the blood plasma

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

list 3 functions of mucus in the digestive system

A

1 - neutralise acid
2 - provides lubrication
3 - protects gut wall from acid erosion

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

state where enzymes and digestive chemicals are secreted from and where they go, as part of extracellular digestion

A

enzymes are secreted from:
salivary glands into mouth
gastric glands into stomach
pancreas into duodenum
digestive chemicals are secreted from pancreas into duodenum

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

state where intracellular digestion happens and what happens in the process

A

occurs in the epithelial cells of ileum, they hydrolyse disaccharides and dipeptides

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

describe the process of carbohydrate digestion (starch)

A

amylase hydrolyses starch to make maltose which is then hydrolysed by maltase to make glucose

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

describe what the role of amylase is, where it is found and its optimum pH

A

hydrolyses glycosidic bonds in starch to produce maltose. Amylase is found in saliva and pancreatic juice, its optimum pH is 8

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

describe what the role of maltase is, where it is found and its optimum pH

A

hydrolyses glycosidic bonds in maltose to produce glucose. Maltase is found in epithelial cells in ileum and its optimum pH is 8

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

describe and explain the process of protein digestion

A

pepsin (endopeptidase) in the stomach hydrolyses peptide bonds in protein into polypeptide chains
trypsin (endopeptidase) in the duodenum hydrolyses the polypeptide chains into smaller polypeptide chains. Exopeptidases in the duodenum remove the amine group from the polypeptide chain to produce amino acids and dipeptides (by hydrolysis)
Dipeptidases (exopeptidases) in the ileum hydrolyse the dipeptides into amino acids

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

what is the difference between exopeptidases and endopeptidases

A

exo = hydrolyse the end of the polypeptide chain
endo = hydrolyse the inside of the polypeptide chain

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

name the 2 endopeptidases involved in protein digestion and state where they are found, their optimum pH

A

pepsin - stomach pH 2
trypsin - duodenum pH 8

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

state where exopeptidases are found and give 3 examples

A

found in pancreas and epithelial cells of ileum: 1 - carboxypeptidase
2 - aminopeptidase
3 - dipeptidase

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

explain why it is more efficient for the endopeptidase enzymes to act before the exopeptidases

A

the endopeptidases hydrolyse the internal peptide bonds in the chain first which increases the surface area for exopeptidases to hydrolyse the external peptide bonds

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

Describe and explain the process of lipid digestion

A

process of mechanical digestion happens first: bile salts emulsify lipids into micelles, this increases surface area for lipase action. Afterwards, process of chemical digestion happens: lipase hydrolyses ester bonds in the micelles into monoglycerides and fatty acids

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

where is bile produced and stored, and how is it released and where to

A

bile is produced in the liver, stored in the gallbladder, released via the bile duct to the duodenum

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

what two things does bile contain

A

1 - bile salts that emulsify lipids into micelles
2 - sodium hydrogen carbonate that neutralises stomach

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

name the substrate that amylase hydrolyses and the product made

A

starch -> maltose

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

name the substrate that endopeptidase hydrolyses and the product made

A

proteins/polypeptides -> smaller polypeptide chains

20
Q

name the substrate that exopeptidases/dipeptidases hydrolyses and the product made

A

shorter polypeptides -> dipeptides and amino acids

21
Q

name the substrate that lipase hydrolyses and the product made

A

lipids -> monoglycerides and fatty acids

22
Q

name the substrate that disaccharidases hydrolyses and the product made

A

disaccharides -> monosaccharides

23
Q

where are the sites of secretion of amylase and the sites of action

A

salivary glands -> mouth and
pancreatic juice -> duodenum

24
Q

where are the sites of secretion of endopeptidase and the sites of action

A

gastric glands -> stomach and
pancreas -> duodenum

25
Q

where are the sites of secretion of exopeptidases/dipeptidase and the sites of action

A

pancreas -> duodenum and
epithelial cells -> ileum

26
Q

where are the sites of secretion of lipase and the sites of action

A

pancreas -> duodenum

27
Q

where are the sites of secretion of disaccharidases and the sites of action

A

epithelial cells -> ileum

28
Q

Describe the process of mechanical digestion in the mouth

A

teeth - increases surface area for chemical digestion

29
Q

Describe the process of chemical digestion in the mouth

A

salivary gland secretes saliva which contains: amylase - breakdown starch
mucus - lubrication
mineral ions - maintain pH

30
Q

What is the pH in the mouth

A

6.5-7.5

31
Q

Describe the function of the oesophagus

A

circular muscle contracts to squeeze the gut and longitudinal muscle contracts to shorten the gut. Both muscles work together - peristalsis - to move the food down the oseophagus

32
Q

What cells in the oesophagus secrete mucus and provide lubrication

A

goblet cells

33
Q

Describe the process of mechanical digestion in the stomach

A

stomach muscles contract to churn contents to form acidic chyme - increasing surface area for chemical digestion

34
Q

Describe the process of chemical digestion in the stomach

A

Gastric gland secretes gastric juice which contains:
endopeptidases - hydrolyse peptide bonds
mucus - lubrication and protects stomach wall from acid
HCl - maintains pH and activates enzymes and kills bacteria

35
Q

What is the pH in the stomach

A

2

36
Q

what is the role of the duodenum, and describe the gland in it

A

the duodenum is the main site of chemical digestion, the Brunner’s gland is in the gut wall, which releases mucus

37
Q

what is the pH of the duodenum

A

7-8

38
Q

What common role do mucus, hydrogen carbonate ions, and sodium hydrogen carbonate have in the digestive system

A

they all neutralise stomach acid

39
Q

Describe the structure of the ileum

A

lumen of ileum, microvilli, epithelial cell of ileum, blood capillary

40
Q

Where are the enzymes for disaccharides located in the ileum and what advantage does this give in terms of digestion

A

they are all in the microvilli, and so as the disaccharides are absorbed into the blood capillary, they are broken down into monosaccharides

41
Q

What is the role of the colon in the digestive system and how does it carry this role out

A

egestion of carbon based material -> faeces
colon absorbs remaining water along with any vitamins -> this is to have solid faeces which stimulates peristalsis

42
Q

what are three things present in the faeces that provide bulk and help to solidify the faeces in the colon

A

1 - bacterial cells
2 - sloughed cells (cells rubbed off of gut wall)
3 - undigested material (cellulose)

43
Q

what do bacterial cells, sloughed cells (cells rubbed off of gut wall), undigested material (cellulose) present in the faeces in the colon help with

A

provides bulk, helps solidify faeces

44
Q

name the products of digestion

A

amino acids, glucose, glycerol and fatty acids

45
Q

why can’t starch, proteins and lipids be absorbed into the blood

A

too large and insoluble

46
Q

explain why humans can’t digest cellulose

A

humans lack the enzyme cellulase to be able to break down cellulose

Biology Y1 (53 decks)

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