Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Class 3 > Lecture 26: Chemical Digestion > Flashcards

Lecture 26: Chemical Digestion Flashcards

(56 cards)

Start Studying
1
Q

What is chemical digestion?

A

when we release the nutrients necessary for our own growth and energy needs

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

Motility carries out mechanical digestion which is essential for chemical digestion. How?

A

Mechanical digestion breaks up the food into small pieces which is needed for chemical digestion

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

How does motility aid in chemical digestion?

A

mechanical digestion mixes the food with digestive enzymes

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

How does motility aid absorption?

A

by moving the food through the GI tract at a rate that allows for maximum absorption

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

How does secretion aid mechanical digestion?

A

the mucous coats the food and stops abrasion of epithelium

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

Why is secretion essential for chemical digesiton?

A

secretions contain digestive enzymes and electrolytes which ensure optimal pH for the enzymes

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

How does secretion aid in absorption?

A

By suspending food molecules in solution so they can be exposed to absorptive surfaces

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

What are the three main nutrients that undergo chemical digestion?

A
  • carbohydrates (sugars)
  • proteins
  • lipids (fats)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the main form of carbohydrates that we ingest?

A

storage polysaccharides

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

Give an example of a storage polysaccharide in grains and meat

A

starch in grains and glycogen in meat

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

What are storage polysaccharides?

A

very large complex chains of monosaccharides such as glucose

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

A large number of ________ molecules are bound together in long chains which is bound together in further chains to form _______ _______

A

glucose

storage polysaccharides

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

Starch and glycogen are storage carbohydrates that are joined by what type of bonds?

A

α 1-4 glycosidic bonds

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

As well as ingesting storage carbohydrates, we can also ingest _______

A

disaccharides

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

Give three examples of disaccharides and what monosaccharides they are made of

A
  1. sucrose made from glucose and fructose
  2. lactose made from glucose and galactose
  3. maltose made from two glucose molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

We also ingest a small number of monosaccharides. What monosaccharide do we ingest?

A

glucose

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

Proteins are required to be ingested for us to have ______ ______

A

amino acids

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

According to the lecture slide, how many amino acids are there and how many can we synthesise?

A

21 amino acids

12 can be synthesised

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

What is an essential amino acid?

A

amino acids that we need to access from our diet

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

Where are our two sources of protein?

A
  • diet

- endogenous proteins

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

What are endogenous proteins?

A

proteins secreted into our intestine such as enzymes and immunoglobins which we digest and reabsorb

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

Ingested proteins are long chains of ______ ______ linked by ______ bonds

A

amino acids

peptide

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

The lipids that we ingest are mainly

Study These Flashcards
A

triglycerides

24
Q

What does a triglyceride consist of?

Study These Flashcards
A

a glycerol back bone with 3 fatty acids attached

25
Fatty acids can be variable in chain length. How many carbons make up short chain fatty acids, medium chain fatty acids, long chain fatty acids respectively?
- short: less than 6 carbons - medium: 6 - 12 carbons - long: 12 - 24 carbons
26
Why do we need chemical digestion?
because we ingest nutrients in the form of large complex molecules (carbs, proteins, lipids) but we can absorb nutrients as small molecules
27
What is the purpose of chemical digestion?
to reduce the size of nutrients to allow them to be absorbed
28
Where does chemical digestion occur?
At the surface of food particles
29
During chemical digestion, we break up molecules into its constituent parts. What are the constituent parts of sugars, proteins and fats?
- sugars: monosaccharides - proteins: amino acids - fats: monoglycerides and free fatty acids
30
Chemical digestion utilises ________ enzymes
chemical
31
What are digestive enzymes?
Extracellular, organic catalysts
32
Are digestive enzymes specific?
yes | they need different enzymes for different substrates
33
Give the different substrates for amylase, protease and lipase
Amylase: carbohydrates Proteases: proteins Lipases: fats
34
Enzymes have an optimal pH. Give the optimal pH for salivary, gastric and small intestinal enzymes
Salivary: alkaline Gastric: acidic Small intestinal: alkaline
35
What are the two stages of chemical digestion?
luminal digestion | contact digesiton
36
What is luminal digestion?
the initial digestion involving enzymes secreted into the lumen
37
Give examples of enzymes involved in luminal digestion in the mouth, stomach and small intestine
salivary amylase pepsin pancreatic enzymes
38
What is contact digestion?
involved enzymes produces by enterocytes and attached to brush border of the enterocytes
39
Where does contact digestion only occur?
in the small intestine
40
What are enterocytes?
epithelium of the small intestine
41
Describe the luminal digestion of carbohydrates
salivary amylase in the mouth converts polysaccharides to oligosaccharides and pancreatic amylase converts oligosaccharides to disaccharides in the small intestine
42
Describe contact digestion of carbohydrates
Disaccharides are converted to monosaccharides by different enzymes attached to the brush border
43
What are three enzymes involved in the contact digestion of carbohydrates and what do they break down?
- Sucrase breaking down sucrose to glucose and fructose - lactase breaking down lactose to glucose and galactose - maltase breaking down maltose into two glucose molecules
44
Describe the luminal digestion of proteins
Pepsin in the stomach and trypsin, chymotrypsin, carboxypeptidase in the small intestine convert proteins to polypeptides
45
Describe the contact digestion of proteins in the small intestine
peptidases attached to the brush border convert polypeptides into individual amino acids
46
What is different about the chemical digestion of fats compared to the digestion of proteins and carbohydrates?
there is no contact digestion
47
What is the main digestive enzyme involved in digestion of lipids?
pancreatic lipase
48
What are the four phases of the chemical digestion of fat?
1. emulsification 2. stabilisation 3. digestion 4. formation of micelles
49
Describe the emulsification stage of fat digestion
- motility breaks up fat droplets into small droplets which forms an emulsion
50
Where does the emulsification phase of fat digestion occur and what are the processes occurring here that allow that to happen?
stomach - retropulsion | small intestine - segmentation
51
Where does the stabilisation phase of fat digestion occur?
in the small intestine
52
What is involved in emulsification?
breaking up large fat droplets into smaller droplets
53
What is the role of bile salts in the stabilisation phase of fat digestion?
Bile salts secreted by the liver and concentrated in the gallbladder are released into the small intestine with the arrival of food. They have both a hydrophobic side and a hydrophilic side. They stabilise the emulsion in the small intestine by preventing the droplets from coalescing due to like charges repelling
54
Describe the hydrolysis stage of lipid digestion
colipase binds to the bile salt around the small droplets and anchors pancreatic lipase at the surface of the droplet to convert the triglycerides to monoglycerides and free fatty acids
55
What is the purpose of micelle formation around free fatty acids and monoglycerides?
FFA and MAGs are insoluble in water so they need to be kept in solution through the formation of the micelles.
56
What are micelles?
small droplets made from bile salts surrounding the FFA and MAGs

Class 3 (41 decks)

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